The Elderly Novice Virtual Organist

The Virtual Pipe Organ Explained

This page is a beginner's guide to the virtual (pipe) organ. It explains what a virtual organ is, why it is the next best thing to a real pipe organ, how to buy one, and the system that I assembled. It is aimed at people who want a classical or theatre organ for use in the home. It does not cover the issues with using such an instrument in a public building.

My experience is confined to the use of Hauptwerk virtual organ software on Windows. I therefore do not offer comments on the use of Hauptwerk on macOS, nor on other virtual organ software such as GrandOrgue. And I am no Hauptwerk guru, having used only a small proportion of its function. Nonetheless, I believe that the points I make here should be read by all prospective purchasers of a virtual organ, to avoid making expensive mistakes.

Link Types

This Page

This Website

External Website

Glossary Item

1 Why a Virtual Organ?

If you want an instrument that serves as a pipe organ, you have three choices:

1.1 Real Pipe Organs

These are typically very large and very expensive; only a very simple instrument with just a few small ranks could be accommodated in a normal room. And then, apart having very limited capabilities, it might not sound very pleasant, as a pipe organ requires a favorable acoustic environment with plenty of space for its sound to blossom.

Although pipe organs normally have a very long lifespan, they require a significant amount of maintenance, including regular tuning. The high purchase and maintenance costs of a pipe organ (many times that of a digital one) make it uneconomic for ordinary use. For this reason, apart from being uncommon in the home, pipe organs are frequently being replaced by digital organs in buildings such as churches.

However, while the sound quality from electronic organs is better now than it used to be, it is still not really good. Only a pipe organ is the real thing, and it remains the instrument of choice for quality applications.

1.2 Electronic (Digital) Organs

These have been around since the 1930s. Early electronic organs were analog and used vacuum tubes; they were often referred to as "toasters" on account of the heat they produced. Transistors were introduced in the late 1950s, and digital organs date from the 1970s.

Most, such as the majority of Hammond organs, are suitable only for popular music. However, others are aimed at replacing a traditional pipe organ in buildings such as churches. Digital organs are becoming increasingly common in this role, due to their considerably lesser cost and size, while producing adequate sound for accompanying congregational singing. Digital organs are also often used to emulate a pipe organ in the home.

They are normally sold as complete self-contained systems, including console and audio components. This eases purchase and maintenance, thus making them attractive to institutions such as churches. When installed in buildings, they may be voiced in location just as would be the case with a pipe organ, and use custom-designed audio systems. In most cases, the sounds are synthesized from recorded pipe organ samples, but they may also be modeled by additive synthesis.

The quality of sound produced by an electronic organ is determined firstly by the generation (synthesis) of sounds, and secondly by their reproduction (via amplifiers, and especially, speakers). The second area also involves issues with the interaction of the speakers with their acoustic environment, and loudpspeaker placement is vitally important. But although the sound from even the best high-fidelity loudspeakers does not match that from natural sound sources (and indeed there are considerable differences between them), the bigger problem appears to be in sound generation.

Although one might expect that with developments in digital signal processing, a highly realistic and natural sound could be achieved, this is clearly not the case. Unlike with the piano, the changes and irregularities that make pipe organs sound natural are subtle; nonetheless (and perhaps even because of this), they seem to be difficult to model. The results are sterile and lack natural liveliness. If the organ is used in a dead acoustic (such as in the home), reverberation must also be synthesized, and this is also likely to lack realism.

It is my view (clearly shared by many others) that the sounds from an electronic organ vary from (at best) bland, to (at worst) ghastly. The good news, if the organ has MIDI output, is that it may be possible to ditch the built-in sounds and convert it to a virtual organ...

1.3 Virtual (Pipe) Organs

The virtual (pipe) organ (sometimes referred to as a VPO) is a much more recent development than the digital organ. Complete software was first available only in 2002, and was then limited by the processing power of computers at that time. Before the turn of the millennium, virtual organs for general use were not feasible at all, due to insufficient computing power.

Unlike a digital organ, a virtual organ:

A general-purpose computer offers much more processing power than that of the digital organ. Nonetheless, high-quality modeling of a large pipe organ became possible only with the advent of 64-bit computing, which removed the 4 GB limit on RAM size. This was furthered by falling memory prices and multi-core processors (which the multi-processing of Hauptwerk should be able to exploit fully).

Recordings of individual pipes from a real pipe organ are combined in real time in response to messages from MIDI devices and controls on the computer user interface. This can provide extremely realistic modeling of a real instrument.

Moreover, while a digital organ has only one fixed set of sounds, a virtual organ offers a choice of hundreds of instruments of many different types. As well as classical organs, these include theatre organs, and other instruments such as harpsichords. A virtual organ may have many of these installed, and a different instrument can be loaded at any time.

For the best possible realism, several high-quality recordings are made of each note for each stop (so, except for multi-rank stops, each individual pipe). This is called sampling; this term reflects the fact that the sound from a pipe varies, so recordings of the same pipe will differ somewhat. Each recording is known as a sample, and the set of samples required to model an organ is known as a sample set.

Even a moderate-sized organ requires many thousands of samples, and to avoid data accessing delays, all must be loaded into memory before the organ is used. This may require a very large amount of RAM. Processing requirements are also likely to be high, due to the large number of samples that must be handled simultaneously.

MIDI devices include keyboards (manuals and pedalboard), pistons (thumb and toe), and expression pedals. While stop controls are typically operated from a touchscreen, some virtual organs feature MIDI drawknobs and/or tabs.

Like the real pipe organ (but unlike the digital organ), the virtual organ can take many forms. It is possible to assemble a virtual organ from components (which are often used or self-built) at relatively low cost. These systems exhibit considerable diversity; some have the look and feel of a real pipe organ console, while others with multiple screens expose the computer function. As well as self-assembled systems, numerous complete turnkey and computer-ready products are available that can make purchase and assembly as easy as with a digital organ.

But the numerous options may make choosing a suitable virtual organ something of a challenge. The section Getting a Virtual Organ should help the prospective purchaser to make the right choices.

1.4 Virtual versus Digital

While a digital organ is limited to one fixed set of sounds of questionable quality, a virtual organ can accurately model a large number of real instruments. For this reason, a virtual organ is probably a better choice than a digital one for the home enthusiast.

However, a digital organ is easier to buy and use, as:

But this ease of purchase and use also comes with disadvantages.

A single package is easy to choose and buy, and having maintenance under one roof makes it attractive to institutions. However, there are far fewer options available to the purchaser, and little or no ability to upgrade the system to meet future requirements. It is possible for an individual to put together a component-based virtual organ with a much more favorable price/quality ratio than that of a package.

Moreover, turnkey virtual organs have now been available for several years. There are also virtual organs on the market that include the furniture and MIDI devices, requiring only the addition of a computer system. It is also possible to convert a digital organ to a virtual one this way.

Having dedicated hardware and firmware makes a digital organ easy to use. In contrast, virtual organ software is far from straightforward, and requires a significant learning curve. To a large degree this is because it is general-purpose, being designed to work with a wide variety of different systems. There may be numerous problems getting the system to work, particularly in connection of MIDI devices. And using a Windows-based computer can be problematic, especially turning the system on and off.

But the other side of this is much greater function. Virtual organ software, while complex, provides a rich array of features. The computer can also be used for auxiliary applications; for example, displaying music, playing audio and video recordings of one's favorite interpretations, and a metronome.

And computer hardware made with ubiquitous components is easier for the end user to maintain. With a digital organ, servicing would almost certainly have to be done in conjunction with the manufacturer, and require special parts.

But quite different criteria apply to the home enthusiast and an institution such as a church. In the latter case, the digital organ will probably continue to prevail, especially since the difficulties with using a virtual organ in a public building may be considered unacceptable. And such an institution would probably have a maintenance contract with the supplier.

2 Software

This section focuses on the Hauptwerk virtual organ software from Milan Digital Audio, with references to other virtual organ systems.

Software is discussed before hardware, as this primarily determines system capabilities. All Hauptwerk virtual organs have the same underlying function, even though their hardware ranges from the sublime to the gorblimey!

2.1 Summary of Hauptwerk

The most substantial and best-supported virtual organ software is Hauptwerk. Being introduced in 2002, Hauptwerk is now a mature product that will work with a wide range of hardware and software.

With several hundred sample sets available, Hauptwerk offers a far greater choice than any other system. These range from positives to large cathedral and concert organs; there are also theatre organs, harpsichords, and other instruments.

Hauptwerk also has the richest feature set; the following is a brief summary of some of its features:

Hauptwerk comes in two editions: Lite and Advanced. Most users will probably need the Advanced edition, especially as the maximum polyphony allowed with the Lite edition remains at 1024. This was not such a severe limitation when it was introduced as it is now with greater hardware capabilities and larger instruments.

Both editions are available on monthly or yearly subscription, the attraction of which I fail to understand, unless the system would only be used for a very occasional month. But its use would normally be ongoing, and a Perpetual license can be bought for 2.5 times the cost of a yearly subscription. It does not take a mathematical genius to discern that a subscription would be vastly uneconomical for a once-in-a-lifetime system purchase. Thankfully, a Perpetual license is still available for the Advanced edition, at US$599.

2.2 Development of Hauptwerk

Hauptwerk was originated by Martin Dyde in 2001. Apart from leading to the current Hauptwerk, his work is also the basis of GrandOrgue. This was originally called myOrgan, and introduced in 2006. It was generally considered to be a rip-off of Hauptwerk 1, with the same Organ Definition File format and screens (although apparently different source code). It was released under the Creative Commons license as GrandOrgue in 2009.

From 2006, Martin Dyde traded Hauptwerk through a company named Crumhorn Labs. In September 2008, he sold his company to Milan Digital Audio; from now on, the business and administrative side would be handled by Brett Milan. The St Annes church where the included sample set was recorded is in Moseley, Birmingham, UK, in the area where Martin Dyde was living when he originated Hauptwerk.

HW1 was released in August 2002 with the original version of the St Annes organ sample set. It was for Windows only. Stops were operated by MIDI Note messages. One limitation was that the swell simulation changed only the volume, not the sound quality.

HW2 was released in May 2006. It came in three editions: Evaluation, Studio, and Concert. It introduced piracy protection via a HASP USB dongle. The Organ Definition File format was redesigned; apart from supporting much greater function, this meant that sample sets developed for Hauptwerk would not work on GrandOrgue (then myOrgan). The swell simulation now supported changes in tonal quality as specified in the sample set. Other enhancements were more flexible MIDI configuration, and phase alignment of release samples. It was available as a VSTi plugin. A port to the Mac was added later.

HW3 was released in November 2007. It came in three editions: Free, Basic, and Advanced (the free edition featured a bell that rang every few seconds). It now supported macOS as well as Windows. It also added support for multiple console windows, and per-pipe voicing (both available only with the Advanced edition).

HW4 was released in April 2011. It also came in Free, Basic, and Advanced editions. This was a big release, which featured a newly-recorded St Annes sample set that took advantage of increasing memory capacity, as well as new Hauptwerk function. Among the other numerous improvements were: a redesigned interface optimized for touchscreens, redesigned settings windows, a MIDI recorder / player, MIDI learn (auto-detect), real-time performance and activity meters, user-defined combinations and crescendos, floating divisions, master couplers, and pitch adjustment independent of temperament. It also introduced the Custom Organ Design Module. Enhancements available only with the Advanced edition included a VST/AU link to allow streaming of audio and/or MIDI to an external application (this replaced the previous VSTi).

HW5 was released in December 2019. This also introduced many new features, although perhaps fewer than HW4. HW5 removed the Free edition, and introduced subscription pricing for both editions (Lite and Advanced) as an alternative to a perpetual license. Piracy protection was now by iLok License Manager. A 64-bit platform was now required. Enhancements in both editions included: operation of controls via MIDI and mouse, modeling of tracker action and velocity sensitivity, support for multi-layered samples, and support for ASIO (Windows) and Core Audio (Mac) audio drivers. Enhancements available only with the Advanced edition included: real-time impulse response reverb, audio routing, multi-channel audio, surround sound, audio mixing, more per-rank voicing adjustment, and air-flow turbulence modeling.

HW6 was released in November 2020. Now the Lite edition was available only on subscription. As can be seen, this follows hard on the heels of HW5, but offers few significant improvements. About the only functional (as opposed to user interface) enhancement is a higher-definition audio option. But like the other enhancements, this has very limited scope, and is of absolutely no benefit to the majority of users.

HW7 was released in January 2022 with even less, but including a revision of the higher-definition audio. It seems that this has convinced many people that the sound quality from Hauptwerk improves with each new release!

HW8 was released in August 2023 with a similar level of new function. Version 6 was now considered obsolete and no longer supported.

So, since the introduction of subscription pricing in HW5, there has clearly been a policy of much more frequent major versions, even though they have little new to offer (which the release information struggles to candy floss). This is no doubt to both promote the purchase of subscription licenses, and increase sales of updates to those who insist on having a perpetual license.

But as Hauptwerk is now a mature product, future versions are likely to continue to include only superficial changes. This is not only because important core function not yet included is little or none, but also because changes in this area would impact product stability. So new features are likely to be at best "nice to have" (and then probably only for a minority of users), not "must have", or even "should have". My obsolete HW6 leaves nothing that I desire that is likely to be remedied by an update.

Although many people always want to be up-to-date with the latest version, I am personally averse to making changes without some compelling reason. The maxim if it ain't broke, don't fix it applies; especially as the process of "fixing" it could break it, due to incompatibilities or other problems with the update. Many people still use HW4.2, in consideration of what more recent releases offer.

2.3 Other Pipe Organ Software

Hauptwerk remains the most capable virtual organ system. However, it is not the only act in town; the following other software can also be used to recreate a pipe organ:

GrandOrgue Creative Commons application based on Hauptwerk version 1.
Kontakt MIDI player that supports a significant number of third-party pipe organs.
Sweelinq Sampler produced by Noorlander, with over a dozen European organs included.
Great Organ Several cathedral and other organs by Digital VPO.
Modartt organteq Application with its own sounds modeled by additive synthesis.
EplayOrgan Offers a number of organs, plus MIDI editing facilities.
jOrgan Java-based virtual pipe organ application.
Aeolus Pipe organ synthesizer (VST plugin).
Miditzer Virtual Theatre organ with sounds generated by additive synthesis.
GigaStudio Streaming sample player by Tascam (support was ended in 2009).
Virtual Organ Can be played online for a subscription (the pipe organ is one of numerous instruments available).

Being based on Hauptwerk 1, GrandOrgue is the product most similar to Hauptwerk, and appears to be a viable low-budget alternative to it. A number of the earlier Hauptwerk sample sets are available for GrandOrgue; of particular note are those from Piotr Grabowski. However, the vast majority of Hauptwerk sample sets are for later versions of Hauptwerk only. A useful page from one of the developers of GrandOrgue is Lars Virtual Pipe Organs, on which can be found a number of free sample sets of Swedish organs.

2.4 Hauptwerk Sample Sets

With several hundred sample sets available, finding the right ones may be more daunting than choosing the virtual organ hardware. However, Hauptwerk comes with the St Annes, Moseley sample set.

2.4.1 General Criteria

The next section sampling discusses the technical criteria to consider when choosing a sample set.

Another area to consider is the user interface, and in particular what screens are available. All sample sets have a main console display with stop controls and keyboards. Other types of screen may include:

Stop and jamb screens may include photo-realistic left and right jamb displays, which may be in both landscape and portait formats. Many of the more recent sample sets also have a simplified stop layout screen, which is more compact and is likely to be easier to use than photo-realistic jamb displays.

Stop controls should include speaking stops, tremulants, and couplers. For both quality and performance, it is better to have recorded sample set tremulants than use the Hauptwerk tremulant model (which is used where nono are supplied). However, the supplied couplers might usefully be augmented by the Hauptwerk Master Couplers. The sample set controls may also include divisional and/or general pistons; however, these are not typically provided, as the Hauptwerk registration function (master pistons) renders them unnecessary.

In choosing a sample set, one should check that it is compatible with the version of Hauptwerk to be used. Many will work with Hauptwerk 4.2 and upwards (but often not 4.0); however, a number of sample sets require later versions. This information, together with RAM and other requirements, can be found on the producer's website.

Although the sample set for a small positive may be only a few hundred MB in size, a full load of a large organ with multiple channels can easily require more than 64 GB. A high-quality sample set of a given instrument will typically be larger than one of lower quality. However, other factors are involved; for example, dry sample sets are usually significantly smaller than wet ones.

Sample sets often provide function that is not available in the real pipe organ. Virtual organ software, in turn, may provide function not present in either the pipe organ or the sample set.

Some sample sets cost well over US$1000, some are completely free, while others require a donation to be made. In any case, donations are always welcome; producing a recorded sample set clearly involves a considerable amount of work.

2.4.2 Sampling

Although this section is based on Hauptwerk, the same quality criteria apply regardless of the virtual organ system used.

In good-quality sample sets, each note of each stop is normally recorded individually (so, for single-rank stops, each pipe). And there should be several recordings (samples) of each stop / note. This is to accurately model the three phases of each note played:

Attack
The initial transient (essentially the chiff produced when the pipe starts to speak).
Sustain
The sustained section (although uniform in principle, in practice it contains irregularities that impart naturalness).
Release
The end of the note (essentially reverberation, which may last several seconds).

The use of individual recordings of a real instrument eliminates issues with artificiality that affect electronic organs. However, each recording of the sustained section is only a sample of a few seconds; if the note is longer than this (as many notes on the organ are), the sample must be repeated for as long as necessary. As sustained notes are not perfectly uniform, this can result in repetition apparent to the listener. Another issue is that the effect of the reverberation depends on how long the note has been sustained.

To avoid the first artifact, good sample sets typically feature multiple recordings of the sustained sound of each pipe. These are known as loop samples, of which there may be several (often up to 12, sometimes even more). With longer notes, different loop samples of the pipe are used in a random sequence, thus removing any apparent repetition. This is particularly important for long sustained notes, which are most common in the pedals.

To provide more accurate reverberation, good sample sets include multiple release samples. There are typically three release samples for short, long, and medium-length notes (sometimes more). The Hauptwerk User Guide indicates that these have a greater effect on the sound than multiple loop samples, and having multiple releases is particularly important for clarity when playing short notes.

A few sample sets offer multiple attack samples (which also contain some sustained sound). There will probably not be enough to accurately model a tracker response in conjunction with a velocity-sensitive keyboard. However, there may be other benefits to realism. In general though, multiple attack samples are less important than multiple releases and multiple loops.

In practice, the number of attack/loop/release samples needed to achieve a given quality level varies. Good producers will use as many as they consider necessary to effectively remove audible artifacts. So it is not necessarily the case that a sample set with more such samples is better than one with fewer.

Many sample sets include recorded tremulants. Where not provided, they are modeled by Hauptwerk according to parameters in the Organ Definition File (in the same way as the swell box is modeled). However, this involves additional CPU load, and possible audio quality issues. But as providing a full set of recorded tremulants is likely to significantly increase the size and cost of the sample set, many offer only partial support.

Samples may be wet (recorded at some distance from the pipes to include the acoustic of the building), dry (recorded near the pipes, often inside the organ case), or semi-dry (or moist, or semi-wet). Most sample sets are wet, as the pipe organ can sound quite unpleasant without natural reverberation. However, dry sample sets are also available for use where there is already a lively acoustic, or with separate reverb (which is available in Hauptwerk). In a few cases, wetness is simulated by adding reverb to dry or semi-dry samples.

Samples are normally recorded in stereo pairs, but many sample sets offer multiple channels (more than two). These may comprise samples taken from the front and rear parts of the building, which be can be output by four speakers to give quadraphonic sound. Newer sample sets commonly feature three stereo pairs (six channels), or sometimes even more, recorded at different (close, middle, and far) positions. Apart from being used individually to give different natural perspectives, they are often mixed down to stereo to give different presentations. However, loading multiple channels considerably increases the RAM requirement.

In addition to recordings of the pipes, many sample sets include wind and action noises, to further enhance the realism. However, many interested only in making music may consider these to be extraneous. If there is no built-in option to disable these sounds, this can be done by simply excluding the relevant samples when the organ is loaded.

Recording quality of the samples should be at least CD (44.1 kHz with 16-bit samples), but is usually higher; often 48 kHz @ 24 bits. Moreover, the recording is often done at 96 kHz, to guard against degradation that may result from sample processing such as noise reduction. Although CD-quality is fine for the end result (tests have shown that SACD offers no discernible improvement), the extra resolution of the supplied samples over CD guards against any losses due to processing by Hauptwerk.

But in any case, other factors such as the microphones used, their placement, and any processing done on the samples are likely to have a much greater effect on sound quality than these technical parameters.

Each recorded sample contains the environmental background noise; for example, that of the blower. An adverse consequence of combining samples of individual pipes is that this background noise is cumulated for each sample involved in the registration. The greater the polyphony, the greater will be the summed noise level. It is therefore usual to apply noise reduction to the samples. Wind and any other required noise can be provided as separate sample(s); there will thus be only a single instance.

In many sample sets, not all samples are recorded; some are synthesized from the recorded ones. Where the real organ has a limited keyboard compass, it may be extended to that of a typical keyboard in this way. Many sample sets have one or more useful stops extra to the original organ that were synthesized from recorded stops. These enhancements can hardly be viewed as detrimental. Also, where the real organ has bad notes, it may be preferable to synthesize these from their neighbors. But in good sample sets, stops should be recorded chromatically; some compromise by not recording all notes of the scale.

While most sample sets feature only a single instrument, some are composite, meaning that they include samples taken from more than one instrument. Many of these are cheap or free, but require recorded samples from other producers (often free demos). This involves some compromise, partly as the samples will be from different acoustic environments. Nonetheless, this re-use of quality samples of known origin may be a good way to get a decent large instrument at low cost.

However, some producers offer composites that contain their own samples of unspecified origin, often at prices only somewhat lower than those of equivalent real single instruments. In the absence of clear information to the contrary, one should assume that such samples are synthesized rather than recorded, and therefore likely to deliver quality more like that of a digital organ than a virtual one.

2.4.3 List of Producers

This is a portal to all known Hauptwerk sample set producers, each with a summary of the instruments offered. It includes producers that are defunct, but whose products may nonetheless still be available somewhere.

To ease finding the most relevant producers, the list is broken down as follows:

Major Producers
Offer a significant number of original sample sets featuring instruments of different types.
Specialized Producers
Offer essentially one type of instrument (indicated in the description).
Minor Original Producers
Offer one or two originally-recorded instruments (enumerated in the description).
Composites Only
Made from third-party recorded samples, or own samples of unspecified origin.

The Contrebombarde Search page may seem to be a better way to find suitable sample sets, but if it were, I would simply have given this link. Apart from it often being difficult to specify appropriate search criteria, information on this site is likely to be incomplete, outdated, or otherwise inaccurate. More reliable information can be obtained by simply browsing the following list to get information from the horse's mouth.

For example, even though "Theatre organs" is a clear-cut category, a simple search on this returned only a single match; and that with a bad link to the producer website. But by browsing this list, one can easily find source information on 27 current Theatre organs from 3 producers, plus 4 no longer advertised.

Many producer websites have sound clips made using their sample sets. It may also be possible to find demo videos on youTube, and user-contributed sound clips on the Contrebombarde website.

KEY:
No producer website found.
Products are with another producer (noted), or cannot be found.
No new sample sets have been released for over five years.

2.4.3.1 Major Producers
Augustine's Virtual Organs About seventy original instruments, mainly from Hungary. Inexpensive, with some free (including a 51-stop Aeolian-Skinner). Also about a dozen composites, from either third-party or own (recorded) samples.
Hauptwerk NL About two dozen organs and a harpsichord, mainly Dutch, but also an Indonesian bamboo organ.
Inspired Acoustics Fifteen organs of a variety of styles, including some large symphonic organs.
Milan Digital Audio Ten organs (four Baroque, three Romantic, two Theatre, one American Classic).
OrganArtMedia Around two dozen organs, including many historical instruments, from several European countries.
Piotr Grabowski About thirty varied European organs. The earliest fourteen sample sets are free, and also for GrandOrgue. Friesach is perhaps the best completely-free sample set available.
Pipeloops Around twenty mainly German organs, with some French, and a steam calliope. Also completely-free sample sets.
Sonus Paradisi Around seventy varied organs, mostly European, but with some American. There are also harpsichords and other instruments. Most sample sets are also available in reduced versions as free demos.
Virtual Pipes Xport A number of old, but free or cheap sample sets, also available for GrandOrgue.
Voxus Virtual Organs Several historical organs, mainly Dutch, but also of other nationalities.
2.4.3.2 Specialized Producers
Andrea Bonzi Currently eight Italian instruments, with eight more in the pipeline, including harpsichords and a spinet, some free.
Binauralpipes Currently eight German organs recorded binaurally, including two not yet released.
CLR Resources Several American organs, now with Evensong.
Evensong About a dozen American organs, including those formerly available from CLR Resources.
Forestpipes Virtual Organs Seven German organs.
Jeux d'orgues Several free French historical organs for a variety of software as well as Hauptwerk and GrandOrgue.
Lavender Audio Seven English Romantic organs, including one composite.
Maltese Historic Pipe Organs Several Maltese historical organs.
Melotone Sound Productions Twenty Theatre organs, plus three church organs.
Organ Expressions Five American organs, including at least one composite.
Prospectum Currently nine historical German organs, including three in preparation, and two free.
Silver Octopus Over two dozen English Romantic organs, but many composites with samples of unspecified origin.
Somiere Maestro Three organs from Italy (Kaufman 2009, Biroldi 1838, Ninninger 1994).
Soni Musicae A few old but free harpsichords and other instruments (no organs).
Virtual Pipes Three Dutch organs (Walcker 1913, Gradussen 1887, Verschueren 1962).
Wustrow Organs Three German organs (Richborn 1681, Sauer 1991, Furtwängler & Hammer 1915).
2.4.3.3 Minor Original Producers
aH Virtual Pipe Organs St Stefanuskerk, Moerdijk (28-stop Marcussen neo-baroque).
Akkerorgels Reformed Church, De Pollen (8-stop Dutch positive by Bätz, 1766).
Appleton Audio Two English church organs in Australia (Neutral Bay, Penrith).
Audio Angelorum Peterborough Cathedral (85-stop English Romantic by William Hill), in 3 volumes.
Barritt Audio St Matthew, Cheltenham (39-stop English Romantic by Henry Willis). St David' Cathedral, Wales (Harrison & Harrison).
Beauty In Sound Romsey Abbey (37/49-stop English Romantic by J W Walker). St Mary, Redcliffe in production.
Christian Datzco Private Commission (5-stop positive by Dieter Ott, 2003). The first third-party Hauptwerk sample set.
Coral Pipes Bethesda Episcopal church (55-stop American Classic by Di Gennaro-Hart, 2007). Another coming soon.
Exemplum Organum St George's church, Ontario (42-stop Casavant).
Gerben van den Akker Two Dutch church organs (Mariënberg, Daarlerveen). Also a cornet (brass instrument)!
Legro Virtual Organ Bennekom (Cabinet organ by Onderhorst, 1762), free, also available for GrandOrgue.
Llanerch Organs Two English Romantic organs in Blackburn (the cathedral, St Silas' church).
Mark Beverley (Keith Spencer) Prudhoe Methodist church (9-stop English church organ).
Metrolina Theatre Organ Society Redford Theatre, Detroit (Barton), available from Melotone Sound Productions.
Michael Teske Grote kerk, Wildervank (Walcker 1913), available from Virtual Pipes.
MIDIPipeOrgan Two small Italian organs (Santa Maria degli Angeli, San Giovanni Battista).
Orgue de Pibrac Patrimoine de Pibrac (16-stop French organ).
Paul Delferriere French Harmonium (Debain, 1874).
Post Musical Instruments Post Positif Organ (2 ranks).
Sam Sleath - Sesquialtera Organs Two English organs (St Mary Downe, Mander Chamber 1982), plus composite reconstruction of Saint-Ouen in Rouen, plus three unreleased. Also Blackburn cathedral (available from Llanerch Organs).
Tarcisio Ferrari Two organs (Bellinzona G. Antegnati 1588, Vouvry Carlen 1822).
van der Waal van Dijk Hervormde kerk, Mijdrecht (23-stop Dutch Romantic by Bätz).
Virtual-Organs.nl Two Dutch church organs (Veendam, Oude Pekela). Also Walcker 1913 available from Virtual Pipes.
Zion Organ Two English church organs (Prudhoe, Penrith), now with Mark Beverley (Keith Spencer) and Appleton Audio.
2.4.3.4 Composites Only
Al Morse About twenty free composites, mainly based on sample sets from Sonus Paradisi and others.
Etcetera Pipe Organs Four composite organs (two American Classic, North European, Norwegian church) using own samples.
Haupterk-Organ.com Aristide (composite reconstruction of the Cavaillé-Coll organ of Saint-Ouen in Rouen). Also advertises sample sets fron Voxus Virtual Organs.
Key Media Productions Four composite Theatre organs by Neil Jensen (Connoisseur 3/35, 3/27, 3/19, 3/11).
Les Deutsch A number of free composites and extensions to original sample sets.
OBV Composite Baroque-inspired organ using Sonus Paradisi demos.
Organa Reginae Caeli Over two dozen composite reconstructions, requiring sample sets mainly from Sonus Paradisi.
Paramount Organ Works Five composite Theatre organs with samples from the USA and UK, including one free.

3 MIDI Devices

These form the front end of the system, being used primarily to handle the player's input into Hauptwerk. MIDI should not be confused with audio, which handles the output from Hauptwerk, and is thus at the other end of the chain.

MIDI devices used in virtual organs include the following:

The stack of manuals usually contains Thumb Pistons, except where generic keyboards are used. Most systems also have Expression Pedals and Toe Pistons. Some systems have physical Stop Controls, instead of (or perhaps in addition to) using a touchscreen. There may be Other Devices, which are most useful to support input and display where there is no accessible touchscreen.

Devices must be MIDI-enabled to work with Hauptwerk or other virtual organ software. Those from electronic organs built since the mid 1980s will probably already have MIDI. However, it will be necessary to MIDIfy devices from a pipe organ or old electronic organ, and this is likely to be practical only with pedalboards. But using parts from a decommissioned pipe organ or suitable electronic organ could potentially enable a high-quality system to be obtained at moderate cost, as these parts often sell for considerably less than what they would cost new.

Components designed for pipe organs offer excellent quality, but at a substantial price. On a real pipe organ, these items would account for only a small fraction of the total cost, so there would be little reason to economize on them. And pipe organs are designed to last perhaps hundreds of years. However, products for the consumer market are likely to be much less well built.

Compared to the popular music mainstream, devices for virtual organs occupy a niche market. The lack of competition results in little choice of consumer products, with high prices often being accompanied by poor construction quality. It is possible to pay prices approaching those of pipe organ components, for a much lesser standard. And the most widely-advertised and frequently-purchased products are not always (or even usually) the best!

3.1 Manuals

The keyboard stack is the most fundamental component in the system, and to a large degree determines its quality. And if it has specialized organ manuals, it is also likely to be the most expensive. Yet information on virtual organs from commercial vendors and others often makes no mention of the type of manuals they contain, preferring instead to focus on features that are evident in the photos.

Self-building manual keyboards would almost certainly not be feasible. And although used pipe organ manuals are available at attractive prices, re-purposing them would involve a substantial amount of work, and would probably be too difficult for most people. So they will usually either be bought new, or as part of a used ready-built system.

New organ manuals are expensive, costing upwards of US$500 or so for a single bare keyboard. On top of this, there will be substantial additional costs in mounting them into a stack of manuals with pistons and MIDI output. For this reason, many systems use considerably cheaper and more widely-available generic keyboards. However, they may not be satisfying to play, and have consumer-grade construction with a limited lifespan.

With their high cost, specialized organ manuals could reasonably be expected to last a lifetime (as indeed would those used in pipe organs). But most of those used in virtual organs have the same type of consumer-grade construction found in generic keyboards. These may last very few years before problems develop requiring specialized servicing and parts. When choosing virtual organ components, it always pays to look under the covers and think long term; and this especially applies to the manuals.

3.1.1 General Features

Specialized organ manuals differ from piano or generic keyboards in having a very slightly narrower scale. They are also designed to be built into a keyboard stack with mounting hardware, wood key cheeks, and rails into which pistons may be fitted. In addition, they will require electronics to enable them to be connected as MIDI devices. A generic keyboard will come complete in a case with a MIDI connector.

The traditional method of organ manual construction is wood-core, with long keysticks of wood, guide pins of metal, and bushings of felt or leather. These hand-made keyboards are clearly expensive to produce, but should last decades. They are in complete contrast to consumer-grade products, which are designed for low-cost mass production, and use internal parts of plastic and rubber. These will last only a few years, rather than decades.

Servicing of consumer-grade keyboards is likely to require inconvenient and expensive factory repairs that require special parts. Not only do wood-core manuals require much less frequent servicing, but being hand-assembled, are amenable to user servicing using readily-available materials and parts.

Wood-core keyboards are usually much more costly to purchase than consumer-grade ones. However, the latter are likely to work out more expensive in the long term, as they have a much shorter useful service life, and will require repairs with replacement parts every few years of use. The heavier the use, the greater the advantage in having wood cores.

While the action of the majority of consumer-grade keyboards would not please most organists, the action of a wood-core manual is unlikely to disappoint. It makes sense to pay ten times the price for a keyboard that lasts ten times as long as a consumer-grade one, especially when it is also better to play over that period! This argument applies to both wood-core organ manuals and mechanical computer keyboards.

Organ manuals may or may not come with key switches. In the pipe organ, the requirement depends on the type of key action; with mechanical action there will be only a connection to the tracker. The following are the main types that may be found:

Wire-and-Wiper This is the traditional type of switch for electric-action pipe organs and older electronic organs, having been around for over a century. Direct electrical contact is provided by self-cleaning wires. These may be covered in gold, and duplicated for redundancy and thus improved reliability.
Magnetic Reed An encapsulated switch (reed) is operated by a magnetic field, created by a magnet at the end of the key. There is thus no direct physical contact, and the lifetime should be at least 20 million switching operations (10 million key presses). However, it tends to be unreliable in manuals, mainly due to hysteresis. Also, as the magnetic field is diffuse, it may affect adjacent keys.
Optical Switching operates by detecting interruptions by the key to an infrared beam, which (unlike a magnetic field) can be aimed precisely. Being contactless and more reliable in manuals than the magnetic reed switch, it is potentially perhaps the best type of switch. However, it may be difficult to find.
Mechanical This type of contact switch (Cherry red) is used in high-quality computer keyboards for gaming. It has a silent and light action, and is rated at 5 million key presses. Although this is less than the lifespan of contactless switches, replacements for this ubiquitous product should be readily available.
Rubber Dome This is the type of contact switch used in consumer-grade keyboards (computer and musical). It forms part of a rubber membrane containing collapsing domes, each of which makes contact when compressed by its key. Switch lifespan is a fraction of that of mechanical switches. And if any switch becomes unusable, the whole membrane must be replaced. Moreover, being product-specific, a replacement may be difficult or impossible to obtain. The domes typically impart a spongy action. Its only virtue is low production cost (and perhaps further profits from sales of parts).

The compass of organ manuals is normally at most five complete octaves (61 keys), starting from C. This is the same range as have many generic keyboards. As new pipe organ manuals often have only 56 keys, it may be possible to economize by buying keyboards with a lesser compass; even 54 keys may be sufficient.

3.1.2 Available Brands

As these are very few, it is appropriate to discuss them individually.

The only three manufacturers of organ manuals are Fatar, Schwindler, and UHT. Another maker was Laukhuff, but this major organ part supplier sadly ceased trading in 2021. Moreover, only Schwindler and UHT make manuals with wood cores. This Hauptwerk Forum thread gives a good overview of these keyboards. For those on a low budget, there are numerous types of self-contained generic keyboard available at much lower cost.

Fatar manuals are by far the most common, and Fatar also makes keyboards used in digital pianos and synthesizers. Even though they sell for prices comparable to those of wood-core manuals, all Fatar manuals are consumer-grade, with moving parts of plastic and rubber.

Many people have reported that these parts wear out over a relatively short time period. Moreover, that these keyboards are not user-serviceable; and while replacement parts are available, they may take some time to obtain. The fourth post on this Organ Forum thread (from somebody who services organ manuals) explains very nicely why I would not buy Fatar manuals.

Yet they are used in most commercial ready-assembled organs, no doubt because they are the least expensive organ manuals available. And they are also widely sold separately under different names. The dichotomy of expensive wood-core manuals and generic consumer-grade keyboards has provided a lucrative niche, in which a mass-produced product that appears equivalent to a wood-core manual can sell for almost as much.

The action of a Fatar manual is generally considered to be decent, although of less than wood-core quality. However, it will deteriorate with wear, and will probably be unusable within a very few years of heavy use. There may be additional problems from a second strip of rubber domes used to simulate a tracker action (whether wanted or not). Those seeking a first-class action that will last a lifetime should read on...

Schwindler manuals are those used by PedaMidiKit, which I believe offers the most economical as well as the most convenient way to get a complete new MIDI keyboard stack with wood cores. And although the key spacing of my Schwindlers from PedaMidiKit is somewhat uneven, I am delighted with the action and feel; I cannot see how even UHT could be better here. See my experience of buying a keyboard stack from PedaMidiKit.

Although Schwindler has long made the lowest cost wood-core manuals, other people have concurred that they are very good to play. In my view, they are the clear choice for those on a medium budget, especially as they may be bought for not much more than the Fatars, and are likely to work out much cheaper in the long term. Schwindler, like both PedaMidiKit and Fatar, is Italian, even though it has a German name.

UHT manuals are high-end. They provide a great deal of function and flexibility, by all accounts also have an excellent action, and are no doubt better visually than the Schwindlers. Although much more expensive than the other two makes, they are likely to be the choice for those on a high budget.

Laukhuff manuals were intermediate in price between the Schwindlers and UHT. Although these three wood-core makes differ significantly in purchase price, there seems to be little to choose between them in their action and durability; all are excellent.

3.1.3 Special Features

Both UHT and Schwindler make keyboards that simulate tracker action by using magnets. PedaMidiKit offers Schwindler manuals with two types of tracker action, in addition to the standard (electric) action. With UHT, the tracker action is adjustable. All Fatar classical organ manuals have a light tracker action (SNAP function) implemented by rubber domes that can split and cause loud pops (this is presumably the undocumented "POP function"😋). I have a sneaky suspicion that Fatar imposes this initial resistance to disguise sponginess in the rubber dome key switches!

Note that the ability to control the chiff would require both velocity-sensitive keyboards, and a sample set with multiple attack samples (which very few have, and those few do not have enough to properly model tracker action). A velocity-sensitive keyboard may also be needed to control second touch for theatre organs (although the sample sets I have seen provide other means of doing this). Otherwise, this feature is superfluous for a pipe organ.

The standard type of key covering is plastic (acrylic) with black sharps on white naturals. Another common style is black naturals with light wood sharps. These are the two types of keytop offered by Fatar, in distinct models (some people appear to believe that the more expensive latter models have wood cores!). Makers of wood-core manuals (which are made to order, not mass-produced) offer numerous other options in various materials for all models, and also offer various shapes of sharp and key front.

Keytops made of natural materials may have a classier look and a pleasanter feel; however, being porous they will absorb sweat and oil from the fingers. Plastic coverings are inherently cleaner, but their smooth surfaces may be slippery; a more suitable surface may be obtained by a light sanding with 600 grit sandpaper.

3.2 Pedalboard

Unlike manuals, used pedalboards from pipe organs are often MIDIfied for use with a virtual organ. Pedalboards can also be obtained from electronic organs (with or without MIDI). It is even possible for a dedicated and well-equipped DIYer to build a pedalboard from scratch (the link is to one of several pages that describe how to do this). So there are more ways to get a pedalboard than a set of manuals.

Although building organ manuals is specialized and there are few suppliers, many new pedalboards on sale are made in-house, as they are relatively easy to build. But some popular pedalboards on the market appear to be made of soft pine, or are otherwise of questionable construction - see this Hauptwerk Forum Post. Again, there are consumer products with price tags close to those of pipe organ pedalboards, but built to consumer standards. For those with limited funds who put construction and playing quality before pretty veneer and fancy electronics, I believe that PedaMidiKit again offers the best deal; see my experience of buying a pedalboard, and my review of the result.

A pedalboard for serious use should be to AGO or BDO standard. It should thus be concave, with either 30 (BDO) or 32 (AGO and BDO) pedals. But for those on a low budget, a 30-note flat pedalboard may be acceptable, especially if no other pedalboard will be played.

A concave pedalboard is generally preferable to a flat one, as the outer pedals are easier to reach, being more elevated than those in the middle. However, a concave design is significantly more costly and more difficult to build. Hence low-cost pedalboards are usually flat, and thus do not comply with AGO or BDO standards.

While 30 pedals are required even for baroque music, very little music requires 32. But with the standard alignment of manuals and pedals (middle D over middle D), a 32-note pedalboard is centered on the manuals and console, while a 30-note pedalboard will be somewhat off-center. Apart from being more esthetically pleasing, having everything centered tends to ease console layout. A pedalboard with fewer than 30 notes is not suitable for general use; many from electronic organs have only 25. And one can hardly add more pedals later!

The choice of parallel (BDO) or radial (AGO and BDO) pedals is likely to depend largely on one's geographical region; radial pedalboards are the norm in the USA and the UK, while parallel ones prevail in Europe. Personal preference may also be a factor; radial pedals correspond more to the natural angle of the feet, but with spacing that varies from heel to toe end. As a radial pedalboard is narrower at the heel end than a parallel one, the bench can have a smaller span. Radial designs also tend to be more expensive to buy and more difficult to build than parallel ones.

In any case, there should be standard spacing between the pedals. There are many compact pedalboards from electronic organs that have nonstandard spacing that is unsuitable for playing elaborate pedal parts. For example, the distance between the naturals must be constant, regardless of whether there is an intermediate sharp.

There are two methods of springing; wire toe springs, and sprung metal heel plates. For the best action, both should be used, with light springing at the heel. Where there is only one type, it is better to have wire toe springs, as it is difficult to achieve the required resistance and good stability by fixing at the heel end only. The AGO standard specifies 2.5 to 3.0 pounds of resistance and 0.5" depth of touch at the heel end of the sharps; many consumer pedalboards are deficient in either or both of these criteria. The action should be firm (not floppy), without significant lateral movement.

A MIDIfied pedalboard will normally use magnetic reed switches. These do not cause the same reliability problems as in manuals, as pedals have both greater depth of touch and wider lateral spacing. The switches may be encapsulated in glass or plastic; the latter is less likely to fracture on impact.

A rechargeable and dimmable pedalboard light with motion sensor is likely to be desirable (and perhaps also a similar type of light over the manuals). A single unit about 9" (23cm) long mounted under the desk surface should give a good light over the entire area of the pedalboard.

3.3 Thumb Pistons

This is a stub. As I bought a ready-assembled stack of manuals, I have done no serious investigation. But this did require consideration of the question How Many Pistons?, especially given their inordinate cost.

3.4 Toe Pistons

This is a stub. As I never had any intention of buying these with the first-time system, I have done no investigation.

3.5 Expression Pedals

This is a stub. As I never had any intention of buying these with the first-time system, I have done no investigation. However, the section How Many Expression Pedals? may be of some use.

3.6 Stop Controls

As I have no experience of buying or using these, I offer only general comments in this section.

While stop controls are typically operated via touchscreens, some virtual organs use physical MIDI drawknobs and/or tabs. These are likely to be expensive, especially with a combination action in which they are moved by pistons. But they can make a virtual organ look and feel just like a real pipe organ console. Real organists will prefer handling them to poking a touchscreen, and they are also more attractive esthetically. As such, they may be considered essential by many professional organists.

However, apart from being cheaper and easier to implement, a touchscreen offers much greater flexibility. In particular, a physical stop control layout is based on one specific organ, and will not fit well with other organs. This limitation can be addressed by providing spare stop controls and relabeling; however, this makes changing from one sample set to another much less convenient than with a touchscreen.

A touchscreen may also be used for many other functions, and for displaying information. If there is no easily-accessible touchscreen, consideration must be given as to how to supply the required function. This includes both user input via controls, and output via displays.

As use of physical stop controls requires more much investigation as well as being more expensive, a self-assembled first-time virtual organ would probably best incorporate a touchscreen. This could subsequently be replaced by MIDI controls, in consideration of the experience gained to date.

Many systems feature both touchscreens and physical stop controls. Touchscreens would typically be used for speaking stops; as these differ with each organ, implementation with physical controls is inconvenient. But accessory stops like couplers might be implemented with physical tabs that operate the Hauptwerk Master Couplers.

3.7 Other Devices

These are particularly useful for input and output in place of a touchscreen.

The Novation Launchpad features a set of buttons that can be assigned functions as required. Different functions can be assigned for different organs, and multiple units may be used.

Hauptwerk can output various types of status information through 32-character (two-line) LCD panels. A console would normally incorporate several of these to support display of all important information.

3.8 Connecting MIDI

This section is intended only to give an idea of how to connect ready-built MIDI components to the Hauptwerk computer. It does not deal with assembling such units.

Connection of MIDI devices is usually via either a MIDI cable with 5-pin DIN plugs, or USB (MIDI over USB). Wireless connection over Bluetooth is also possible, but not recommended due to the excessive latency. PCs have native MIDI drivers provided by Microsoft, but do not normally have DIN sockets to support plain MIDI connection.

However, most recent MIDI devices offer a direct USB connection, which should be used in preference to DIN. MIDI over USB eliminates the need for both a separate power supply, and connection through a MIDI interface, without significant drawbacks. USB hubs can be used to increase the number of ports (with the usual proviso of using self-powered hubs where the devices involved draw more than a modicum of current).

Connection of devices with DIN plugs must be done via an interface, which will usually connect to a USB port. But as many audio interfaces offer MIDI connectors, a separate MIDI interface may nonetheless not be needed.

Each MIDI connection to the computer (including via a USB hub) is associated with a MIDI port. There will typically be a MIDI port for the pedalboard, another for the complete keyboard stack (including thumb pistons), and perhaps others for expression pedals and toe pistons. However, in some cases, separate ports may be used (for example, with separate generic keyboards). In other cases, they may be combined into a single port via an interface.

A MIDI channel number (1 to 16) is used to differentiate devices within a MIDI port. Each keyboard (pedalboard, and each manual) §must be assigned a unique channel number. Thumb pistons will normally be asigned another channel number. To avoid conflicts, it may be necessary to change the default channel numbers before connection (for example, one should check that the channel number of the pedalboard is not the same as that of a manual or the pistons).

Each control (for example, key or piston) within a MIDI channel is identified by a MIDI Note number. This is a value from 0 to 127, which forms part of the MIDI message. For keys, a MIDI ON message with the MIDI note number is sent when a key is depressed, and a MIDI OFF message is sent when a key is released. Continuous controls such as expression pedals instead send MIDI Control Change messages.

A §stuck note occurs when a MIDI ON message is received without a corresponding MIDI OFF message. This is likely to originate from the MIDI device itself; for example, a speech point set too low, or from not fully depressing the key. It can usually be cleared by pressing the key again (so that another MIDI OFF message is sent); failing this, there is a facility in Haupwerk to clear all MIDI messages.

Before connecting MIDI devices, one should check the Hauptwerk MIDI issues that I have encountered. Awareness of these can avoid problems with MIDI devices (apparently) not being recognized.

4 Computer System

For best performance and reliability, the computer should be dedicated to Hauptwerk plus any auxiliary applications (such as a metronome), and purged of anything not required for this purpose.

It should never be connected to the internet, nor should there be any other external connectivity, except to direct RF-connected devices such as a mouse, keyboard, and (possibly) headphones.

4.1 Overview

Apart from a box with CPU, RAM, and secondary storage (SSD / HDD), the computer system should have the following:

A big advantage of getting a PC rather than a Mac is the much greater (but still hardly impressive) choice of hardware, at more moderate prices. I originally intended to buy a Mac for my Hauptwerk system, but the only model that met my requirements was the Mac Pro, which started at over US$6,000! The downside of using Hauptwerk on a PC is Microsoft Windows TM, but one can minimize its insidious nastiness by taking heed of the hints given in this section.

For the most flexible and ergonomic console layout, one should buy a box with separate input (mouse, keyboard) and output (touchscreens, etc.) devices. While a laptop may well provide plenty of processing power, it will have a significantly less favorable price/performance ratio than separate components. An all-in-one is more cost-efficient and has a separate keyboard, but as with a laptop, the built-in screen compromises console layout. For most systems, a mini PC that one can leave running 24/7 may be the best option.

4.2 The CPU

Especially with the issues in powering the computer on and off, 24/7 operation is highly desirable. However, it may not be reasonable with a power-hungry processor, especially since the operation of Hauptwerk is hardly energy-efficient.

4.2.1 Polyphony

The maximum polyphony that can be achieved is determined primarily by the processing power of the CPU. For faultless sample processing, the required polyphony must not exceed this maximum.

The maximum (static) polyphony can be found experimentally and set in Hauptwerk. It depends not only on the computer performance (CPU, cacheing, and RAM), but also settings such as the audio buffer size and sample rate, and any additional Hauptwerk processing such as real-time reverb and changing organ pitch. For example, changing the audio sample rate from the usual 48 kHz to 96 kHz halves the available polypyhony. Therefore the test should be applied with these settings. Performance may also be seriously degraded by other applications that that are running (or may be started unexpectedly).

Unfortunately, the required (dynamic) polyphony cannot be determined in advance. There are obviously considerable dynamic variations that depend on the stops drawn and keys depressed. But polyphony is not simply a function of the number of pipes that speak simultaneously, as this does not take into account release samples (the reverberation once the pipe has stopped speaking). These are likely to occupy a large proportion of the polyphony.

Playing many notes in quick succession substantially increases the polyphony, as while the loop parts of the samples are short, each has a release tail that typically lasts several seconds. Playing several notes simultaneously obviously also increases the polyphony; however, one would not normally play several fat chords per second as with individual notes. Dry sample sets not only occupy much less RAM, but also have short release samples that reduce the dynamic polyphony; however, they require added reverb to produce acceptable sound in a normal room.

If the dynamic polyphony exceeds the preset static polyphony, normally the only consequence is that release samples are dropped early, resulting in a drier sound. The required polyphony can also be reduced in advance by specifying truncation of release samples when loading the sample set; this is likely to make the biggest difference with fast-moving music.

The Hauptwerk documentation indicates that it would take a substantial insufficiency to cause complete loss of stops. CPU-related glitches are likely to be caused by unwanted activity, such as Windows deciding to do a virus scan during a particularly involved tutti. This results in the preset static polyphony being too high, thus inhibiting management by Hauptwerk. Hence the importance of computer preparation to avoid unnecessary processing.

Note that latency is a function of the audio interface, not the CPU; it has nothing to do with sample processing. However, setting a low latency may significantly reduce the available polyphony, or cause audio glitches.

4.2.2 Practical Considerations

The usual advice is to buy the fastest processor possible. This is only reasonable if having the maximum possible processing headroom overrides all the following:

But unfortunately, the Hauptwerk documentation implies that anything other than a top-end Intel processor is substandard. And the Hauptwerk website currently recommends only an Intel i9 Core for a PC. This will have misled many people into buying a system with a power consumption comparable to that of an old toaster, when a far more economical and efficient one would have worked just as well.

The criterion in a real-time system such as Hauptwerk is sufficiency; a faster processor is only better in situations where a slower one cannot achieve the required polyphony. And even then, there are normally only minor consequences. Using a processor whose capacity is not utilized is simply wasteful. This is especially the case with the diminishing returns that apply at the leading edge; just a few percent extra performance adds substantial cost and power consumption. And with the wide range of possible processing requirements, this would rarely make a material difference.

So rather than just accept that only a high-end Intel will do, the purchaser should consider carefully what processor will meet their requirements. Detailed information that should give a good idea of what level of performance is appropriate can be downloaded here. Due to overheads in polling MIDI devices, I would not in any case recommend a two-bit processor for Hauptwerk (a 64-bit one is definitely a good idea!). But a blanket recommendation to get an Intel i9 Core is clearly NOT appropriate.

The good news is the development of mini PCs with processors of surprisingly-high performance that consume surprisingly-little power, and which require no fan in a very small box. I believe a unit of this type with 8 cores and a high clock rate (around 3.6 GHz) will function flawlessly for the vast majority of users.

And with this type of computer, it is reasonable to leave the system running 24/7. This makes the organ immediately available at any time, and obviates the issues with turning the system on and off. However, this is unlikely to be attractive with the likes of an Intel i9 Core, especially since Hauptwerk actively executes continuously without user input, and does not support any power saving modes.

4.3 Primary Storage (RAM)

Hauptwerk is a RAM-based system; the entire sample set data (or a selected subset) is loaded into memory before the organ can be used. This results in a high RAM requirement, but streaming the data would result in access delays that are unacceptable in a real-time system. If there is insufficient RAM, the sample set will simply fail to load.

So, unlike the required polyphony, the RAM requirement is static and predetermined. Most sample set suppliers provide it in their specifications, and there are usually various options for reducing the full requirement. These include reducing the audio quality of the samples, and loading only a selection of the samples.

Many recent sample sets feature 6 or more channels, which may all be loaded into memory and mixed down to stereo. This will considerably increase memory requirements. With 6 channels, only a fairly small organ can be loaded into memory if the RAM capacity is 32 GB; at least 64 GB will be required, or even 128 GB. On the other hand, with only 2 channels for normal stereo, a large organ can be loaded into 32 GB with high-quality samples.

4.4 Secondary Storage (SSD / HDD)

For many years, the Hard Disk Drive (HDD) has reigned. However, it is now being largely superceded by the Solid State Drive (SDD), which is continuing to fall in price and increase in capacity. In a new computer, the storage unit on which Windows is installed is likely to be an SSD.

An SSD offers considerably better performance (in practice, limited by the interface - SATA is relatively slow). It is also in general more robust and reliable. However, there is a limit to the amount of data that can be written to the SSD before it becomes unreliable.

There are different types of SSD with significantly different durability characteristics, but in any case the write durability increases with the amount of free space on the SSD. One should therefore have plenty of spare capacity on the unit, especially one to which a lot of data is written. But if the SSD is used essentially read-only, it can be filled fuller and still have a longer lifespan than an HDD.

I find external storage connected via USB to be a better way to store data such as sample sets than placing it on the unit that comes with the computer (on which Windows is installed). With the latest USB standards (3.1+), performance is excellent (better than SATA), and being able to dismount the storage means that it can easily be used elsewhere, or replaced if it becomes insufficient. And this maximizes the free space on the internal SSD (and thus its lifespan).

Hauptwerk requires all installed sample sets to be in the same base directory (in other words, on the same storage unit), and it is difficult to know in advance how much space might be required. However, if it is located on external storage, it is easy to replace the unit with a higher-capacity one if it becomes necessary. Naturally, as loading sample sets is data-bound and time-consuming, it is much better to use an SSD for this purpose. But as adding sample sets is write-once, the SSD can be filled to a high proportion of its capacity.

4.5 Turning the System On and Off

While straightforward with a digital organ, the issues associated with this may seriously impede use of a Windows-based virtual organ.

The most convenient way to turn the system off and on is hibernation; this restores the desktop, and takes only a few seconds with an SSD. However, it writes the entire RAM contents to the storage unit on which Windows resides (the file C:\hiberfil.sys). As this will nowadays normally be an SSD, hibernating on more than an occasional basis may considerably reduce its lifespan, as explained above.

Serious organists may want to practice several times a day. With the large amount of memory occupied by a sample set, hibernating this frequently could result in errors on the SSD well within a year. And Microsoft does not permit relocating the hibernate file. As a result, the complete system may soon become unusable, resulting in the purchase of another system and another copy of Windows (just what Microsoft wants!).

Moreover, the Hauptwerk User Guide does not recommend hibernation or any power-saving modes. In fact the computer has hibernated without problems for me the very few times I have used it. But Hauptwerk executes continuously (at least while an organ is loaded); this precludes both Sleep mode and a processor-specific power-saving mode.

And the Microsoft-recommended and default "fast startup" is another product of the Microsoft Dirty Tricks Department. Most users are not aware that this also writes the RAM to the hibernate file. Moreover, it does not clear out any system gremlins, as the user would expect; nor does it restore the desktop. So it is pretty much useless from a user perspective (but great for Microsoft!), and should be disabled by unchecking the following:

Control Panel -> Hardware and Sound -> Power Options -> System Settings -> Turn on fast startup (recommended)

If this is grayed out (as is probable), it is necessary to click "Change settings that are currently unavailable" - another Microsoft gotcha - I admit that I was stumped for a while!

But either type of shut down means that everything will have to be started up again (including Hauptwerk, and loading the sample set). This will take much longer than the Windows startup time on an SSD (so "fast startup" offers little practical benefit, only the serious disadvantages of reducing the SSD lifespan and failing to clear out the memory).

So, what to do? One approach is to hibernate (if it works OK), but buy a spare SSD when you buy the computer, and clone to it the SSD on which Windows is installed. You can then use it to replace the original when it becomes defective. If you do this, keep the additional SSD connected to the power (for example via a USB converter), as data retention of SSD is highly questionable without a power supply.

All this makes clear the importance of buying a system that can be left running 24/7. This also allows practice at odd moments, and the lack of power on/off cycles maximizes system longevity. But I for one would not want 24/7 operation with the only type of processor recommended by Milan Digital Audio.

4.6 Computer Preparation

One unfortunately cannot completely escape the lamentable fact that a virtual organ is a PC running Windows, whose abysmal standards reflect that it has perhaps the ultimate captive market. However, the adverse consequences of this can be minimized by appropriate preparation. This primarily involves removing, disabling, or disconnecting anything that is not necessary for the execution of Hauptwerk, thus maximizing the likelihood that the system will function efficiently and reliably. This is a more practical way to prevent glitches than purchasing an over-the-top CPU.

As will be seen, Microsoft does not make this easy, partly due to the monstrous dog's dinner that is the Windows user interface. However, I believe that the time spent on the following steps is a good investment.

Microsoft Windows TM 10

4.6.1 Do NOT Connect to the Internet !

As from Windows 10, this is the only way to escape Windows Updates, which apart from being a gross inconvenience, can (and do) change the behavior of your computer and deposit crapware without your knowledge or consent. Without an internet connection, you can confidently remove or disable a boatload of humongous impedimenta that Microsoft installs and executes on your computer, again without your knowledge or consent. The PC you paid for will no longer be effectively owned and operated by Microsoft.

Microsoft clearly does not like you using Windows without an internet connection, as then they cannot conduct cell searches (spy on you), or carry out lockdowns (known as "updates"). You are forced to setup Windows 11 with a Microsoft Account, which requires an internet connection. You are also required to provide an email address (give them one that you do not normally use).

However, the current Microsoft Service Agreement allows Windows 10 or 11 to be used indefinitely without an internet connection. This might nonetheless change with a future update; remember there was never going to be a Windows 11. Even offline, there will still be tiresome internet-related nag messages for a while. Thankfully, they appear to go away altogether after a few weeks offline; then you will not just be on parole, but completely free 😊.

Microsoft Windows TM 11

4.6.1.1 iLok Licensing

Hauptwerk licensing without an internet connection requires purchase of an iLok USB dongle. While it may be unpalatable to pay for a product that benefits MDA not yourself, the dongle permanently frees you from licensing issues, and will continue to work in the event of internet connection problems. It may also be used to license the same product(s) on more than one computer (Windows or Mac).

Initialization of the dongle for Hauptwerk should be done on another computer with an internet connection. This computer should also be used to update the dongle, as required for Hauptwerk updates and to use commercial sample sets. In order to install a Hauptwerk update, the old version must first be removed from the list of iLok-installed products (this does not apply if one pays for a complete new product).

4.6.2 Use the Administrator Account

You can start Windows offline with the Microsoft Account (if you value your privacy, never use it to login online!). However, unless you really want to have to key in a PIN, and be denied full use of your computer, I recommend restoring the Administrator account (this was once the default account, but has long since been hidden from you). Key in the following at a command prompt (run as Administrator):

net user administrator /active:yes

On restarting the computer, the default account is Administrator, with no password required.

If the above does not work, do a Google search to find other ways.

4.6.3 Disable Virtual Memory

Virtual memory (put simply) is the use of secondary storage to extend physical RAM into a virtualized address space. This involves swapping pages of memory between secondary and primary storage. At one time, this was a useful way to get around problems with insufficient RAM, but is nowadays of questionable value.

For Hauptwerk, there should always be sufficient physical RAM installed; as previously noted, the RAM requirement of Hauptwerk is (essentially) static. Virtual memory is then redundant, and likely to be detrimental. Swapping onto an HDD will result in performance issues unacceptable in a real-time system. Swapping onto an SSD will reduce its lifespan.

Open the Virtual Memory window as follows:

  1. Open Settings by clicking on the cog in the taskbar
  2. Click on System
  3. Click on About; in the left-hand pane
  4. Click on Advanced system settings (near the bottom of the window)
  5. In the System Properties window, click the Advanced tab
  6. Click on Settings... in the Performance groupbox
  7. In the Performance Options window, click the Advanced tab
  8. Click Change... in the Virtual memory groupbox

The above is the shortest route I can find; and the search facility cannot find Virtual Memory.

In the Virtual Memory window, uncheck Automatically manage paging file size for all drives. Then select each drive in the list in turn, and click on the No paging file radiobutton. When all done, click on OK.

4.6.4 Disable Unwanted Functions

The following optimizations give only a suggestion of some areas to check, based on my own preparation. It may be a good idea to review other settings. Another place to look is the Registry Editor, but this should only be used by those who know what they are doing!

Group Policy Editor

Open using Windows Key + R and type gpedit.msc. Navigate to the following:

Computer Configuration -> Administrative Templates -> Windows Components

There may be other settings here that are worth checking out.

Control Panel

Open Control Panel (enter Control Panel in the task bar search box). In the Control Panel search box, key Turn windows features on or off.

Disable any that appear to be unnecessary, including:

Settings

Open by clicking on the cog in the taskbar:

Services

Open the Services applet (enter Services in the task bar search box). Go through all services, and set to Disabled or Manual startup where appropriate (and possible).

5 Audio Devices

Audio has nothing to do with MIDI, even though these two areas are often discussed together. However, many audio interfaces offer 5-pin DIN connectors for MIDI devices.

Although PCs normally come with audio support, Hauptwerk calls for better quality than would be used for sonic wallpaper while playing with the computer. So high-quallity audio devices should be purchased as part of the virtual organ.

5.1 Audio Interface

The Hauptwerk User Guide describes the audio interface as perhaps the most crucial component in the system. Apart from determining the usable audio latency, it can also have a significant effect on polyphony. And it is much more economical in both purchase price and power consumption than a computer system with a high-end CPU.

For Windows, a high-grade audio interface with ASIO driver is essential for low latency and high sound quality. Lower-cost audio products use the Windows DirectSound driver, which is to be avoided. There is a freeware ASIO driver ASIO4All that may enable acceptable performance to be obtained from the PC's audio output or other consumer-grade audio hardware in the absence of any specific ASIO driver.

The usual means of connection is via USB. Two other connection types are AVB and Thunderbolt, but these are not typically supported natively by the PC, and for most people will offer no real advantages over USB. Many audio interfaces have MIDI input and output connectors that may obviate the need for a separate MIDI interface.

A high-quality 2-channel interface (for normal stereo output) can be bought for around US$200. This is appropriate if only headphones or stereo with 2 speakers will be used. To drive more speakers for surround sound, the number of output channels must be increased accordingly. For a given quality level, this will considerably increase the cost of the unit. Except for AVB interfaces, it is not normally possible to combine units to provide additional channels.

I consider the ability to monitor levels via a color LCD display to be essential; yet very few units seem to have good (or even any) level indication. A number of people have reported clicks and crackles that are clearly audio clipping; this can be avoided by simply monitoring the output level, and adjusting it as necessary (one should go into the yellow zone on peaks, but never into the red). The "Audio, MIDI and Performance" control panel allows the audio output level to be adjusted, but it is better assessed on the audio interface unit.

5.1.1 Latency

Latency in a virtual organ is the delay between §pressing a key and §§sound being produced. For listening to music, latency is not an issue; however, it may lead to an unacceptably poor response when playing a musical instrument.

Normally, most of the latency in a virtual organ is due to the audio interface and its driver. Nonetheless, a good-quality ASIO device should not introduce noticeable latency. There is also latency in polling MIDI devices, but this is very low (of the order of 1 ms). Bluetooth headphones can introduce considerable latency, so are not recommended. Insufficient CPU performance does NOT cause latency (at least not in Hauptwerk).

Audio interface latency is directly dependent on the audio buffer size. This is measured in sample frames, and is normally a power of two. The buffer size and other audio parameters may be adjusted in Hauptwerk, although it may be necessary to open the device control window. Halving the buffer size halves the latency, but this also increases the CPU load, and may seriously compromise performance and reliability.

With a good-quality ASIO interface, a suitable initial value is 1024, with a corresponding latency of around 24 ms (or about 1/40 s). This can be reduced to as low as 128, giving a latency of around 3 ms. However, even if this seems to work OK, it will come at some cost in significantly reducing maximum polyphony, and the likelihood of audio glitches.

A more reasonable goal than zero latency is zero perceptible latency. Beyond this, reduction in buffer size will be of no practical benefit, and may lead to problems that are very obvious. I do not notice any latency even with the default of 1024 (24 ms), but with a high-quality audio interface there should be no harm in reducing it to 512 (12 ms). However, I would be cautious about reducing it further, especially with a CPU of modest performance.

In any case, much greater latency may be experienced when playing a real pipe organ. Although there is normally little latency from the action, sound from the pipes may take a significant length of time to reach the organist. For example, pipes just 15m (50') from the console result in latency of about 45 ms.

5.2 Headphones / Speakers

In my opinion, a comfortable pair of headphones is preferable to speakers for individual use, especially for practicing. Those at around US$250 can give better sound quality than all but the very best speaker systems costing many thousands of dollars. And this is not compromised by room interactions. The result is a better ability to discern defects in one's playing. Although headphones are not capable of tactile bass, they can give a better impression of deep pedal notes than most speaker systems.

Open-backed headphones give rather more transparent sound. However, closed-back ones may be preferable where there are high ambient noise levels, or the noise produced by the headphones may disturb people around. High-impedance headphones tend to give the best sound quality, but the audio interface may not give sufficient output to drive them, thus requiring the use of a headphone amplifier.

Wireless headphones are unlikely to offer the same sound quality as a good wired headphone. But if used, they should have direct RF communication; Bluetooth headphones are known to introduce substantial latency, due to the additional encoding and decoding.

Speakers used with a virtual organ will probably be small nearfield monitors (probably not of very good quality), and will need a subwoofer to get anything like the bass response needed for deep pedal notes. Although they can give surround sound, this is likely to be inconvenient, and placement and matching issues make it difficult to achieve good results. In any case, the quality of output from speakers is highly dependent on their positioning and the properties of the room. They are usually placed against walls, which increases bass output, but seriously compromises sound quality in general.

Nonetheless, especially in a small and acoustically dead room, surround sound through multiple speakers may provide a welcome sense of spaciousness. But the best type of surround sound is available through headphones via binaural recording; this gives a more accurate sense of space than any number of speakers. And a large proportion of Hauptwerk users listen through headphones. So how about some more binaural sample sets? The signal fed to the headphones could cross over to a subwoofer at say 50 to 100 Hz, to give tactile bass as well as superb imaging.

6 Getting a Virtual Organ

The aim of this section is to give the prospective purchaser of a virtual organ an overview of the many different paths one can take, and some of the pitfalls.

Buying a virtual organ is hardly like buying a TV. You will not be able to visit your local virtual organ showroom to try out the range of pedalboards they have on offer, or even see such information as reviews. It is also likely to require a significant financial outlay, comparable to the cost of a car. Hence the importance of proper investigation and research.

A virtual organ requires the following components:

These components can be purchased as a complete turnkey console, obtained separately and assembled with a plain table, or anything in between. So the following criteria should be considered:

Assembly Type
Complete Turnkey, Computer-ready, or User-assembled from separate components
Furniture Type
Console (usually with jambs), Desk (surface without jambs), or Table (with four legs)

The key components (pun intended) are the manuals and pedalboard. The information in these links is important not only for those buying them as separate components, but also those contemplating buying a ready-assembled system.

Another basic decision is whether to use touchscreen(s) or physical stop controls (or possibly both). Most systems use touchscreens, as this is both cheaper and easier to implement. But some systems effectively emulate a real pipe organ console.

The section Budget Systems discusses just what manuals and pistons are really needed. And a considerable amount can be saved by buying used components and re-purposing them.

6.1 Assembly Types

A virtual organ may be obtained in the following three forms:

Complete Turnkey
Complete system, ready to run.
Computer-ready
As a turnkey system, but requiring a computer system with touchscreens and audio devices.
User-assembled
Built by the user from MIDI devices, furniture, and a computer system.

Products that include a console or desk tend to be significantly more expensive than the value of the components involved. One cannot expect the same quality in a consumer product built down to a price as one would find in a pipe organ. And it may not be possible to choose the main components, nor determine their origin.

Such products will typically be purchased only on the basis of information on the internet. Instead of high component quality and robustness, the emphasis will be on putting checks in boxes and an attractive appearance. Where no information is given about the manuals, it is reasonable to assume that they are made by Fatar. A ready-built product is therefore something of a pig in a poke.

Nonetheless, such systems will appeal to many who have the money, as they are easy to purchase, and a presentable console with attractive furniture might otherwise be difficult to obtain.

6.1.1 Complete Turnkey

This comes with a computer with installed software, usually with touchscreens and speakers fitted in a full console. Some of these are tall cabinet designs that incorporate all functions in as little floor space as possible. A turnkey system offers the greatest ease of purchase and installation, but at the same time the fewest options and least flexibility.

While the built-in touchscreens may be convenient, they tend to be small and limit the way in which the software can be used. And even these systems cannot completely hide the fact that underneath is a general-purpose computer.

Being installed in a console will normally mean that touchscreens and speakers are in fixed positions. And although many consoles offer surround sound, the speakers themselves may not be of particularly good quality, as well as being compromised by placement in a console. However, some systems come with free-standing speakers (although these are also likely to be mediocre).

As virtual organs have now been around for many years, it may be possible to get a used ready-to-run system at a moderate cost. This might have been obtained in any of the ways given here; for example, there must be many digital organs that have been converted to Hauptwerk.

6.1.2 Computer-ready

This includes the MIDI devices and furniture only, normally with a desk. New systems will probably include a compartment and fittings for installation of a computer. They will typically be from the same companies that produce turnkey products or digital organs. They are mainly targeted at the home consumer, and sold off the internet. As such, like turnkey products, they will be made to look attractive, but one should check out component and general construction quality.

An alternative to buying a ready-built unit may be to get an organ console and MIDI devices custom built by a company that builds virtual organs to order, or by a supplier of consoles to organ builders. Apart from the ability to specify the design (perhaps based on a real organ), it should offer excellent construction quality (but will not be cheap). It will also require a lot of interaction, and ideally one should visit the workshop several times to check the work.

Another possibility in this category would be to buy a used electronic organ, if it has MIDI outputs. However, the quality and suitability of the components should be carefully checked; for example, that the pedalboard has at least 30 notes.

6.1.3 User-assembled

This gives you much more freedom of choice, and perhaps a bewildering range of options. However, there is the potential to get a much better system for the money available. Moreover, such a system can easily be changed and upgraded to meet future requirements.

As self-assembly is potentially the most economical way to obtain a virtual organ, probably the majority of systems are in this category. Components may be obtained in one or more of the following ways:

Used

For those willing to do some fixing-up, high-quality components such as a pedalboard, bench, and even a console can be bought used and re-purposed. Many pipe organs are being decommissioned in favor of cheaper and more easily maintained digital organs, and their components can often be bought quite cheaply. Alternatively, it may be possible to find a non-functional electronic organ at a low price that can be used for parts.

Many used virtual organ pedalboards are from one of these sources; it is not too difficult to retrofit them with MIDI. However, while there are also used manuals from pipe organs available at very attractive prices, MIDIfying these may not be feasible.

Self-built

Those with access to carpentry and design skills could make furniture to exact requirements, and to a better standard and/or at a lower cost than ready-made products. For those with a well-equipped workshop and good DIY skills, it may be possible to make a pedalboard from scratch. However, it would probably not be feasible to build manual keyboards.

New

Manuals are the component most likely to be bought new, as used items and self-building are unlikely to be viable options. New organ manual keyboards are often supplied as bare units that must be fitted into a mounting frame, with MIDI pistons and key cheeks added to make a complete keyboard stack. While allowing user customization, this also requires user assembly. But it is also possible to buy a customized complete keyboard stack that requires only a single USB connection to the computer.

Gifted

Yes, some people manage to get perfectly good organ parts for nothing.

6.2 Furniture Types

There are three basic categories to consider:

Console
A full console with kneeboard and wooden superstructure, usually including jambs.
Desk
A desk with kneeboard and side panels.
Table
A normal open table with four legs.

New consoles and desks will normally have to be specially made, whereas a suitable table may be readily available. In any case, it is vital that it be as sturdy and stable as possible, so that there is no movement when the manuals are played. When designing furniture, measurements need to be carefully calculated; standard clearances are in relation to the keys of the pedalboard and manuals.

The console/desk/table should be chosen/designed in consideration of the manuals, and there are critical measurement criteria dependent on the pedalboard, bench, and height of the manuals. Greater attention needs to be paid to measurements if there are to be more than three manuals.

6.2.1 Console

This has a kneeboard, side panels, and a wooden superstructure. There are usually jamb enclosures for touchscreens or physical stop controls.

Consumer turnkey systems are of this type, usually with embedded touchscreens, and often also with built-in speakers. Other consoles may be used (re-purposed organ consoles), or user-built (perhaps custom-built by an organ builder). They often use physical stop controls rather than touchscreens.

Physical stop controls will appeal to those who want the closest thing to a real pipe organ console. However, the lack of an easily-accessible touchscreen makes use of Hauptwerk and general computer functions more difficult. But with this type of console, computer devices may be considered extraneous, and so hidden away.

If touchscreens are fitted into jamb enclosures, their positions and sizes will be fixed, often in less than ideal positions. It will also be more difficult to replace them. Fitted touchscreens tend to be small, resulting in limited content and/or small controls that are more difficult to operate reliably.

In any case, jambs also limit the amount of workspace available for a mouse and/or keyboard. This may not be an issue for those with physical stop controls wanting to emulate a real pipe organ console. But it is another reason why it may not be a good idea to fit touchscreens into jamb enclosures. So in my view, it is better to reserve these for physical stop controls, and mount touchscreens on adjustable stands.

6.2.2 Desk

This has a kneeboard with a surface supported by solid side panels, but no jambs or other significant woodwork above the surface. Consumer systems without computer hardware are usually of this type; they normally contain a compartment to house the computer, and possibly fittings for components such as speakers.

Without jamb enclosures, touchscreens can be mounted on adjustable stands, leaving accessible space underneath. Thus computer functions can be made easily available.

6.2.3 Table

This is easier to obtain than a console or desk, and is used in a large proportion of component-based systems. But the lack of a kneeboard and side panels leaves cables and components open to view.

Commercial tables may not be sufficiently sturdy and stable, or be of the correct height. However, it may be possible to make a suitable table.

6.2.4 Bench

This, together with the pedalboard, is the item most likely to be recycled from an old pipe or electronic organ. It may well be possible to find a suitable used bench at a low price, as an alternative to self-building or buying new.

It must normally span the width of the pedalboard (however, some budget systems have a shallow pedalboard and a stool that stands behind it - see the photo below). For a radial pedalboard, the required span is less than for a parallel one.

Most have a wide seat with straight vertical sides. However, some have a narrower seat with curved legs ("doglegs"); this may be easier to mount (although more difficult for the home constructor to make).

The bench should be designed in conjunction with the pedalboard, to conform to the standard specifications. For example, the required height is relative to the top of the middle pedal (the AGO nominal height is 20.5" above).

Many benches have a mechanism to adjust the height (the AGO standard specifies ±2"). But although important in a public building, I would be wary about including it in a bench for home use. If not built to a high standard (as is likely in a consumer product), it will compromise robustness and stability. If only one person will ever use the bench, it can be made to a fixed height. Otherwise, the height may be adjusted by means of blocks.

6.3 Display of Music

Most systems have a music rest. However, much music is in the form of computer documents, and another option is a center monitor. This could be in addition to a music rest, if mounted on a flexible stand or bracket. The monitor could also be used for general computer operation.

This section also covers the thorny matter of page turning, with both music rest and monitor.

6.3.1 Music Rest

This sits on top of the keyboard stack. It is usually made of wood, but is sometimes of another material such as plexiglass. With four or more manuals, the rest is likely to be rather higher than ideal. In some cases, the music rest can be lowered over the top manual, thus giving a more ergonomic reading position when the top manual is not required.

The music rest is primarily for the display of music in paper form. However, many organists use forScore on the iPad for displaying music. While this has many advantages, its small screen allows only a single page to be displayed at a time. Some organists address this limitation by using two such units.

6.3.2 Center Monitor

A lot of organ music is available primarily as PDF documents. Printing it out for use on a music rest is nowadays of questionable value. Conversely, if there is a legacy of paper music, it might be worthwhile to scan it to make its use more general.

For many people, music displayed on a computer monitor is easier to read than that on paper. A monitor also offers a larger and clearer display than the iPad, and two full pages can be displayed clearly side-by-side. For this purpose, music in portrait format is more desirable than landscape, but this is the case with much PDF organ music.

For good ergonomics, both the height of the monitor and its proximity to the organist should be adjustable. It should therefore be mounted on a suitable stand or bracket. Further hints on use of a center monitor (including their use with touchscreens) may be found from my experiences with using three-screens.

6.3.3 Page Turning

Page turning is an important aspect of console usability. And while pianists are expected to perform from memory, organists usually play even standard repertory from music. With the complexities of Bach I can understand this, having practiced too much from memory (not being bothered to turn the page), only for inaccuracies to creep in.

6.3.3.1 Music Rest

There are two main options, depending on whether the music is paper, or displayed by an iPad:

Paper The usual technique is to grasp the edge of the page between finger and thumb, and pull it. There are mechanical devices that can do this, but they are unlikely to be cost-efficient or useful. A human assistant will probably be a more practical tool.
iPad The forScore application allows pages to be turned by gestures. But while the clearest type of gesture is a nod, this is a non-starter for organists, as the head is moved quite frequently while playing. Other types of gesture, such as winks, may not be reliable. And page turn refusals or (worse) uncommanded page turns will cause considerable displeasure.
If gestures are not viable, it will be necessary to touch the screen; this would in any case be required if two iPads are used to display two pages simultaneously.
6.3.3.2 Monitor

This would normally be used to display a PDF (or other format) document, and probably for other computer functions. There are several page-turning options, with a number of issues. However, there are two basic ways to change the page, using either the keyboard or the mouse:

Keyboard The keys to move to the previous or next page will usually be Pg Up or Pg Dn; in some applications the arrow keys may be used. Note however that keyboard input is directed to the focus window. While this will initially be that of the document reader, any use of Hauptwerk screen controls (for example, to change registration) changes the focus to a Hauptwerk window. Use of the keyboard will then not work until the document window is again given focus.
Mouse Pages can usually be changed using the mouse wheel. However, unlike use of the keyboard, it is the position of the mouse pointer that determines where the mouse input will go. This means that it will operate on a window that does not have the focus, but care needs to be taken to ensure that the pointer is within the document window.

While using the mouse wheel would be feasible (although less than ideal), operating a keyboard while playing would be impractical. Instead, a USB page turner (usually in the form of "foot pedals") could be used to simulate pressing of page navigation keys. But apart from not coexisting well with expression pedals, they would not solve the issue of loss of document window focus on operating Hauptwerk screen controls.

However, loss of focus does not occur when MIDI controls such as pistons are operated. So if registration changes while playing are confined to use of these controls, a standard USB page turner could be used. This can be enabled by assigning combinations to pistons as required (for example, from the master generals); with Auto-detect, this is quick and easy.

But a better solution than page turner pedals may be a USB pushbutton that can send a programmed sequence of characters. This could be either simple navigation keys, or address the focus issue by executing a PowerShell script via a Ctrl+Alt shortcut. This script would give focus to the document window before sending the required keys. Different sequences of keys may be programmed for short and long presses; hence a single button can make both forward and backward page turns. And a pushbutton can be positioned in a much more flexible manner than pedals.

One or two systems use the Bome MIDI Translator to field MIDI messages sent by (for example) pistons, and execute a PowerShell script as above. The snag is that Hauptwerk commandeers all MIDI ports it uses on startup, thus making them inaccessible to other applications. So any such controls must be on a separate MIDI port not used by Hauptwerk (requiring a separate MIDI connection to the computer). Implementing this in an existing system is likely to be (at best) inconvenient; it really needs to be a feature designed into the console. See this Hauptwerk forum thread for more info. But in my view, a USB pushbutton is a more appropriate type of control than an organ piston, and does not need MIDI.

6.4 Budget Systems

While some people spend a small fortune to emulate the console of a large real pipe organ, others spend a tiny fraction of this, yet with a similar end result and function.

The main sacrifices in a budget system are in appearance, handling, and construction. End function and the quality of the results are determined largely by the software and sample sets (and, of course, the organist!), which are the same regardless of system cost. I assume the use of Hauptwerk, but even low-budget systems often use this rather than the free GrandOrgue.

Apart from buying components used or building them, one can economize by considering carefully just what is necessary. This particularly applies to the keyboard stack, which tends to be the most expensive component, especially as used organ manuals will probably not be an option. Although generic keyboards can be used, one should consider investing in wood-core manuals even in a low-cost system, due to their longevity.

6.4.1 Generic Keyboards

I have no experience whatever of using these, so offer only general comments. More information from an organist's perspective may be found here.

These consumer-grade keyboards include products described as "MIDI controllers". Being far cheaper than organ manuals, they are normally used in low-budget systems. Apart from their considerably lower cost, they have the advantage of being widely available. They will also plug straight in as MIDI devices. Although they are not exactly organ scale (they have slightly wider keys), the difference is pretty much negligible.

Being mass-produced, they will have a limited lifespan, but this also applies to the most commonly-used organ manuals (the far more expensive Fatars). And with their much lower prices and widespread availability, they can easily be replaced when no longer serviceable.

However, it is vital to try out a number of keyboards before buying. One cannot expect wood-core action from a low-cost consumer product; in most if not all cases, the action will not please an organist. So one must find the keyboard whose shortcomings are the most acceptable. Behringer (dark red), M-Audio, and Nektar keyboards seem to be those most commonly used in virtual organs, but there are clearly many other options.

An obvious aspect of using these separate keyboards is that they will have a less elegant appearance than an organ keyboard stack. As each keyboard comes in its own case, shelves will normally be required to accommodate them, and it may not be possible to achieve the ideal vertical spacing. They will also lack provision for fitting thumb pistons, but may come with controls that could serve this purpose.

To create a look and feel more like that of real organ manuals, it may be possible to extract the bare keyboards and remount them. This page from Lars Virtual Pipe Organs may give some ideas on how to accomplish this.

6.4.2 How Many Manuals?

A typical Hauptwerk system has 2, 3, or 4 manuals. A fifth manual would probably never be utilized (I believe only two sample sets feature real organs with 5 manuals, both from Inspired Acoustics). Having only one manual would result in fundamental limitations that could not be overcome by Hauptwerk function (notwithstanding, there is plenty of music that does not require multiple manuals).

Ideally, there should be as many manuals as has the real organ, which may well mean four manuals. However, the Hauptwerk software enables one to use a sample set with more manuals than has the virtual organ, in the following ways:

Combining Divisions One manual can operate on two (or more) sample set divisions; for example, manual II could play division IV as well as division II. This is done by simply using the Hauptwerk Auto-detect function, pressing keys on the same virtual organ manual for each sample set manual it is to play.
Using Floating Divisions This solution is used where the above is not applicable, as the divisions must be played separately. One or more divisions can be made floating, and coupled to a manual as required. Such coupling can be done while playing, by means of pistons. This youTube video Floating Divisions in Hauptwerk shows how. This function would perhaps be better termed "Floating Keyboards".

As a result, having fewer manuals than the sample set is unlikely to be a fundamental limitation. The compromise would be in different handling and some loss of convenience, compared to having a full set of manuals.

But apart from being more economical, having fewer manuals may otherwise be better ergonomically. The more manuals there are, the higher and deeper is the keyboard stack. Not only are the higher manuals more difficult to reach, but the music rest is likely to be higher up than is ideal. Moreover, positioning of the touchscreen may be compromised; for ergonomic operation, it should be as close as possible to the manuals, and fairly low down. So, for example, unless a fourth manual would offer really significant benefits, it may be better to stick with three.

6.4.3 How Many Expression Pedals?

As in consideration of the number of manuals, this is based principally on the sample sets one is likely to use. Relatively few organs feature more than one swell division, and these are mainly large romantic or symphonic instruments. Moreover, swell pedals can be floated in a similar manner to keyboards (divisions). So having only one swell pedal is unlikely to be a fundamental limitation.

But another use for expression pedals is for crescendo. Even if the real organ has no crescendo pedal, it may be desired to use the master crescendo function of Hauptwerk. Thus, it may be a good idea to provide at least two expression pedals.

Of course, much music, including that written during the baroque period, does not require any expression pedals. And it should not be too difficult to add these later.

6.4.4 How Many Pistons?

This section mainly applies to both thumb pistons and toe pistons.

Traditional use of pistons involves large numbers of divisional and general combinations, as well as other functions; according to conventional wisdom, there should be about 20 on each manual. But pistons available for virtual organs are very expensive for what they are (pushbuttons); the most basic cost from US$15 to US$25 each (and by many accounts, commonly-available US$15 square pistons are unsatisfactory). On this basis, the pistons alone would account for a large proportion of the total cost of the manuals.

The good news is that very few pistons are really needed. The registration functions of Hauptwerk provide considerably more function than the pistons on a real pipe organ. Thus all the required function (and much more) is available on the touchscreen. Pistons are only needed for function that must be operated while actually playing; this essentially means that required for quick changes of registration.

And instead of using numerous divisional and general pistons for this purpose, one can use the combination stepper. This requires only two pistons; one for the next combination, and one for the previous one. For maximum speed of access, these can be duplicated on each manual without undue expense. With the Hauptwerk software, using the combination stepper is probably simpler as well as much more economical in pistons. Cueing and triggering, as well as setting, can be done on the touchscreen.

However, it may be a good idea to provide a few extra pistons for ad-hoc purposes. For example, they could be used to trigger frequently-used or current combinations to avoid having to use (or even power up) the touchscreen. And using these instead of a touchscreen for registration changes while playing avoids problems with page turning using a monitor. Pistons may also be needed to couple floating divisions on the fly.

Instead of buying special organ pistons (which apart from being inordinately expensive, may not be of very good quality), it may be possible to utilize general-purpose pushbuttons. This section on thumb pistons may give some idea of what options are available.

Yet another way to save on pistons is to use keys for this purpose. As the top 5 keys on a 61-key manual are unlikely to be played, they could instead be used as thumb pistons. This is done by simply using the Hauptwerk Auto-detect function, pressing the required key as the MIDI device to set. Similarly, with a 32-note pedalboard, the top 2 pedals could be used as toe pistons (perhaps for the combination stepper).

And as noted above, generic keyboards may have buttons that generate MIDI messages; again, Auto-detect would be used to assign them function as pistons.

6.4.5 A Basic Baroque Virtual Organ

If the user has only limited requirements, it is often possible to meet them fully with a simple and economical design. For example, a perfectly functional organ for baroque music can be built with only the following MIDI devices:

Even in baroque music, two manuals are required for quick changes of registration, and playing with each hand on a separate division. But sample sets with more than two manuals can be handled as described above.

While thumb and toe pistons may be convenient, they can hardly be considered necessary for baroque music. Prodding a touchscreen is much quicker and easier than yanking and shoving the drawbars on a real baroque organ (although perhaps less satisfying😜).

Also bear in mind that if only sample sets of fairly small organs are to be used, processor and RAM requirements will be relatively modest.

7 What I Got

After having first looked into virtual organs several years ago, I finally took the plunge (at the age of 66!) with the first purchase on 8 November 2021. After many difficulties, I finally got the system working on 15 July 2022.

There are many ways to go when assembling such a system, and I am pleased to have found what for me is the right way. Although putting it together was no picnic, the satisfying outcome has made it well worth the trouble and expense.

7.1 Considerations

I have never even been near a pipe organ console, nor is anyone ever likely to allow me near one. So emulating its look and feel is less important to me than easy access to all Hauptwerk and auxiliary computer functions. Moreover, the system is for my use only, and then primarily for Bach (although with a view to handling other music in the future). So my criteria are very different from those of an experienced real pipe organist who wants a system that feels familiar, and is suitable for use by other people.

I did not have a specific budget, but did not want to spend any more than necessary to get a good-quality system. This was especially as I was a complete newcomer to the organ, and had not played any keyboard instrument for 50 years. If I did not take to it, the system would be a serious waste of money. At the same time, I was keen to avoid the following:

I was never attracted to pretty ready-built packages; these would deny me free choice of the components, and result in a poor quality/cost ratio. I saw little prospect of getting good used organ components here in Mexico (those I have seen advertised do not ship here). And I am no DIYer. However, I have experience with AutoCAD (being the architect of my own house), and can get furniture custom made by local carpenters at moderate cost.

So my system is based on new separate components, with carpenter-built furniture. I divided purchasing into the following four phases:

Pedalboard & Bench 30 or 32 notes, to AGO or BDO standard, with bench made to my own design.
Manuals & Desk A stack of from two to four keyboards, with customized pistons, and desk made to my own design.
Electronics Computer box, center monitor, touchscreens, audio interface, headphones, etc.
Software Virtual organ system software (Hauptwerk), and sample sets.

7.2 System Overview

The pedalboard and manuals were supplied in bare wood by PedaMidiKit, and finished by local carpenters. PedaMidiKit (Alessandro Alfieri) puts construction and playing quality at a low price before cosmetics and unnecessary features. Nonetheless, after finishing I think they look quite handsome, and fit well with the rustic room decor. I expect they will last longer than I will, and I am delighted with the way they play.

The desk and bench were built by the carpenters to my plans. This was not only considerably more economical and problem-free than importing ready-made products of comparable quality, it also gave me exactly what I wanted.

The system is perhaps unusual in being dominated by three large screens; two touchscreens to the sides for Hauptwerk use, and a center monitor instead of a music rest for displaying music and general computer functions. These are driven by a mini PC with low power consumption but impressive performance.

The console layout incorporates audio output devices and computer input devices. The computer system is fixed to the wall behind the desk, out of view, but with an accessible power button (rarely used) and USB ports.

7.2.1 What It Has

Main Components
Pedalboard PedaMidiKit AGO 32
Bench After a copy of a model by Laukhuff
Manuals PedaMidiKit K3 61 W (Schwindler), with 16 thumb pistons
Desk Made to my own design
Computer Box Minisforum HX90 / Windows 11 Pro / 32 GB RAM / 512 GB SSD
External SSD Western Digital Blue 1 TB USB
External HDD Seagate 3 TB USB
Center Monitor AOC 27" UHD IPS, wall mounted
Touchscreens 2 x ViewSonic 22" FHD, on Vivo stands
Audio Interface MOTU M2
Headphones Beyerdynamic DT 990 PE 250
Speakers B&W 801 series 2, with Rotel amplification
Keyboard and Mouse Jelly Comb 2.4G Wireless
Software Hauptwerk 6 Advanced
Other Stuff

7.2.2 What It Hasn't

Expression Pedals For the time being, these are superfluous, as I will be concentrating on learning the works of J S Bach. They will of course be essential for later music, but can be added if and when required (by which time I will have a clearer idea of what is appropriate).
Toe Pistons I would only ever require two (for the combination stepper), and for the time being this function can be assigned to notes 31 and 32 of the pedalboard. They can easily be added if and when I add expression pedals.
Drawknobs / Tabs As I have never even been near a pipe organ console, I do not miss physical stop controls.
A Fourth Manual Adding this would be problematic, but I am confident that it will never be required, as described here.
Scores of Pistons I will be using only the combination stepper plus 10 extras, as described here.
Loads of Speakers I will use only headphones at the organ, and a separate stereo hi-fi system for comfortable listening through speakers.
A Fan Heater Neither the heat output nor power consumption are wanted here in Mexico, and I expect my cool little box will deliver all the polyphony I ever need.

7.2.3 What It Cost

Payments were made in three currencies (euro, US dollar, and Mexican peso), from November 2021 to June 2022. All values are given in US dollars, and are approximate, as they depend on the exchange rate.

The total cost (excluding the HDD, vintage speakers and amplification) was just under $10,000. This may seem high for a basic system, but includes all shipping, taxes, import duties, customs handling fees, and other charges.

A rough breakdown of gross costs (not sticker prices) is as follows:

Pedalboard & Bench $2,250 (including $1,250 for the pedalboard, $285 shipping, and $285 for the bench and finishing)
Manuals & Desk $4,000 (including $2,700 for the keyboard stack, $315 shipping, and $465 for the desk and finishing)
Electronics $3,000 (including $860 for the Mini PC box, and $850 for the touchscreens and stands)
Software $600 (Hauptwerk Advanced Perpetual)

I could easily have spent much more on a system with much less good construction quality. I especially saved on the pedalboard, manuals, and their shipping. And with the low labor costs here in Mexico, I also got a substantial custom-made bench and desk for much less than the sticker prices of comparable commercial products. But the touchscreens were more expensive than I had bargained for, and I paid about 50% on top of the shipping charges to have the pedalboard and manuals brought through customs.

For my current purposes (mainly learning the works of J S Bach), I do not believe that additional expenditure would have been productive. To me, the only significant drawbacks relate to the behavior of software, and so would apply to any Windows-based Hauptwerk system, regardless of the amount spent.

7.3 Pedalboard & Bench

This was the first component I wanted to buy, especially as I had never even seen a pedalboard, and was eager to try playing one.

I was looking for a pedalboard that was concave, and probably also radial. I also wanted 32 pedals; although I would not need them for Bach, it would make the pedalboard future-proof at little extra cost. And the top two pedals could serve as toe pistons.

A little investigation showed that a suitable pedalboard would be far too difficult for me to build, even with the help of carpenters. I also saw little prospect of finding a suitable used one to ship here to Mexico. So I was left with buying a new one.

7.3.1 Buying the Pedalboard

As Classic MidiWorks (based in Canada, with an outlet in the USA) seemed to be THE place to buy organ components, I commenced online purchase of their AGO pedalboard at US$1895. However, I was stopped in my tracks by a blanket shipping charge of US$1000 (which they said they would adjust once I had submitted my card details and made payment on this basis). As I was not prepared to do this (I am frankly surprised that anyone would be), I sent an email asking their shipping charge to Mexico. They answered many questions that I did not ask, but would not answer this one, simply restating what was said on the website. So I looked more carefully at other options.

After looking at some AGO pedalboards at around US$2500, and others that were much cheaper but plain and flat, I decided to go with a one-man business in Italy named PedaMidiKit (Alessandro Alfieri). He offered several different pedalboards, and you can also have a design customized to your requirements, as each piece is built to order.

I decided to buy an AGO 32 pedalboard (32 notes, concave, radial) at €970, plus the option of a fast reed switch replacement system. Although this is the most expensive pedalboard sold by PedaMidiKit, it is considerably cheaper than that from Classic MidiWorks. The unit was supplied unassembled and unfinished; I consider this to be an advantage, as it would be more robust to handling problems, and I could have it finished the way I wanted.

On 29 November 2021, I received an invoice for €1052, but unfortunately due to government anti-money laundering measures, I was unable to make payment until 5 January 2022. Alessandro wanted a bank transfer via Wise (formerly TransferWise), but it eventually transpired that the Mexican government does not allow such payments, as the true recipient cannot be known. On 20 January 2022, I received an email (including photos and a video showing that all the pedals worked) stating that the pedalboard was ready.

I sent the shipping agent a payment of €240, and finally received the pedalboard (in three packages) on 2 March 2022. This was a result of shipping delays and a number of communication issues involving customs handling and misleading tracking information. There was also some concern that Mexican customs would not accept the items without special treatment, as they were bare wood. On top of the shipping charge, there was a substantial fee for customs handling (otherwise, I would have had to travel a considerable distance to the port of entry to take the items through customs myself).

When the pedalboard arrived, I assembled the frame, but left the pedals separate for finishing. I gave the bench plans and the pedalboard parts to the carpenters, who delivered the finished items on 4 April 2022. After completing assembly of the pedalboard, I was last able to try playing it. However, without any sound, this proved to be of limited benefit, and possibly even counterproductive in inducing bad habits.

Using a powered USB hub, I subsequently did some tests with the pedalboard by checking its indicator LED, as a result of which I adjusted all the speech points to the midpoint of the range of travel. On 22 June 2022, I was finally able to get some sound from the pedalboard; the consequences of practicing without sound then became clear.

7.3.2 Designing the Bench

While waiting for the pedalboard, I found a home-built bench based on a Laukhuff model (catalog 9 page 24/25). This features doglegs that would be easy enough for the carpenters to make, while imparting both esthetic and ergonomic benefits.

The curves add a touch of elegance to an otherwise plain and square console. The narrower seat makes it easier to mount than a regular bench, as one's feet go over the side while rotating, giving much greater clearance under the desk.

I had not seen the Laukhuff catalog at that time, and worked only from the web page photos. No measurements were given, but they were clearly taken from the catalog. However, neither copy is (or was intended to be) an exact replica of its model.

I put some effort into developing a more esthetically-pleasing form for the doglegs. In the Laukhuff they are basically three straight sections, modified somewhat in the copy. Mine are curvier and slightly less splayed than either. They are also 5 cm thick, to give good strength and stability.

Both copies have a hinged seat with a storage compartment underneath. To enable this to hold paper music, I increased the seat depth by 2.5 cm, and the compartment height by 2 cm. In the Laukhuff, this space is occupied by a crank mechanism to adjust the height; this would be difficult and expensive to implement without seriously compromising robustness and stability.

Although essential for public use, height adjustment is not needed for my bench, as only I will ever use it. The AGO nominal seat height of 20.5" above the middle pedal is fine for me; I will not even bother with the blocks used in the copy. I also omitted the feet; having four separate points of contact is not an issue on a tiled floor, and the legs are thick and cross-braced.

My bench was designed for a 32-note radial pedalboard. However, the Laukhuff design is for a 30-note parallel one, which is wider at the bench even though it has fewer notes. The overall width is 96 (100) cm at the seat, and 128 (136.5) cm at the floor. It can be seen that my doglegs are just 4.5 cm less splayed than in the Laukhuff. The compartment is enlarged with a minimum seat depth of 33 (30.5) cm, and outside height of 12 (10) cm.

As AutoCAD did not seem to be an efficient tool to design this bench, I created only informal plans for the carpenters. These comprised a cardboard template for the doglegs, some of the website photos, and some measurements.

7.3.3 The Result

I am very pleased with the construction quality of the pedalboard. The frame is of oak, and screws together in a way that, while less elegant than dovetailing, is very sturdy. The pedals have a two-layer construction: the upper parts are of (I think) maple, with pine underneath. There are both sprung heel plates and wire toe springs. The latter provide most of the resistance, which can be changed by an alternative way of fitting them. Resistance of the heel plates can also be changed by loosening or tightening them. I received 7 spare reed switches, presumably with the fast reed switch replacement option (Alessandro seemed to be very worried about people smashing these!).

I have never played any other pedalboards, so I am perhaps not best qualified to comment on its playing qualities. However, I cannot fault the action, finding it to be firm, smooth, and responsive. Others, who presumably have more experience of playing pedalboards than I, concur that it plays beautifully. It makes very little noise when played. In all respects, the pedalboard appears to conform to the AGO specification. A more expensive pedalboard might look prettier, but I do not believe that it would be more robustly constructed, or enable me to play any better.

The electronics are based on an Arduino Leonardo controller with built-in USB. This is housed in a small wooden box that is screwed to the back of the pedalboard. Connection to the computer is USB-A via a very short wired-in cable, so you will probably need an extension. There is also a MIDI connector (5-pin DIN), but I did not check this. An LED indicates both power and reed switch activation.

The bench has a very pleasing appearance. Notwithstanding the lack of feet, it is reassuringly stable, being surprisingly heavy. It is also very solid, and will take considerably more weight than mine. Its height is just right.

7.4 Manuals & Desk

The most basic consideration was how many manuals I should get. A two-manual stack would serve for Bach, but could not easily be upgraded to more manuals to meet future requirements. A three-manual stack seemed appropriate, as sample sets with four manuals (for example, Laurenskerk by Sonus Paradisi) could be handled with little compromise. I was also looking for wood-core keyboards, with generic ones as a fallback.

I initially had little idea of how many pistons I should provide, and was concerned that this would involve considerable expenditure for little useful function. I only cottoned on to the combination stepper as a complete solution shortly before purchase.

7.4.1 Buying the Manuals

Given my experience with PedaMidiKit in offering no-frills but well-built products at a low price with honest shipping costs, on 21 April 2022 I transferred €2325 for a 3-manual keyboard stack with 16 pistons in a very substantial shipping crate (as recommended for shipping to Mexico). This unit came assembled, but in bare wood.

I was attracted by the fact that the keyboards are made by Schwindler with wood-core construction and mechanical key switches. The only other affordable organ manuals were by Fatar and used rubber domes; the issues with servicing such keyboards would be especially unacceptable for me here in Mexico.

Another advantage of PedaMidiKit is customization. My unit came ready-made with 16 pistons (well, small black buttons) with a specified layout. All I had to do was plug the USB connector to the computer. I would otherwise have had to buy a mounting frame, key cheeks, rails, thumb pistons, and electronic components separately, and assemble the unit myself (including all the MIDI connections).

Each manual has a pair of buttons for the combination stepper, and the lowest manual additionally has two groups of 5 for ad hoc purposes. I have no intention of getting involved with divisional/general pistons, nor with the different ways of using numerous pistons to cue combination stepper frames described in the Hauptwerk User Guide.

On 16 May 2022, I received notification that the manuals were completed. Again, there were attached photos and two videos showing that all keys and pistons were functional. I sent a payment of €294 for shipping. This time the process went more smoothly; there were no delays, and I was aware of what to expect.

The shipping crate was very solid and offered excellent protection from major impacts; I consider the price I paid to be very reasonable. However, I was rather surprised to see that there was no padding to cushion the unit. This might have led to some speech points going out of adjustment.

Having extracted the keyboard stack from its crate, I disassembled it so the carpenters could finish it. This involved removal of the base, and was a daunting task, as the two lower manuals were connected by ribbon cable and could not be separated. These parts (the two connected manuals taped together as best as I could), together with the plans for the desk, were given to the carpenters. On 5 July 2022, the carpenters delivered the desk and finished keyboard stack parts.

7.4.2 Designing the Desk

While waiting for the keyboard stack, I created plans for the desk (in Spanish) using AutoCAD. This required a considerable amount of care and attention, to ensure that all measurements met the standards, and that there was sufficient clearance for playing. For example, the AGO standard requires a distance of 29.5" from the top of the pedal middle D to the top of the middle D on the lowest manual. This required the pedalboard (which I already had) plus knowledge of the height of the lowest manual keys above the desk.

It was also important that it be very stable and sturdy so it does not wobble when the manuals are played. Another important criterion was that it must be simple for the carpenters to make, with no complex shapes. I went for a desk design with a kneeboard, supported by thick side panels on feet, and with a good amount of surface workspace. It is braced by elements with a 5cm square cross-section that hold the kneeboard panel, and an arched element under the manuals. Should I ever progress beyond Bach, holes can easily be cut in the panel to accommodate expression pedals and toe pistons.

I perused several products on the internet before arriving at this design. Many seemed to have features that take up valuable space, but add no value (except perhaps make it look more for advertising purposes). It is significantly different from any that I saw, but to help the carpenters understand the overall shape (few people seem to be able to work from plans), I also gave them a photo of that most similar.

7.4.3 The Result

Like the pedalboard, the keyboard stack is not super-de-luxe, but it is well built. The key cheeks are of oak, with some detailing to take off the squareness. It was well worth getting the unit finished, as this vastly improved its appearance, and made it much more appropriate for my listening room. Staining and polishing alone gave a very pleasing result; no preparation of the woodwork was required. Although Schwindler offers various types of keytop, only the standard black sharps on white naturals was offered by PedaMidiKit; however, this is what I would have chosen anyway; fancy keytops would look out of place in my system.

The keys are of acrylic plastic, and perhaps a bit slippery with my dry skin (my previous experience was in pounding the ivories). But as this issue can be addressed by a light sanding, this glossy surface is hardly a problem. And they have a solid, quality feel to them (not plasticky). Spacing between the keys is somewhat uneven, and they are not perfectly level. However, there are no serious discrepancies; these issues are purely cosmetic, and perhaps to be expected at the relatively low price.

What is most important (together with construction) is the playing quality, and on this I have absolutely no reservations. I am delighted with the responsiveness of the keys, having been worried that I would be dissatisfied with the action. From 1961 to 1973, I played both a Steinway piano at home, and some old Joannas on which it was impossible to deliver a proper performance. The action noise appears to be moderate and normal. The only shortcoming is that some of the speech points were not very well adjusted (there are instructions on how to change them, and I will get round to doing this sometime). With the exception of one problem shallow speech point combined with my short fingers, I have no reason to blame the keyboards for any shortcomings in my playing.

Like the pedalboard, the electronics are based on the Arduino Leonardo, and there is a fixed short cable with USB-A connector (again, you will probably need an extension cable).

The desk is satisfyingly stable, being very difficult to move. Although an error occurred during construction, after correction all the measurements are very accurate.

7.5 Electronics

These were mainly purchased from Amazon USA, with some from Amazon Mexico. In contrast to the expense and difficulties in buying and importing the pedalboard and manuals, buying from Amazon USA was a breeze. The amount of customs duty payable was estimated by Amazon, and included in the amount to pay; any excess duty paid was refunded. Lower-cost items were free of duty. Shipping was fast (a very small number of days), and inexpensive.

The basic components were purchased by 18 June 2022, and set up in another location from the pedalboard and manuals (with an internet connection as required to setup Windows 11). The computer system was then moved to the location of the organ console to connect the MIDI devices. After a period of misery, it was finally up and running on 15 July 2022. Now all I had to do was learn the organ oeuvre of J S Bach.

7.5.1 Computer Box

As I wanted three screens, I needed a computer that would drive them, which limited my options. Probably most will drive two screens, but not three or more. The Minisforum HX90 will drive four; two DisplayPort, and two HDMI. I put the center monitor on a DisplayPort, and used HDMI for the two touchscreens.

I already owned a Minisforum PC; this has half the number of cores (4) and runs at half the clock rate (1.8 GHz). Nonetheless, everything I do happens very quickly (it is very noticeably faster than my all-in-one). The additional cores are important for Hauptwerk; this with the faster clock should give around four times the performance.

It comes with mounting hardware that enabled me to fix it directly to the wall, along with the UPS and other items.

7.5.1.1 CPU

This is (dare I say it) an AMD processor - the Ryzen 9. Although it is in a small box without a fan, it has 8 cores / 16 threads, and runs at a base 3.6 GHz (clockable up to 4.7 GHz).

Yet it produces a barely discernable amount of heat and thus clearly uses little electricity. This enables me to leave the system actively running 24/7, so I can use it at odd moments (I often practice while making a coffee).

And the least of my worries with Hauptwerk is running out of processor power; the CPU load so far has been very light indeed (and I have tried drawing lots of stops, playing rapidly, and with fat chords without getting near to approaching its limits).

7.5.1.2 RAM

While 32 GB is insufficient for other than a small organ if 6 channels are to be loaded, quite a large instrument can be loaded with only two channels. For example, the 85-stop Laurenskerk Rotterdam organ by Sonus Paradisi occupies 25 GB with only the two front channels loaded (20-bit, all stops).

My current sample sets either only have 2 channels, or else give a satisfying sound from the two channels recorded in a central position. In these cases, I see no need for more than 2 channels. I personally see mixing channels as a remedy; as it does not represent a single listening position, it could be considered artificial.

Nonetheless, I do see myself upgrading to 128 GB in the mid to long term, to be able to load large instruments to handle a wider range of styles. But as I intend to concentrate on Bach for a few years, there is no hurry. And the memory should be cheaper by then.😁

7.5.1.3 Secondary Storage

The 512 GB internal SSD is dedicated to Windows and installed apps, which occupy only around 40 GB. I will rarely use hibernate, so its capacity is more than sufficient for a long lifespan.

External USB-connected storage comprises a 1 TB SSD and a 3 TB HDD. The SSD is used primarily for installed sample sets; in the unlikely event that more space became necessary, it could easily be replaced with a higher-capacity one. The HDD is used for downloaded sample sets, and general purposes where performance is not critical (for example, audio and video files, and sheet music).

7.5.2 The Three Screens

As all my organ music is in PDF format (I have no legacy of paper, as I have for the piano), I got a 27" UHD IPS monitor instead of a music rest. Apart from displaying two pages of music very clearly, it is also used for computer administration and auxiliary applications.

Cautionary Tale: The third-party code used for Hauptwerk control panels and toolbars has serious problems with multiple monitors where different scaling is used. Had I known about this, I would have bought a QHD monitor scaled to 100% (like the touchscreens), instead of a UHD monitor that requires 150% scaling.

I took some care to position the screens in the most ergonomic way possible, considering both position and angle. The touchscreens are particularly close to hand, and very convenient for both viewing and operating. And all three screens are easily adjustable by purpose-bought stands and a wall-mounting bracket. The stands give plenty of accessible workspace underneath the touchscreens for audio output devices, computer input devices, and also a mug of coffee.

7.5.2.1 Touchscreens

I decided to have two touchscreens, expecting these to be easily available at low cost. But, unlike with the center monitor, there was a disappointingly-limited selection of touchscreens at fairly high prices; many small, and low-resolution. I saw no point in having less than the maximum resolution I could find (FHD, or 1920x1080), especially as they would display content other than the jambs. I also chose about the largest size I saw (22"), as smaller touch controls would be more difficult to operate reliably.

I initially considered using the two touchscreens to display the two jambs of a pipe organ console. However, many sample sets have simplified stop layouts that occupy only a single window (even for a large organ), and which are easier to use than the photo-realistic ones. Smaller sample sets have only a single stop layout window. Thus the stops can usually be accommodated on one screen, and the other can be used for other purposes. So while my initial view was to emulate an organ console, my criteria changed to practical ones.

So the touchscreens are used as follows (left, right):

Registration Any appropriate stop/jamb screens, plus appropriate Hauptwerk registration toolbars (including all 100 master general pistons).
Other Functions Hauptwerk toolbars (Audio / MIDI / Performance, Pitch / Temperament, Recorder / Player), plus any auxiliary applications (such as a metronome and video recorder). It may also display the right-hand jamb, when using sample sets with separate jamb displays but no simplified stop layout.

I now make all registration changes while playing via MIDI pistons. The touchscreen registration controls are used only to:

With Auto-detect, assigning a MIDI piston from a master general takes only a couple of seconds. As currently-used combinations are assigned to pistons, it is not typically necessary to power up the touchscreen. For my current purposes (Bach), the 10 general-purpose pistons are fine. For music requiring more combination changes, the combination stepper will be used.

Avoiding use of the touchscreens to change registration while playing has the following benefits:

7.5.2.2 Suspending and Resuming

When I finish with the organ, I put all three screens to sleep with Ctrl+Alt+Z (a shortcut created using some Windows PowerShell black magic). I then power off any active touchscreens, using touch-sensitive controls on the front panel. This not only saves power, but also avoids insects waking up all three screens.

The computer is left running, so that if no screen is required the organ can be used immediately. Clicking and moving the mouse turns the screens back on, with initially only the center monitor powered up. If I need to update registrations, I turn on the left-hand touchscreen with the touch-sensitive control. If other functions are required, I turn on the right-hand touchscreen.

In the event of a power outage (by no means unheard of here in Mexico), the APC no-break is good for about 90 minutes running time with the center monitor on standby (a good reason to get an energy-efficient CPU!). If this time is approached, the computer is hibernated.

7.5.3 Audio Devices

For me, the MOTU M2 is an excellent audio interface. Unlike most, it has good volume level meters, which I would not want to be without (I have the unit angled inwards, so I can easily monitor them to avoid clipping).

There is a convenient power switch at the back; however, turning off the unit upsets Hauptwerk, so I use it only when hibernating the computer. But the indication of the wind noise (clearly fluctuating) at least gives me some reassurance that things are still OK!

There are MIDI input and output ports, which may come in useful if and when I get expression pedals and toe pistons (although I believe I can connect these to the pedalboard). It also offers phono output for my legacy hi-fi system. Performance and sound quality are top drawer.

I am also very happy with the Beyerdynamic DT 990 headphones, which offer both excellent sound and comfort. They are open-backed (very open), but this is appropriate for my quiet location with nobody around to annoy. The Hauptwerk system allows me to hear much more than in commercial recordings (the processing of which clearly masks a lot of important detail). Although they are high impedance, I am able to achieve more than adequate volume levels from the MOTU without a headphone amplifier.

7.5.3.1 Use of Speakers

I will use only headphones, not speakers at the organ. Apart from cluttering the console, speakers would deliver particularly bad sound in this corner location. Instead, I will route output to my stereo hi-fi system (I was never sold on the original quadraphonics, never mind 5:1, 7:1, and even more speakers).

This has elderly but venerable B&W 801 series 2 speakers on Sound Anchor stands, driven by Rotel amplifiers (pre-amp and four mono power amplifiers). The room was specially designed for high-quality acoustics, with a 4m-high bóveda ceiling and curved front wall. The speakers are positioned some distance apart to give a wide sound stage, but well away from walls. I do not believe that the coherent and spacious result could possibly be achieved with a cumbersome array of speakers clustered around the organ console.

But headphones are still better for practicing (and although the latency with 24 ms from the audio interface is not perceptible through headphones, it is through speakers, due to the time taken for sound to reach the console). The speakers are mainly for demonstrating the organ to others, and I also sometimes use them to listen to recordings I make (in an armchair, not on the bench).

7.5.4 Keyboard and Mouse

These are wireless, and sit on top of the desk to the left of the manuals (I am left-handed).

The keyboard is used to switch off the screens as indicated above. It is also used to operate the computer when required.

The mouse is used to switch on the screens, and operate the computer. The mouse wheel is also currently used to turn pages, although I am considering a USB push button for this purpose.

7.6 Software

7.6.1 Purchasing

My first purchase was actually Hauptwerk 6, which I bought on 8 November 2021, well before I had decided on a pedalboard. I was seriously worried that (following the gigantic bloatware merchants Adobe, Microsoft, et al), the next release of Hauptwerk would be available only on subscription. This already applied to the Lite edition of Hauptwerk 6, and I was afraid that this was just a stepping stone to a subscription-only product.

The total cost of use on a subscription basis would be many times the price of a one-off purchase. Hauptwerk would then be a non-option, and I would instead use GrandOrgue. But although more economical (free!), it would nonetheless be disappointing in comparison with Hauptwerk.

Hauptwerk 7 was released in January 2022 with a perpetual license at the same price. Nonetheless, I do not regret purchasing Hauptwerk 6, given what I knew at that time. There is nothing in Hauptwerk 7 that I would ever use, never mind have any need for. And there is always the option of paying for an update, should it prove necessary.

7.6.2 Issues

In this section, I point out some basic shortcomings that pervade the product, and will affect many other people. It is important that Hauptwerk users be aware of these issues, to avoid problems such as lost registrations, difficulties initializing MIDI devices, or excessive power consumption. Forewarned is forearmed! I have also checked the Hauptwerk Forum, but these issues are either not mentioned, or glossed over without clear explanation. But I have provided links to any relevant material on this forum.

Notwithstanding, Hauptwerk is a great piece of software. It has a very rich feature set, and I will probably never use many of its functions. It is also able to work with a wide variety of hardware, including old instruments that have MIDI outputs, or have been converted to MIDI. It also has to deal with many different sample sets. We should all be very grateful for the pioneering work of Martin Dyde.

7.6.2.1 Microsoft Windows

On my system, crashes occur every two to three months of continuous running, on which neither the Windows Event Viewer nor the Hauptwerk Activity Log sheds any light. And from time to time, one or both of the MIDI ports ceases to work. Most, if not all of these problems appear to be due to flaky Windows MIDI support, and require a Windows Restart (do not shut down using the Microsoft-recommended "fast startup").

So when your manuals and/or pedals suddenly stop working, don't despair over how to fix them, or even fiddle with the connections; instead, reboot (with Doc Martens) and curse Micros**t!

7.6.2.2 MIDI Ports Dialog
a) Improper Handling of Multiple Controllers with the Same Name

Two or more MIDI connections having controllers with the same name appear as a single port on one line, giving the impression that Hauptwerk has recognized only one. In fact, they coexist just fine. But they should surely appear as multiple entries in the list (with perhaps a suffix comprising an ordinal value in parentheses to distinguish the names).

In my system, the controllers for both pedalboard and manuals have the name Arduino Leonardo (and it seems that it would not be possible for PedaMidiKit to change them). This, combined with other problems that conspired to cause maximum confusion led to several days of misery; only after a complete reset of Hauptwerk that appeared to be unnecessary (see below) did it transpire that both manuals and pedalboard were indeed functional. I was particularly worried about the keyboard stack, as I dismantled this and gave it to the carpenters for finishing with dodgy wired-in connections.

b) Misleading Information

MIDI devices are only initialized by Hauptwerk when it is started; any connected while it is running will not be recognized. This applies to MIDI devices that run over USB, which the user would expect to be hot-connectable. And even if audio and MIDI devices are restarted (which they are at various points), new devices will still not be recognized.

There may be a good reason for this, but what is clearly a problem is the misleading information at the top of this window. It not only fails to make this matter clear, but even implies that this is the point at which MIDI devices should be connected. Instead, it should have stated that if MIDI devices are not already connected, it is necessary to close Hauptwerk, connect the devices, then restart Hauptwerk.

This, together with the apparent MIDI controller name conflict described above, was responsible for a lot of the misery I had in getting the system working.

7.6.2.3 Control Panels and Toolbars

These use Creative Commons code named Qt (Quick Toolbar). This will have saved a great deal of development effort, especially as it is multi-platform (so the same user interface code would serve for both Windows and macOS). There would be a strong motivation for using this code in the early stages of development, as it would otherwise have taken much longer to develop core Hauptwerk function. However, using third-party code has its problems when it comes to maintenance, design changes, and fixing bugs.

Frankly, this code does not belong in a commercial product. Its use is responsible for the some of the most serious usability issues in Hauptwerk; in addition to the following bugs is its generally non-standard and quirky behavior. Now the product is mature, I do wish Milan Digital Audio (Martin Dyde) would write code in-house to handle dialog windows with standard Windows/macOS conventions, and throw this stuff in the bin.

The types of dialog window in Hauptwerk that use the Qt code are called control panel (large and mini) and toolbar. These will henceforth be collectively referred to as Qt.

a) Improper Scaling

The Qt documentation states that it supports scaling, claiming that Qt uses the Windows display scale settings automatically; no spesific(sic) settings are required. For example, if a display is configured for 175% scale then Qt apps will see a device pixel ratio of 1.75 on that screen. In reality, Qt scaling is bananas.

My center 27" 4K monitor requires 150% scaling to render at a size comfortable for viewing. However, the touchscreens are scaled at 100%, as they have much coarser dot pitch. But Qt leaves the center monitor at 100%, while scaling the touchscreens to the inverse of that required for the center monitor (67%)!

I want to confine the Hauptwerk windows to the touchscreens, as the center monitor will be occupied with display of music. So if Qt did no scaling at all on the touchscreens, that would be fine for me. But the 67% scaling done when the Hauptwerk main window is on a touchscreen causes the content to be illegible, as there are insufficient screen pixels to render it properly.

On the other hand, if a Qt is opened when the Hauptwerk main window is on the center monitor, the lack of scaling makes the rendered information difficult to read. But on dragging the Qt from the center monitor to a touchscreen, the scale remains at 100%. This lack of scale change on dragging to another screen is a further defect (c), but here is fortuitous; dragging a Qt from the center monitor to a touchscreen is the only way to render it satisfactorily.

But not only do I have the chore of dragging each Qt I want to open from the center monitor, I am forced to have the Hauptwerk main window open on it at all times. As the center monitor is primarily to display music, I do not want to see this window. But I am forced to have a small Hauptwerk main window showing at all times (d). Worse, the main Hauptwerk window is given focus whenever a Qt is operated (e).

b) Mysterious Disappearances

The burden of having to drag each Qt from the center monitor is aggravated by the fact that it does not work reliably. On numerous occasions, the window being dragged has vanished suddenly without trace. This is not reflected in the corresponding pulldown menu item, which remains checked. One must then deselect it, and select it again in another attempt to open and drag the Qt.

c) No Change of Scale on Dragging to Another Screen

If a Qt is dragged from one screen to another of a different scale, the scaling is not changed to reflect that of the target screen (if it does not disappear in the process). But it is only this bug that enables me to get proper scaling on the touchscreens.

d) All Qts Cleared on Minimizing Hauptwerk Main Window

As described above, I am forced to have the Hauptwerk main window open on the center monitor. Moreover, I cannot hide it by minimization, as then all Qts disappear. The best I can do is to reduce the window size to the minimum possible; and this is not very small. But this behavior is no doubt deliberate, as there is no other provision for minimizing the Qts.

e) Qt Operations Give the Hauptwerk Main Window Focus

As indicated above, I am forced to have a small active Hauptwerk window on the center monitor. As this is used primarily for display of music, I want this document window to normally have the focus. However, whenever a Qt is operated, the main Hauptwerk window is given the focus, resulting in the music being partially covered.

This is a particular problem when changing registration via a piston or other control displayed on a Qt. Using the touchscreen for this purpose surfaces the main Hauptwerk window. Thankfully, this does not happen if the control is operated from a piston; therefore I set up the 10 ad-hoc pistons with the combinations that I am currently using.

7.6.2.4 Miscellaneous
a) Autosave Does Not Save

Despite the text on the Save menu bar item stating that Hauptwerk autosaves anyway, I have never known this to happen. On more than one occasion, days after changing registrations, the system has crashed, and when restarted lost the changes that I had made.

So, notwithstanding this advice, I strongly recommend saving manually whenever significant changes are made to registrations. I personally never rely on autosave for my work on other applications, as saving can be done by simply keying Ctrl/S. Unfortunately it is not so easy in Hauptwerk; saving causes the audio and MIDI devices to be reset with a general cancel, which is a deterrent to its use. Nonetheless, I am compelled to save manually. The Hauptwerk Registration menu item "Export/view current combinations as text listing" can be used to back up the entire combination set (it is saved as an XML document, and opened in the browser from which it can be saved as HTML).

It is surprising that there is such a basic issue, so if Hauptwerk does autosave, the question arises as to when this is done. Perhaps only when the user does something significant, such as closing or loading another organ? This is no good for me; I like to leave things running as they are as much as possible. I would have expected use of a timer, started when volatile changes are made, and running at a low priority to avoid pre-empting sample processing.

b) Continuous Execution with no User Input

Applications do not normally execute continuously; they carry out limited processing (typically in response to user input), and then re-enter a wait state. But Hauptwerk executes endlessly. This prevents the system from sleeping or entering any other power-saving mode, as I found when when investigating why my Hauptwerk computer would not sleep.

While this may not be a bug per se, I see no good reason for this behavior, which will clearly be responsible for guzzling a lot of electricity (especially since MDA appears to believe that only an Intel i9 Core is satisfactory). Although my processor consumes low power actively running, it would be even more economical when sleeping.

Assuming that continuous execution is necessary in order to process keys and other MIDI input, there should be a user-adjustable timeout period; if there is no user input within this period, execution would cease. It would then restart on response to MIDI input (any Hauptwerk control, piston, or whatever). Windows has the ability to go to sleep or turn off the monitors after a selectable period of inactivity - why not Hauptwerk? Setting the time-out period to Never would maintain the current behavior.

c) Inappropriate Default Setter Behavior

By default, Setter mode remains active even after the piston to be set has been pressed. Thus pressing another piston will overwrite the combination assigned to that piston. And so on for each further piston pressed, until one eventually realizes that Setter mode is still active and becomes extremely pistoff.

Thankfully this can be changed, so that Setter mode is reset when a piston is pressed. I strongly recommend doing this at the earliest opportunity.

Although I have never played a real pipe organ, my understanding is that the Setter piston must be held down while the piston to be set is pressed. This is a safe procedure, which has no correspondence with the default behavior in Hauptwerk.

d) Audio File can be created from MIDI File

This is a positive feature; the issue is with the documentation for not mentioning it.

A MIDI file can be used to create an audio file. This is done by playing the MIDI file, then pressing Record at the appropriate moment with Audio armed. Thus the initial whitespace (for example setting the registration) can be skipped over. One can also pause the playback to make changes to such things are registration, pitch, and tempo. The recording can be stopped in the usual way. Thus it is not normally be necessary to arm Audio with MIDI.

I am generally very happy with the Hauptwerk recording facilities, which should be used as soon as one is able to play a piece to a reasonable standard. I find particularly useful the Record button with a line through it; this stops the recording and tosses it. I also find it useful to experiment with different tempi and registrations on playback, to find which I prefer (it is necessary only to pause after the registration is set, change it as required, then continue the playback).