The Finished Organ

I had originally intended to keep the blog in line with the build of the organ, however the organ was completed faster than the blog! 

As a result the finished organ can be seen here. The 'Build Blog' will, however, continue to be updated to document the various aspects of this project.


The organ was built around a pedalboard sourced from eBay in October 2013. Following a two month planning and research phase, the build started in early  December 2013. The organ was finished in mid March 2014, after a three month build (mainly weekends, Christmas holidays and the odd evening).

The organ is a practice instrument for my daughter. It has to live in a small spare bedroom, so I didn't want to build a full width console, it would have been too big. I decided to build a console that would sit on top of the pedalboard, not span it. The manuals are cantilevered off this. It makes for a compact design, and following the build I'm pleased to report that it is rock solid.

A Hauptwerk based Virtual Pipe Organ

The organ uses the Hauptwerk virtual pipe organ software system. This receives MIDI commands from keyboards and control boards, and plays the appropriate notes, using a sound library of actual recorded organ pipes.

The organ is currently configured to use the 30-stop English romantic organ recorded from St. Anne's, Moseley in Birmingham. This organ sample (supplied with the free edition of the software) showcases many of the Hauptwerk capabilities, including expression, tremulants, crescendo, bass and melody couplers as well as a fully working combination system identical to the original organ.

Brief Organ Specification / Description

The organ has be designed to conform to BOC / AGO standards (although these don't agree on many dimensions!). As a practice organ it is important that it helps develop the 'muscle memory' needed to play this complex instrument. This is discussed in more detail in this blog entry.


The two manuals are modified M-Audio 61es keyboards, built to a BOC configuration ( specification / design is based upon a design published by Organworks ). The console design accommodates the current two manual set-up, but there is space in the console for a third manual if required (in the meanwhile the space makes a nice music shelf).


The thirty key pedalboard has been modified with the addition of magnetically actuated reed switches. These form the switching circuit for a programmable board ( a Teensy 2++ ) that generates the MIDI signals (via a USB connector) that the Hauptwerk system requires.

Swell Pedal

A single swell pedal has been included. This uses an M-Audio EX-P Expression Controller that is wired into the volume control on one of the keyboards. This routes the MIDI signals from the swell pedal through the existing keyboard interface.


Momentary push switches (see right) have been used for pistons. These can be configured for different organ sets, but five pistons have been allocated to each manual, the pedal board and for the whole organ. The remaining pistons can be allocated to couplers etc.

Ten foot pistons are planned, but haven't yet been included in the organ. 


An old iPad 1 has been pressed into service for organ registration. The iPad is connected wirelessly to the Mac Mini that runs the Hauptwerk software. An app enables the iPad to act as a third screen, that can be use to display the virtual console for the organ. The touch screen allows the stops to be selected / de-selected. 


A computer is at the heart of any virtual pipe organ, and this instrument is controlled by a Mac Mini that drives the Hauptwerk software. The Mac is remote from the instrument, and is connected via a 10m active USB extension cable to a four port USB hub at the organ that interfaces with the two keyboards and the two Teensy 2++ boards.


Although the full Hauptwerk system is capable of supporting 512 audio channels, this practice organ is in a small room, and a simple 2 channel setup is used. This consists of a USB audio interface (Avid Fast Track Solo) powering a pair of 70W M-Audio BX5 D2 reference monitors. This is more than adequate for current use, although it would be nice to add a sub-woofer (eg. M-Audio SBX10 ) for the delivery of a richer bass sound.


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