Organ
Console

Free Organs and Tools

Organ Sample Set Enhancement SheetMusic,  Audio,
and MIDI Files

Möller Organ
Digital Extension

Audio

Organ Building Page

Organ Building Page

A Project To Convert a Schober Analog Organ to MIDI


Part 1 : A two manual organ with drawknobs


This page descibes modification of my old Schober organ console to output MIDI signals. The purpose is to use it with the Hauptwerk organ simulator program. The Schober Recital Organ was built as a kit in the early 1970's and used analog frequency divider tone generators. Much better sound is available today using modern digital computer technques.
A modern digital organ needs keyboards, pedalboard, and stop controls which are simple on-off switches which are encoded to MIDI signals by an appropriate encoder board. This is different from the original analog scheme which actually switched tone signals at various pitches.

Essentially, the only thing saved from the original Schober design was the cabinetry, which is very sturdy and has a nice furniture walnut finish. The pedal board was converted first so that it could be used with external MIDI keyboards. All the electronics from the console was ripped out and discarded. Unfortunately, I also had to discard the original keyboards because they could not easily be used to output On-Off switch functions. The same was true of the stop tablet assembly. Drawknobs were substituted for the stop controls because they are more conventional of true pipe organs, and could be made easily.

The keyboards were purchased from Classic Organ Works in Canada www.organworks.com. These are 61-key units with built-in preset buttons. The two keyboards are fully programmable and work perfectly.

Click on pictures for larger images. Click again to reduce.

Organ console with cutout for keys

Console cutout for keyboard installation.

Organ console with lowered keyshelf

Console with lowered keyshelf. The new keyboards require 0.75" more height than the old Schober units.

Stops and Controls

Keys, Stops and Controls of the Completed Organ

The new keyboards were purchased from Classic Organ Works in Canada.

Final Installation of MIDI Organ Conversion





Part 2 : Add a Third Manual and Touchscreen Control



After languishing with only two manuals for several years, I have finally added a third one to my Hauptwerk setup at very low cost. I started with the least expensive Yamaha 61-note keyboard, then dismembered it and removed the unwanted casework, controls and speakers.


For years I was discouraged from adding three manuals since the Schober console was built for only two. Moreover, it soon became apparent that the original design with mechanical drawknobs was awkward for use with the various organ sample sets that I use. With the original 34 drawknobs it was impossible to properly label them for use with different organs. Also, many organs have more than 34 stops.


The answer is touchscreen control with all stops and couplers custom displayed for each virtual instrument. This made the mechanical drawknob panel superfluous. The drawknob panel could then be removed to make room for the third manual.


Click on pictures for larger images. Click again to reduce.

Yamaha YPT-210

The Yamaha PYT-210.

Yamaha YPT-210 underside

Underside of the Yamaha PYT-210 with bottom panel removed.

Pads on Circuit Board are contacted by conductive rubber switch buttons

The circuit boards have pad patterns which are contacted by the conductive rubber on the switch buttons

The key assembly removed from the YPT-210 case.

Stopknob Detail

Underside of key assembly.

The key assembly can be modified for auto-on by placing a jumper or resistor between the contact points for the ON button.

The protruding panel under the keys (the "key slip") is removed such that the assembly can overhang the manual below it.

mounted

The new keyboard mounted above the other two.

Closeup of the three manuals with wood trim added.

The finished project.

mounted

Touchscreen controls for a favorite three manual virtual organ - a highly customized Surround Sound Cavaillé-Coll.

mounted

Touchscreen controls for another highly customized virtual Surround Sound organ.


Part 3 : The MIDI Pedal Board Project

A pedal board from an old analog electronic organ (Schober Recital Organ) was converted to output MIDI signals. Similar units from old pipe organs are sometimes available surplus.
The original pedal board had no switches of any kind, and was designed to press down on levers attached to analog switches in the console. I decided to use magnetic reed switches because they are reliable, low cost, and have versatile mounting and adjustment properties.

The switches are mounted on copper "nails" which are tapped into predrilled holes in the wood frame. The "nails" are actually just short pieces of #14 bus wire as used in electrical house wiring. Magnets are mounted on steel hex-head screws which are partially screwed into the wooden pedal boards. No glue is used, the magnets just stick by themselves.

The advantages of this arrangement are that the switches are soldered to the copper "nails", and adjustment is made by simply bending the nails back and forth, and/or turning the magnet screws in and out.

The keyboard encoder was purchased from Classic Organ Works in Canada www.organworks.com. This a 61-key unit, and the excess above the 32 pedal notes was eventually used to sense other organ control positions. This encoder seemed to be the best buy because it includes a built-in MIDI-merge function. The encoder works perfectly.

Click on pictures for larger images. Click again to reduce.

Original pedal board

Original Schober pedal board

Switches and magnets installed

Reed switches and magnets installed.

Switch installation and detail

Switch Installation Detail and Wiring. Diodes for the scanmatrix are connected between a bus wire and the switches. The reed switches and magnets were purchased from DigiKey.com.

The Keyboard Encoder. The encoder
uses a scanmatrix with 8 columns by eight rows.

Encoder intstallation

The Keyboard Encoder Installed Directly on the Pedalboard.

The completed MIDI pedalboard.

MIDI Instrument

My first MIDI instrument. This used a Roland Electric Piano and one Classic Organ Works keyboard on a simple stand. This predates the conversion of the Schober console (visible on left) that was described above.