||In the Beginning
This site describes my adventures with a Schober Recital organ, a transistorized electronic organ built from a kit. It contains literally thousands of electronic components which took months to solder together back in 1973. Even more challenging for me was assembling the console, the bench, and the full 32-note AGO pedal clavier. The result is a two manual electronic organ suitable for performing classical organ music.
But after 34 years, the organ and especially the keyboards needed a thorough cleaning and restoration, now mostly completed. On these pages I've described the entire process of cleaning contacts in detail, as well as adjusting the pedalboard.
Beyond restoring the original Schober circuits, I'm in the process of adding MIDI outputs which will play three ranks of pipes. I think Richard Dorf would have liked the interface I've designed, since it won't interfere with the original analog circuitry.
I hope this site will encourage other Schober owners, whether they have the Recital, the Theater Organ, the Consolette II, or some other model, to dust off their instruments and get them back in good working order. Since Schober organs are often available for minimal cost or even for free, anyone can become a Schober owner by investing the time to do the restoration.
Either way, be sure to check the Schober Organ Orphans web site for lots of useful information, and to sign up for their newsletter if you haven't already.
(Note that all pictures on this site can be clicked for larger versions. To return to the text, use the Back button on your browser.)
Finally it seemed that something would have to be done. I
searched in vain for Schober Organ Company, only to discover they were
out of business. Eventually I found out about Devtronix, and
ordered a set of their tone generators. Although the Devtronix
generators solved almost all of the keying problems, they also changed
the sound of the organ. For the most part, I didn't like the
Devtronix sound as much as the original. (See my Devtronix page for details and possible solutions.)
In the photograph at left, the blue object inside the organ is the power supply for the Devtronix generators and reverberation unit.
|I ended up installing a Devtronix generator only on the Swell, and continuing to use the Schober generators for the Great and the Pedal. As shown at left, this was a rather temporary installation since I wasn't entirely happy with the results. (The green board at left is the generator, and the one at right is a Devtronix reverberation unit. ) But as the years went on, the keying became unreliable even with the Devtronix generator.|
|From time to time members the Schober Organ Orphan group reported good results using DeoxIT contact cleaner, but I wasn't anxious to unsolder the keyboard cables so I put off trying it. Finally I decided to add connectors, as shown at left, to the keyboards before cleaning the contacts. Although it was a lot of work, it was a good investment because the first time I re-installed the Swell keyboard about 25% of the notes were still bad -- and that was with the Devtronix generator. With the connectors, it was easy to remove the keyboard again to do more cleaning.|
|The cleaning itself was time consuming but not especially difficult. The contacts on the Great keyboard were in the best shape, possibly because they are in a more protected location than the Swell or Pedal key contacts.|
|Although most electronic components in the
had fared well after 34 years, there were a few obvious problems.
The lovely red and black test prod wire furnished by Schober to
distribute power had become sticky and covered with dust, exuding some
sort of corrosive substance onto the terminals of the power
supply. I carefully removed all of this, cleaned the terminals
with isopropyl alcohol, and installed number 16 red and black
automotive primary wire in its place. Note that the color
coding on at least some Recital organs is a bit unconventional: red is used for the negative supply
voltage, and black for the positive supply, which is treated as circuit
ground. This results from the use of PNP transistors in early
Recital organs. If possible verify the polarity with a meter before replacing any of the power distribution wiring.
I should mention that the thermal circuit breaker in my Schober power supply never was reliable, so I long ago replaced it with a 3-amp fuse in an inline holder.
|Almost all the large electrolytic capacitors
show signs of fluid leakage, and they will eventually need to be
replaced. A check with a capacitance meter showed that they still
have normal capacitance despite the blistering and chemical leakage visible in
the picture at left. Since replacement capacitors are physically smaller
and just don't have the same antique charm, I decided to wait until the
old ones actually start causing problems.