Electronics on my Allen MOS-1 120C Organ

[fasote]

Good Afternoon

Have gotten my 40 year old Allen 120-c working and have really been enjoying it. If you remember, I was on the fence between the Allen 120c(free and already in my house that was completely silent) and a Rodgers 145 ( analog and 600.00) I am a "rank" amateur to say the least. Did burn out the two 100 watt amps (crossed a live speaker wire) on the organ and it was not worth the 300.00 each to repair. Did buy a older Techniques amp and a graphic equalizer at the Goodwill; this works but the principle channel is so much weaker than the flute. Is this normal or did I do something to the electronics or is it time to buy the Midi card and convert the sucker?? Though as a beginner, I am not completely using the organ to its capacity but am getting there fast. I presently have a single channel preamp (with this thing on full I can't tell a single bit of difference with any receiver) and several powerful amps/receivers. Remember, this is in a house- do not want to crack too much plaster..do not need to fill a concert hall - till I learn how to play it...;) Some days the principle channel is fine and then starts clipping out, then it completely disappears for a while and comes back on again - highly annoying. Bach does not sound good on just flutes.

[cantornikolaos]

I've had hat happen on an old stereo. Try cleaning contacts for both channels and any potentiometers that may be in the circuitry. That's where I'd start. When electronics get that old, stuff is bound to get dirty or oxidize.

[Guest]

Have gotten my 40 year old Allen 120-c working and have really been enjoying it. ... Did burn out the two 100 watt amps (crossed a live speaker wire) on the organ and it was not worth the 300.00 each to repair. Did buy a older Techniques amp and a graphic equalizer at the Goodwill; this works but the principle channel is so much weaker than the flute. Is this normal or did I do something to the electronics ...??

Those burned-out amps would be the Allen S-100, right? Didn't they have an input from the Expression pedal to modulate the volume of the principle channel? (This is what complicates replacement of those amps.) What did you do about that? - are you trying to compensate statically with the graphic equalizer? Without dealing with that Expression input, you could have exactly the symptom you report: a very weak principle channel.

[OrgansR4Me]

JBird was kind to help me with questions about my S100 problems. He also mentioned other brand installations require compensating for the expression input. I'll look it up and post his comments.

"If you want to do it up right, you'll want to insert an expression capacitor into the cable leading from the expression pedal, since that capacitor would have been mounted inside (or on top of) the S100 and will now be missing."

[John Vanderlee]

A related question: I am resurrecting an Allen 123C to give to student for practice. I got it at an auction and is actually in decent shape, but it came with the wrong bench(too low) and no music rack. Does anyone have a 100 series "carcass' around that these could be salvaged from? The bench would be the one with slanted legs. Any and all advice appreciated. If possible, reply to my email? [email protected].
Thanks!
John