Allen T12-A Help needed

[Birdy9897]

Hello! I recently got my first organ, being a 1965 Allen T12-A. Its condition is fairly good for its age, but it does have some technical problems that I would like to fix. Some of its problems I have listed below, if anyone would be willing to give their advice:

• Although all stops are working, some keys do not work on some stops. These such keys instead make a sort of clicking sound when pressed.
• The pedalboard is very quiet.
• There is a ringing sound coming from the bell stop. The sound stops when the Bell, Celeste, or 'C' stops are pulled.
• Keys above C#4 (I think) are not working on the pedalboard.

Any help that anybody could offer would be greatly appreciated, thank you for reading.

[Larason2]

First step would be to clean all the bus bars, bus bar contacts and switches with a contact cleaner like deoxit. I'm sure you'll be amazed at just how much this smartens things up. Then it's important to be sure that there aren't any keys that are dead for every stop, since that implies an oscillator or divider that is out. If the oscillators/ dividers are all ok, then for the notes that are giving you trouble, there is probably a component in the signal chain that is not working, which will have to be desoldered out and replaced. It's time consuming work, but I'm sure you'll be pleased with the result! These organs sound gorgeous when everything is sorted out.

[Organkeys Jones]

Larason2 - good advice about the bus bar contacts. This organ, however, does not have dividers.

[Larason2]

Ah, ok. Thanks! I was just thinking it was similar to other analog organs I knew something about!

[MarkS]

This organ has one set of flute (sine wave) oscillators. Non-flute voices are just various pitch combinations of the flutes, e.g. Clarinet 8' consists of Flutes at 8', 2 2/3', and 1 3/5'. It does not have frequency dividers. Is a given dead note on the Flute 8' the same dead note on the Flute 4' an octave lower? In such cases it would likely be a dead oscillator. My experience with one of these was with keying capacitors causing dead notes with just a click. The problem developed if the organ was not played frequently.

[Organkeys Jones]

I don't know what year Allen started producing the inline tone generators. Those are easy to service, once you determine it is a dead note instead of bad contact. Clean the contacts as Larason2 recommended including the pedal contacts. Check the wiring on the pedals for those dead notes. You have just one set of flute generators. A 16' or 8' flute on the bottom octave of the keyboard will identical to the same pitches on the bottom octave of the pedals.

I have an Allen analog service manual and probably can give some additional help. But clean all contacts first. In fact, make sure those upright thin wires are making contact. I have seen some that were bent.