Hi
Repairing "unobtainium" potentiometers is not a very interesting subject but for AVSA's diy'ers who may run into a similar problem with a ganged balance pot from a vintage valve amp, there may be a way out...
There was an issue with a broken balance pot on my SCA-35 and I soon discovered the item was 'unusual' and a new part now unavailable, so I had to make a plan.
This is how I fixed the problem:
1) Postpone the job for a while
2) When it irritates unbearably, take a deep breath and just do it
After I de-soldered the spaghetti bolognese, the control was removed and carefully opened. The problem is in plain view - a broken in half wiper which was originally riveted to the spindle.
I used a locally developed industrial grade epoxy and re-bonded the pieces. As it was too risky to re-rivet the shaft to the wiper, I machined a .5mm groove in the shaft and locked the wiper firmly to the shaft by fitting a very small retaining ring into the groove.
After re-assembly, the repaired item was re-installed and all is well. I'm happy to report there are no burned wires and they are back in exactly the same orientations as before.
mafioso
Repairing "unobtainium" potentiometers is not a very interesting subject but for AVSA's diy'ers who may run into a similar problem with a ganged balance pot from a vintage valve amp, there may be a way out...
There was an issue with a broken balance pot on my SCA-35 and I soon discovered the item was 'unusual' and a new part now unavailable, so I had to make a plan.
This is how I fixed the problem:
1) Postpone the job for a while
2) When it irritates unbearably, take a deep breath and just do it
After I de-soldered the spaghetti bolognese, the control was removed and carefully opened. The problem is in plain view - a broken in half wiper which was originally riveted to the spindle.
I used a locally developed industrial grade epoxy and re-bonded the pieces. As it was too risky to re-rivet the shaft to the wiper, I machined a .5mm groove in the shaft and locked the wiper firmly to the shaft by fitting a very small retaining ring into the groove.
After re-assembly, the repaired item was re-installed and all is well. I'm happy to report there are no burned wires and they are back in exactly the same orientations as before.
mafioso
