[HAM] B3 Swell Capacitor

[Christoph Kukulies]

Jordan Kersten schrieb:
> Hi Guys.  I have a B3 that has a little problem.  When the expression pedal is all the way down, I get a sort of feedback noise.  It sounds like tube microphonics, but it is for sure the swell capacitor box.  The organ becomes very sensitive to cabinet vibrations and will make a low "feedback" type of sound.  It only happens then the pedal is all the way up and the drive level is anywhere above all the way down.  The expression pedal link is adjusted correctly and the trouble is definatly with the swell box.  Any ideas?
>   

If you are absolutely sure that it isn't a microphonic tube (6C4 tends 
to be) and you have swapped tubes
before then I would take out the AO-28 and examine the swell capacitor 
house and the innards
for cold solder joints and loose screws on the solder lugs.
Ah, yes, check the trim capacitor screw if it got loose, first.

Christoph