Ron wrote in message
...
On 04/10/2011 08:09, N_Cook wrote:
wrote in message

...
On Oct 3, 12:01 pm, wrote:
you can play through a vib ip with no pedal sw and its fine, so not a
V2.....onwards problem

What are the tubes designations for V1? It sounds like some sort of
cap problem? Have you tried shotgunning it and changing all the caps?

++++

I will get inside it today. Seems odd that varying the associated tone
controls has no effect on the whistle tone or level




That should give you a clue...



Ron


Not to me . The HV side corner of the board , not the nearby cap wires, is
extremely microphonic. Only mV DC lowside of the .1 and .047 uF caps .
Removing the fixing screw through the whale-hide or whatever junk that
passed for circuit board then, does seem to stop the noises. Some thin FRPB
will go between the 2 bits of whale-hide and an insulated collar under a
longer screw will go back through there. Consistent 2 to 3 volts on DVM
probe around the edge of the whale hide normal ?