Super Reverb vibrato thumping, channel interaction

[Brett Pearson]

I am repairing an early silverface super reverb for a friend and have a problem with the vibrato. It thumps until the intensity pot is turned all the way up and then it is fine. Incidentally, the vibrato channel is also much louder than the normal channel and when using the normal channel and activating the reverb or vibrato pedal, you can hear a bit of the effect coming through. I am wondering if there is some conduction on the eyelet board or a wiring issue that is bleeding the two circuits together and causing more gain in the reverb channel and interaction on the normal channel as this had been modified previously and I have been putting it back to stock (with a bf bias control). I realize its hard to diagnose this without knowing exactly what was previously done but any help pointing me in the right direction will be appreciated.

Brett

[acorkos]

i have had good results reducing the vibrato thump by moving the wires around (lead dress) on the V5 socket....set the intensity pot to where the thump is the loudest and grab your wood/plastic probe and start leaning on the wiring