bleedthrough problem with vintage deluxe electric mistress....

[bobster]

hi guys-

i just got an old deluxe EM with integral mains lead , silver with black writing colour scheme / 4 internal trim pots , prob late 70s early 80s.
its real nice but i noticed at gig last night there was a bleedthrough notchy swirly sound when i wasnt playing - not too loud but noticeable just the same

the switch is original and makes quite a bang thru speakers when putting effect on and off . i had the device near the end of my chain going into a boss delay and then into a home made rangemaster to a vox ac30. [ the rangemaster is quite wild and i wonder if it was amplifying the swoosh somehow? ]

is there a way i can dial this out or use shielded wire or something to stop it happening ?
could it be symptoms of an old switch ?
could i dial this out with internal trimmers ?

any advice much appreciated
thanks - rob

[bluesdevil]

My guess is that you may need to rewire the footswitch so that the input of the effect is grounded when in bypass. Look for the wiring diagrams on General Guitar Gadgets site for info. Oh yeah, if the switch isn't a DPDT wired for true bypass, but a SPDT that would probably contribute to the problem.
      To stop the popping you can try tacking on a 1M resistor from input to ground on the circuit board side of the foot switch(not on input lugs). If  have volume control you should also tack a 1M resistor on the output of the circuit before footswitch connection.
        Hope that gets you on track and perhaps somebody else can chime in case I might've missed something that could help.
       

[bobster]

thanks man ,
the switch is not dpdt so i'll look into that
b

[bluesdevil]

Hi Bobster - Changing the footswitch to DPDT should do the trick and you might want to still check into wiring it for grounding the input when bypassed.
Correction on the 1M resistor on the output statement:
I meant to say if you "didn't" have a volume control on the output you would need it there also.
      Good luck!!