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I recently got a used 1988 Princeton Chorus solid-state black-knob amp. The amp has two inputs and the first input jack was all... jacked up. So I ordered a new Fender stereo jack like this one:
Fender Stereo Amp Jack
I used my solder sucker tool and removed the old jack, inserted the new 9-pin jack into the 9 holdes and soldered it into place, being careful not to make cold-solder joints. I also resoldered the four big grey block-like components (I think they are resistors?) because I had read they sometime come loose on the amps and cause problems. I put everything back in and everything on the amp works as it should (clean, reverb, overdrive, limiter, chorus) but the amp has a hum that is just annoying enough to make the amp unusable. I have a mexican strat with vintage style pickups (not the Noiseless variety), but I have previously changed the electronics to a Toneshaper circuit as well as fully foiled the body cavities.
I have isolated the problem to the Princeton Chorus amp, because I plug the same guitar directly into my Deluxe Reverb Reissue amp using the same guitar cord and there is no hum, and no change whether I touch the strings/bridge or not. But then I plug the same guitar and cord directly into my Princeton Chorus and it gives me a hum that goes away when I firmly tough the stings/bridge.
Both amps are plugged into the same power strip. I know this amp is very old, so do I need to replace any of the capacitors, and if so which ones? It sounds like a grounding hum, so is there something else I need to do with the new input to connect grounds or something? I used the metal washer and nut that came with the Fender input, just like all the other jacks on the same amp use.
Thanks for any ideas and experience you have.
Fender Stereo Amp Jack
I used my solder sucker tool and removed the old jack, inserted the new 9-pin jack into the 9 holdes and soldered it into place, being careful not to make cold-solder joints. I also resoldered the four big grey block-like components (I think they are resistors?) because I had read they sometime come loose on the amps and cause problems. I put everything back in and everything on the amp works as it should (clean, reverb, overdrive, limiter, chorus) but the amp has a hum that is just annoying enough to make the amp unusable. I have a mexican strat with vintage style pickups (not the Noiseless variety), but I have previously changed the electronics to a Toneshaper circuit as well as fully foiled the body cavities.
I have isolated the problem to the Princeton Chorus amp, because I plug the same guitar directly into my Deluxe Reverb Reissue amp using the same guitar cord and there is no hum, and no change whether I touch the strings/bridge or not. But then I plug the same guitar and cord directly into my Princeton Chorus and it gives me a hum that goes away when I firmly tough the stings/bridge.
Both amps are plugged into the same power strip. I know this amp is very old, so do I need to replace any of the capacitors, and if so which ones? It sounds like a grounding hum, so is there something else I need to do with the new input to connect grounds or something? I used the metal washer and nut that came with the Fender input, just like all the other jacks on the same amp use.
Thanks for any ideas and experience you have.
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