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Wednesday, March 21, 2012

Reverb Ground Loop Fixed

Last night I rewired the grounding situation for the reverb send and receive RCA jacks. Originally I had the ground tied to chassis at that point, like older Fenders I had seen. This apparently had the effect of inducing hum into the reverb amp section, so that every time I turned up the reverb knob, it'd hum like crazy.

I isolated the RCA jacks from chassis ground at that point, using teflon washers on both sides of the jacks, and made sure the "grounding" tab of the jack was on the insulated side, not touching chassis. I then ran a separate ground wire to my ground bus, where all grounds meet up.

Soldered in, cleaned up, plugged in...

Perfectly quiet thick reverb!

 Next step : design a MOSFET high voltage stage for the insertion of my solid state section.

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