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mikeboone
03-09-2008, 06:58 AM
I am working on an amp (Fender Red Knob Twin) for a friend and the reverb has a buzz.

I know why it buzzes, the guy cut the cabinet down to a head and the reverb tank is too close to the chassis. If I take it out and lay it on the bench next to the amp it is fine...

Can I leave the tank unplugged without causing any kind of issue with the reverb circuit being un-terminated? The guy doesn't use the reverb anyway.

Twist
03-09-2008, 07:56 AM
Make sure when the tray is in the amp that the output side of the tray is the furthest from the power tranny. If it still hums then it's fine to take it out. Just remind whoever owns it to leave the reverb level down to avoid hum from the open input RCA jack. There have been rare instances in some amps where you can hear a small distorted signal while playing from the absence of a tray.

mikeboone
03-09-2008, 02:41 PM
I did some reading last night and found a Mod to turn the reverb circuit into a gain circuit.

I used 2 RCA jacks, a 470K resistor, and a piece of coax and essentially put the 470K in series between the jacks.

I was kind of surprized to find that it sounds better than the gain knob native to the amp. It doesn't get really distorted like the gain control does, but its a pretty descent "edged" sound for a bluesy kind of tone.

Thanks for the input...

Mike