The Amp Garage

This question would probably be better in the Technical Discussion area.

I realize this is a very old thread, however I am experiencing this symptom with an old 52 Fender Super. I'd like to solve the problem, and my first instinct was to replace the volume pot, until a few minutes ago: the amp has 4 inputs, 2 instrument, 2 microphone, as distinct 1st stage 6SL7 stages - ...

BTW, if your amp is on and turned up, with a cable in the input, and the guitar unplugged, you should get a very big noise, if everything is working right.

Sounds like it will be something related to the power supply. I would seriously look at the ground issues. Next, I would be suspicious of some component or part of the circuit that is acting like an antenna.

Based on what you are suggesting, I guess it would be a good idea to check the plate current directly in line, and rule out a problem with the bias probe.

I'm still a bit mystified about that amount of idle current. Will the 6v6's tolerate that?

Thank you!

Also, I did replace the cathode bypass cap, just in case there was a leak.

BTW, thanks for the tips!!

I thought about re-wiring the heaters. Can I just, detach the ground side and go straight to the filaments, then float each side of the 6.3V heater supply with 100 ohm resistors?

Can I determine the amount of ripple on the power supply without an oscilloscope? It's true that 20uF is the value of the first (and other power supply caps, but that is how the amp was designed, and I've played thru other similar amps that don't have this much hum. I'm using an old bias probe that ...

I am attempting to service a very beat up old Fender Deluxe 5B3 chassis, and I'm a bit surprised by the idle current thru the 6v6 power tubes, which as measured via my old bias probe, is about 60mA for each tube. The V from cathode to plate is about 350, cathode to ground is 20 with a 250 ohm resist...

Does anyone have a schematic for a Demeter TGA-2 Inverter amp?
I recently swapped for one, and as it's been modded, I'd like to see what was changed, and who knows, maybe even put it back to original, just to check it out.
Thanks,

Ken

Sorry, I don't mean to get all OCD on you guys.

I do appreciate the chance to ask a few questions that are probably obvious to many on this forum.

To see if you can check for leakage in-circuit, examine the schematic. In most cases there is high voltage DC on one end and a path to ground through a relatively large resistance on the other. These you can check in-circuit. If one end is grounded, then you will have to lift it. Yep, that's about ...