Egnater Tweeker 40 NO OUTPUT

[bigdrums925]

Hello: Stumped as to why there is no signal on the plates of the 6L6's when it is present at the control grids. I don't have the schematic but
the measurements with input signal and tubes installed are:
Pin 1 44VDC, 8VAC
Pin 2 3.3VAC
Pin 3 438VDC 0VAC
Pin 4 434VDC 0VAC
Pin 5 -45VDC 19VAC
Pin 6 0
Pin 7 3.3VAC
Pin 8 45VDC 8VAC

Anything look out of line here?

[52 Bill]

Hello: Stumped as to why there is no signal on the plates of the 6L6's when it is present at the control grids. I don't have the schematic but
the measurements with input signal and tubes installed are:
Pin 1 44VDC, 8VAC
Pin 2 3.3VAC
Pin 3 438VDC 0VAC
Pin 4 434VDC 0VAC
Pin 5 -45VDC 19VAC
Pin 6 0
Pin 7 3.3VAC
Pin 8 45VDC 8VAC

Anything look out of line here?

The cathode voltages seem high for a fixed bias amp. What is in the circuit between the cathodes and ground?

[Enzo]

Right, somehow you have +45 on the cathodes and -45 on the grids, so there is 80v of bias, which might be enough to pinch them off. However, it seems unlikely the amp was made that way, so perhaps the ground connection to the cathode is open? That would prevent current flow and thus prevent signal from reaching the plates.

[52 Bill]

Well it is a fixed bias amp with a fuse and a 1 ohm resistor from the cathodes to ground.

Check the fuse.

[bigdrums925]

I can't thank you guys enough. With the pointers and the schematic I was able to chase down the interruption in the path to ground. Of all things it was a trace that was the culprit. Just resoldered the eyelets and whahoo, it's working! Thanks again!