Doug Hammond's Pentode Driver

[frickecello]

Hi I'm planning to build Doug's pentode driver I found the 6AK6 tubes from a valves specialty store, they are GE valves.
I will have the board made by a prototyping machine located at the electronic design center at the university where I study.
I want to solve the pedal's known issues, so if you already had good or bad experiences with it please let me know.

Best regards!

[Doug_H]

The biggest issues I've had with it are noise (hum) & compression. I suspect the noise issue could be solved by using a DC power supply. I don't know why it compresses excessively, maybe the screen circuits need to be regulated. The compression makes it feel & sound great at home, but it will disappear in the band mix.

Have fun.

[frickecello]

Have you tried to place the transformer away from the circuit? how about using trimpots to regulate the screen circuits? you suspect noise from the AC valve heater supply?

[Doug_H]

Have you tried to place the transformer away from the circuit?

The transformer is placed away from it, as it is a wall-wart.

how about using trimpots to regulate the screen circuits?

That won't regulate the voltage. If my suspicion is correct, it needs regulation to stiffen it up.

you suspect noise from the AC valve heater supply?

Yes.