Hello,
I just builded that thing, and actually it sounds great, but I can't adjust its gain properly. If I turn the "gain" pot fully clockwise the gain is reduced A LITTLE, and lots of hum is present. However, if I turn the pot fully counterclockwise, the situation is the opposite: more gain, and no hum.
I believe I wired the pot right. I'm using ALPHA pots. The "volume" pot is working properly.
What could be the problem?
I'm going to check my wiring...
I'm guessing that your wiring of the Gain pot is reversed. Turning the control clockwise should INCREASE the Gain.
Is the circuit in an enclosure?
Also, keep in mind that you're adding a fair amount of gain when using the Fetzer in front of the Ruby. Additional gain will often increase noise. My Ruby exhibits some extra noise when playing with the Volume and Gain both at full.
By the way, I'm talking about the RUBY TUBY PREAMP, sorry if I mislead you, I typed it wrong in the title...
Well, the pot was wired backwards, but still I think it's odd that I have no hum when gain is maxed, and very much hum when it's the opposite.
Maybe it's my power supply...
Anyway, I'd like to have less gain. How can I change that?