Thanks for the answer. As I was in a hurry, I ended up giving up the new board and modifying the original board. Do you know of some way to add a potentiometer of q or voice that works effectively? And gain?
I switched the resistor in series with the inductor by a pot but it does not change the sound at all along the range of the pot.
the mods in the layout should do that. if it didn't work right, i'm pretty sure there's some issues with the build.
the q is controlled by the resistor you mentioned, in series with the 2 legs of the inductor, 0-100k larger = more vocal. the gain is controlled by the cap from Q1 emitter to ground, 0-1k smaller = more bass & gain.