Tobias Growler electronics question

[beelzelboss]

Decided to crack this baby open today, and I find a very complex wiring system. Pretty cool, and then I spotted these. Four white circles, with a slot in it as so it can be changed with a screwdriver.

Anyone got any ideas as to what these four things do?







What do you think they do? And most importantly, should I play with them?

[Anthbass]

Those are trim pots for pre-amp adjustment. I had the same bass and a TB member (Vic) sent me a schematic on what each one did. I can't find my copy, so you might try contacting him. I do recall that the trim tabs are quite sensitive, so adjust minutely, if at all.

[beelzelboss]

Thanks, how do they adjust the sound?

[abarson]

There are two preamplifiers in a Growler, one for each "half" of the pickup. One trimpot on the preamp sets the bass/mid crossover point, while the other sets the mid/treble crossover point. I'll see if I have the documentation on the setup.