Should i just try and see if it works, or if im wrong? I am trying to figure out how to change the gain in my hm2 heavy metal. i want alot more.
there is the schematic. i was thinking just replacing r42 with a 22k, so that it could in theory have about twice as much. is this right or wrong?
That will increase the gain of that one stage.
There are other places to increase the electronic gain, not what most guitarists mean by "gain". You could also double (or more) R20, and increase gain in other places before the distortion stage. You could could convert IC1B to inverting gain, which would reduce the amount of undistorted signal mixed with the distorted signal, so it would sound more distorted, even if the gain is actually a tiny bit lower. You could increase the AC gain of Q6 and/or Q7 by splitting the resistor between collector and base in about half, then putting a suitably-sized capacitor to ground to remove the feedback that reduces the gain of these stages a bit.
what should i do so that i don't have to ask questions like this anymore?
Big job. Pretty much you have to go learn how to estimate and change the gain of many types of transistor and opamp/feedback amplifier circuits and be familiar with what the impedances before and after them do to the gain. It takes a lot of time. Some of it's just memory - this transistor stage has this gain and changing *this* by this much increases/decreases it and also does this...
A circuit simulator is a big help in testing out ideas and getting the experience needed to reduce the math to an instinctive feel.