Would it be possible to bypass the built in 120v power supply and power the amp using dc(battery). I assume it would be possible, but want to see if anyone else has done it. Using a Soundtown STPA-G500DSP
Parts seem to use 3v and - +12v but i cant say for sure without poking around on it… Carefully
It really depends on the IC that is doing the work. I would bet money the IC is getting more than 12v from the power supply. You’d need to see what it’s getting by measuring it with a multimeter after you ID the pins for vcc and ground.
There are 2 x 3300uf 80v caps there. That tells me that it is a high voltage 70ish volts + & - power supply. There are probably other voltages there as well. Batteries are possible but not sensible. As others say a decent inverter or cheap car amp are probably a better option.