Uses 9volt & 12volt versions of the LM386 chip, 12volt version gives more clarity & headroom, but 9volt version doesn’t like 12volts so beware.....Battery switching is used, so remember to remove jacks when not in use? Possible mods= 1) Removing C3 & connect pins 1 & 8 for a less saturation, 2) Leaving pins 1 & 8 open will give it another dimension. It can also drive a speaker cab like the Smokey amp! Enjoy :)