Thanks for the replies, I have talked with a couple of techs ;ocally and none of them really seem to know much about the electronics of the hybrid which I found hard to believe with them being techs. Now the resistors you mentioned to change Eddie?  Have you had any problems out of the amp since you changed them? I do fine with simple cap and diode and resistor changes but building circuit boards I have zero luck with and as much as I would like to build the presence control I best leave that alone,,lol.

I have a vintage peavey mace vt series from the late 70`s, the amp that lynyrd skynyrd used and it is a hybrid with 6 6L6 power tubes and a SS pre amp. I would like to mod the pre amp so it packs a little more distortion, would love to have a cross between skynyrds sound and blackfoots sound. Naturally I play southern rock so hence the 2 sounds. I am going to get a shematic on the amp from peavey and would GREATLY appreciate any and all help that you can offer. I know throwing in a pedal is the easiest option but I would really like to stay on a straight plug and play basis if possible.