1 Journeyman 8 months ago Got this old Ampeg Mercury M-12 working pretty well and have been using it on quiet jazz gigs; not that it doesn't have lots of volume. 6V6 power tubes and 6SL7 (octal) preamp tubes; cathode biased. The bright cap has been removed which tamed the harshness of the upper mids. It is very warm and 'retro' sounding; a definite foil to the Fenders and I'm doing my best to embrace the extra midrange. The volume and tone controls are very interactive; when I adjust the tone, the volume also changes, and when I adjust the volume, the tone is also affected. Should be fun figuring out how to take advantage of that. Channel 2 is darker than 1, and it has a stereo option. I wired a mono to stereo jack thinking that I'd use channel 2 for bass and 1 for treble like the accordian players used to do, but it didn't work very well and added noise.