Played those late 70's to mid 80's Peavey SS amps for several years. Bulletproof!
Sold my last one to the neighbor I got this Marshall from.

Back to this Marshall. The more I play through it the more I like it. Absolutely the most clear and rich bottom response with crystal clear top end in the clean channel. I don't recall ever having an amp with such robust clarity.
In the OD channel, I'm still trying to work my way through the Contour control. Some sort of mid cut/boost insanity that I cannot understand. Just when I think I got it right I'll change from single coil to humbucker and it sounds awful! I'd love to bypass it but the circuits are far too chip dependent. Too far to the left and its "tinny" sounding. 12 o'clock and too loud! To the right and its dark and flat, like a pillow was shoved in the speaker. Just don't get it. So mostly I use a dirtbox in the clean channel and forget about it. Only other Marshall I ever had was a twin 12" 50W SS amp that was great. But I got talked out of it. Money talks... Wouldn't have a tube amp from Marshall. They were my best source of repair income since they were always breaking down! I was glad my customers had em though.