On Monday I traded my 1986 Marshall JCM800 4210 combo for a 1981 Mesa Mark IIB 60 watt combo with reverb and graphic EQ. The Marshall wasn't really the amp for me. I have a few other amps that get Marshall type sounds that are more to my liking- I like the earlier, non-master type Marshall sounds (though the master in my Avatar 45 makes those sounds more accessible).

I saw an ad on CL on Sunday. They guy was looking to trade his Mesa MKIIB for a JCM800. I've wanted to try a MKIIB for a long time so it was a good match.

The Mesa is a player grade amp. It'll need filter caps (they're all original) and a couple of EQ faders (thought he broken ones still work). The clean sound is really fat and warm. It sounds great with all of my guitars. The lead sounds are great too- a little bluesier than later Mark amps. Unfortunately, it's tough to get both of those sounds with the same EQ settings. The bass setting that makes the clean sound great (1.5-2 on the dial) is too much for chording in the lead mode- though single note soloing sound good. You really have to lower the bass as low as zero in the lead mode and put it back with the EQ.
Fuzz pedals through the clean setting sound great!

I can't get over how much better all of the sounds from this amp sound compared to my Mesa Studio .22. I think I'm going to take the amp to a jam session on Friday night.

I apologize for the low quality pics- it's hard to take good pics in my basement "studio".