I just picked up an almost mint 1981 jmp 2204 and I honestly didn't know what to expect when i plugged it in. I have a yjm100 and a jcm800 reissue to compare it to. I am blown away by this amp. It is way warmer than the jcm and has the bite of the yjm100. This is my first vintage marshall amp and maybe I just got lucky with this one but no wonder these Jmp's are so well loved. I'm Hooked. The first thing i did when i got it was take the chassis out to look at everything. It does have el34 tubes in it so Im hoping the conversion was done properly. I honestly don't know what the heck I'm looking at but it looks like it hasn't been messed with too much.