Here's what. Guitar, guitar, bass, drums. I don't remember what the bass player was using, but we were playing sort of cleanly. Just our little blues jam. I'm guessing his master was all the way up and the channel was on 4(ish). There was no volume war, we were at gig volume and I just turned up what I had to match the mix. Mix judged by his ol' lady and the bassist's gf. On a technical note, you do realize that there is only 6db difference between a 25 and 100 watt amplifier, yes? I have no idea what the JCM uses for speakers (it was stock, he's a non-techno person). My DR probably had a Eminence 12ALK in it at the time, about a 96 db/1watt speaker. Celestions in the JCM would probably be a close match at 97db/1w. The two amps were fine together, although his had much tighter low end "thump", as would be expected. I remember this very clearly, as I offered to go get my 2x10 Bassman "combo" I put together, and that was nixed so I just used the DR, and was amazed and pleased.