So, I finally got around to experimenting with stacking my B50R on top of my B100R, and liked it so much I gigged with it last night at an outdoor pool-patio party. Wow. I did just what I imagined it would: It is the killer combo-combo.
Details: I didn't use any effects other than the Sansamp BDDI that I used to split the signal; I sent the effected signal (blended in at about 12:00) into the big boy, and the unaffected signal to his little sister. (I find the BDDI into the 50 a little too much tube emulation, but just the right amount into the 100 sounds great.) I boosted the lows and low-mids a little on the 100 and left everything else on both amps pretty flat. The tonal range was unbelievable, with big fat bottom end from the one, all the highs you'd want from the other, and the overlapping ranges of thick, juicy, tube-y mids from both. I've always thought that the only drawbacks of these two combos are that the 100 lacks a little in the top end, and the 50 lacks a little in the bottom, so there you go.
Another nice benefit was the one on top of the other, I could hear myself so much better than having just one of them on the floor behind me blasting my ankles.
While experimenting with this setup last week at home, I had discovered that if the Sansamp was plugged in, I got a nasty ground-loop hum. Sure enough, as advertised, plugging in one of the amps through an Ebtech Hum-X completely solved the problem. But I also discovered that if I ran the Sansamp unplugged on battery power, I didn't get the ground loop, so I went that route at the gig for simplicity.
BTW, the gig was a blast. We hardly ever play out -- we've always been primarily a just-for-fun garage band -- but we were a big hit. OK, granted, everybody in the audience was seriously hammered, but they had a blast and thought we were the S***. We might've played all night if the cops didn't come shut us down. (We were so proud.) We're gonna have to do this more often... and now I know what rig I'll be bringing!