Anyway...when I used mine, I used the clean channel (#2). I found channel #2 was too dirty for Weir, however, using channel 2 without a power amp wasn't loud enough. Maybe I needed to boost the signal before going into the Boogie?
MK, If you used Input 2 on the Boogie Mark 1, and it wasn't loud enough, there was something wrong with your Boogie!!! By the way, that is how the original Mark 1's had two channels, there was no Channel Switching back then. If you wanted the Hot "Santana" deal you plugged into Input 1, if you wanted pretty much a pristine Fender Clean tone, (and these NAILED that Fender Clean) you used Input 2.
When the Mark 2 came along in late 78, you could then get a footswitch (or pull a pot) for channel switching.
Boogie's are stupid loud. even the 2 x 6L6 60 watt versions are just about as loud as an 80 Watt Twin. Randall Smith knew how to Milk those tubes for all they had!
If you had a 4 x 6L6 100 watter, forget it...
My mark 2a starts peeling paint at Master Volume at 3! And that is the clean channel. If I add the Gain Master to it I havent been able to get that past 1.5!
.......................................................have you heard the one about the yellow dog?