Re: Mesa Quad Preamp?
The Quad preamp is a GEM from the fine folks at Boogie

It's main purpose was for touring pros in the 80s that would usually use multiple Boogie Mark heads to get the tones they wanted/needed. Boogie's answer to this was the Quad preamp, two completely separate mesa boogie preamps in a 3 rack space, sharing one input. The first channel is *basically* the same as the mesa boogie studio pre once the controls are pulled and it is based on the Mark IIC preamp section. The second channel is based on the Mark III (no stripe/black dot) preamp section.
Both channels offer two modes, rhythm and lead. R1 is TOTALLY huge, fat, warm blackface fender cleans! Seriously, it'll pump out some serious thump in your clean tones with a nice chime. L1 is warm and VERY smooth. If you like that Santana lead tone, there ya go. If you're more into the older petrucci/hetfield tone, kick in the graphic EQ (each channel has a separate EQ that can be turned on/off) and it's instant master of puppets, and justice for all, etc.
R2 is a mode that I personally haven't found TOO much use for regarding my heavy tones. When I'm setup for that, R2 sounds like an in between of R1 and LD1, that is, it's not really clean and it's not really distorted. It's more of a dirty brittle tone....BUT, once you plug in a strat or use passive pickups, it's a really sweet blues rock tone. LD2 has monster gain and serious punch! If you like heavy tones, this mode will surely put a smile on your face.
I really dig the Quad (and studio) preamp because it offers you REAL tone and a good amount of versatility at your feet. You can combine more than one mode at once, which can provide some sweet tones too. At the core, you have 4 different tones to start with. Bring in the graphic EQ and you basically have 8 tones. So really, you can get kinda nutty with it and fine tune your tone rather easily.
If you have any specific questions, feel free to ask
MJ