The Rivera has two channels, one American voiced and one British voiced. The American voiced channel can go from sparkling clean all the way up into high gain American sounds, and the British channel can go from barely gritty all the way to searing Marshall crunch. The Brit channel also has a really good Plexi-type setting that is very versatile. There is a lead boost on the American channel, as well as a lead/gain boost that is applicable to both channels (Slavemaster, with it's own effects loop). There is a serial effects loop with send/return levels, a recording out, high/low power switch plus pentode/triode switch, EXCELLENT reverb, all kinds of push-pull knobs to adjust your sound, and more. I have a printout of the manual, which has lots of suggested settings and describes all of the features in great detail. I can also include a schematic for the entire amp, so you can see how everything works inside, as well as a power cord. Inside only the best components are used (Wima caps, Switchcraft jacks, Omron relays, etc) and everything is extremely well constructed.
I would love to trade for your rackmount Mk IV if you are interested, because I have a couple of custom speaker cabinets and would probably have a head cab built for it to match.
