Hi Rob,
Found this:
Bryston 6B, basic Mono power amplifier, rated distortion less than .02% I.M., rated power 500 watts 8 ohms,800 watts 4 ohms. 19""x5.25"x13.5", 50 lbs. This amplifier consists of two amplifier modules which are combined into either BRIDGED or PARALLELED modes in a 4B sized chassis to form a single high power amplifier to drive very low impedance loads.
james