Marantz MM7055 5 Channel Home Theater Power Amplifier Even with the advent of 7.2 and 9.2channel surround sound systems, most home theater lovers still opt for triedandtrue 5.1channel sound. Recognizing this reality, Marantz built this 5channel power plant as the primary companion to its AV7005 preampprocessor. You won't have to buy more amp channels than you need, but you can easily add one or more MM7025 2 x 140watt amplifiers to your setup for more surround channels or multiroom audio. Behind the MM7055's elegant facade lies a muscular, yet refined currentfeedback amplifier design that excels at reproducing both fine musical detail and hairraising transient peaks.