Rack-mountable chassis, discrete amplifier design for improved sound quality. Signal input connector six dual RCA jacks. Four-position switch to select stereo, bridged right, bridged left or mono operation for each zone. Independent level controls for each amp channel. Signal link selector two-position switch to link a zone to the signal input connector of the zone to its left (excluding zone 1). Trigger source selector three-position switch to select signal sensing, voltage trigger input or link (to the trigger signal of the zone to the immediate left) to control muting in the zone. Trigger input, euro-style connector, accepts 3V to 24V AC or DC to unmute amp channels in the zone, plug-in speaker termination board. Power switch on front panel, bi-color LED power indicator.