C-MarkGA500 mini Class-D / digital power amplifier is a two-channels amp with smart sizelike a dictionary(155 x 387 x 57 mm) only and lightweight of 3Kgs, and up to 7PCS GA500 can be put in a standard 19" rack to make a 14-channels digital amplifier. key spec.: Output power 8ohm: 300W x 2 (1KHz) 4ohm: 600W x 2 (1KHz) Bridged 8ohm: 1000W (1KHz) Free Power Combination from 1PCS to 7PCS in a standard rack as you like, if 7 PCS combined, max power can reach 600W x 14 (4ohm) or 1000W x 7 channel Input sensitivity: 0dB Input impedance: 20Kohm( balance ) 10Kohm( unbalance ) Frequency response: 20-20KHz @8Ω THD+N: 0.01% (1KHz, 1W) S/N: 110dB( A weighted ) Power supply: AC110V or AC220V Fuse cube current: 12A(AC110V) 6A(220V) Net weight: 3Kgs Net dimension (L*W*H): 387 x 155 x 57 mm