Newest 400W Upgraded version of single channel amplifier board 1943+5200 high-power Toshiba transistor rear stage amplifier board. With relay protection The board is a single channel rear amplifier board that requires dual channels. please buy 2 pieces, The circuit design uses the A970/C2240 high voltage audio pair dual differential circuit and A1145/C2705 for voltage amplification, promoting the use of medium power pair A1837/C4793, and the output stage uses A1943/C5200 high-power Toshiba pair. Wide power supply range, DC positive and negative 20V-90V can be used, as long as sufficient power is supplied, it can easily reach 400W. Good sound quality, extremely powerful driving force, driving 15 inch speakers without any pressure!