Power supply: Power range: 12-25V (compatible with most laptop power supplys) Interface：outer diameter 5MM，inner core 2.1MM We recommend using 17-22V power supply. DC12V ------- 8ohm loudspeaker/ 24W x 2 4ohm loudspeaker / 40W x 2 DC15V ------- 8 ohm/36 + 36W.4 ohm/ larger than 60 + 60W DC19V ------- 8 ohm/64 + 64W.4 ohm/ larger than 90 + 90W DC24V ------- 8 ohm/72 + 72W.4 ohm/ larger than 110 + 110W Parameters Color: Black Chip: TPA3116D2 ×2 OP-amp: NE5532P Max. output power: 100W+100W Channel: 2.0 THD: ≤ 0.5% Frequency Range: 20Hz - 20kHz (1 dB) SNR: ≥ 98dB Input sensitivity: ≤ 280mV Terminating impedance: 2ohm - 8ohm Chassis size: 110 x 91 x 36 mm Package include: 1× Power Amplifier Note: Power Supply Not Included