Used for indoor PA in a non-smoking environment. Used for about 3 years, 2 hours a week. This digital amplifier is fanless, but it doesn't get very hot. However, for safety, I was cooling it with a 10cm USB fan. I am selling it due to a system configuration change. When the power is turned on, a red lamp lights up, changes to a blue lamp after a few seconds, and sound is produced. The amplifier's Canon and phone inputs both work with the output from the mixer. It has aged, and the performance at the time of purchase is not guaranteed. There are no damaged parts, but there are fine scratches in two places marked with red circles in the third image of the front panel. The marker on the volume knob has been painted black for easy recognition. Power cable included. No instruction manual or original box. It will be wrapped in air cap and shipped in cardboard. Shipping included. The following are the specifications announced by the manufacturer: ■ Type: Stereo ■ Stereo output (4 ohms): 250W + 250W ■ Stereo output (8 ohms): 150W + 150W ■ Bridge output (8 ohms): 500W ■ Frequency response: 20Hz-20kHz ±1dB ■ Damping factor: >400 ■ Input terminals: XLR, phone ■ Output terminals: Binding post (bare wire or banana plug) ■ Power consumption: 288W ■ Dimensions: 48.3 x 4.4 x 24.0 cm ■ Weight: 4.6kg ■ Other: ■ Input sensitivity: 0.775V ■ THD: <0.03% ■ Crosstalk: >60dBV ■ Input impedance: >20kΩ balanced, 10kΩ unbalanced ■ S/N ratio: >100dB ■ Fuse: 7A ■ Output circuit: Class D ■ Protection circuits: DC protection, short circuit, overload protection, thermal protection ■ Power supply: 100V 50/60Hz