Vintage Acoustic Research integrated amplifier, recognised among the best amplifiers ever, in original condition, not restored. Original knobs, foot and power cable. Serial number: A017846. Aesthetically is very clean for its age, as shown in the pictures. I run a safe power-up procedure to ensure that the amplifier will turn on with no problems, I took these pictures and then turned off the unit. All knobs revolve smoothly, and all fuses have been checked, but as with any appliance of this age, I recommend a technical inspection before putting it into service. The amplifier will supply any precise and powerful signal speaker system. Features: Output power: 50 watt for channel in 8Ω (stereo) Frequency response: from 20Hz to 20kHz Total harmonic distortion: 0.25% Damping factor: 40 Input sensitivity: 2mV (MM), 200mV (line) Signal to noise ratio: 57 dB (MM), 75 dB (line) Dimensions: 15.75 "x 10.5" x 4.5 " Weight: 22.5 pounds.