Check the listing for details. Heathkit AA-2010 4 channel Quadrophonic Integrated Amplifier. Condition: Used. Listed at 600.00 USD. Another one out of my collection, just been serviced and recapped and ready for some more great years. If you have any questions please ask and thanks for looking. SPECIFICA TIONS NOTE: The following 'specificatlons are typical for four amplifier channels with ldentical signals fed to each channal simulteneously, all channels operating at equal power output into individual resistive loads, and the line voltege constant at 120 volts ac. . Dynamic Power Output per Channel: 50 watts ( 8ohm load). (4 ohm load: 65 watts). (16 ohm load: 30 watts). Continuous Power Output Per Channel 35 watts (8 ohm load) (4 ohm load: 35 watts). (16 ohm load: 25 watts) Power Bandwidth for Constant . 25% Total Harmonic distartion Less than 5 hz greater than 45 kHz. Damping Factor.. greater than 50 Input Sensitivity.. Phono: 2.2 milivo!ts. Tape:180 millivolts. Aux:180 millivolts tape mon.. 180 millivo!ts. NOTE: Input sensitivity is the rms input voltage needed to obtain 35 watts of output power per channel into 8 ohm loads. Input Overload Phono: 155 millivolts. Tape: Greater than 10 volts. aux: Greater than 10 volts. Tape mon.:Greater than 10 volts. NOTE: Overload measurements are made using the input ievel controls. Hum and Noise Phono (10 millivolt reference) -65 dB. Tape and Aux (0.25 vait reference): -75 d8. Volume control ut minimum position: -90 d8 relerred to rated output. Charnei Separation Phono: 50 dB. Tape and Aux: 55 dB or better. Recommended Speaker Impedance (each channel) 4ohms through 16ohms Tape Output Impedance: Approximately 50 ohms Input Impedance Phono: 49 kohms (RIAA Equalized). Aux, tape and Tape Mon: 100 k ohm Tape Output Tape or Aux inputs: 1.4 volt output with .2 volt input. Filter -3 dB at 9 kHz. 14 dB at 20 kHz. CONTROLS AND SWI TCHES Meter Switch (Meters reading 0) 0dB position (35 watts, 8 ohm load). -10 dB position (3.5 watts 8 ohm load). -20 dB position (350 milliwatts, 8 ohm load). Source Switches: Phono Tuner, Aux, Tape, and Mon. Mode Switches: Mono, Stereo, Matrix 4 ch Volume Control: Dual tandem simultaneous adjustment of both channels `Impedance of input connected to tape output should be greater than 25 k ohm