This is a beautiful vintage stereo amplifier. It works great. It was my dad's. Here's some details from the internet. The Dynaco SCA-80Q is an all silicon solid state stereo control amplifier of exceptionally high quality. It functions as the control centre for all mono or stereo signal sources, such as a record player, radio tuner, tape recorder, television sound, etc., and provides output connections from two 30 watt power amplifiers for either two or four loudspeakers, as well as a front panel jack for stereo head phones. Thoughtful planning has provided exceptional flexibility with remarkable ease of operation. The SCA-80Q incorporates special circuitry which enables Dynaquad 4-dimensional playback for increased realism from a four speaker system without any additional electronics. Alternatively it may be used as a conventional two channel stereo amplifier with provision for optional connection of a second pair of speakers in a remote location. Specifications Power output: 30W/ch into 8Ω (stereo), 30W/ch into 8Ω (quadraphonic) Frequency response: 15Hz to 50kHz Total harmonic distortion: 0.5% Damping factor: 40 Input sensitivity: 3mV (MM), 130mV (line) Signal to noise ratio: 60dB (MM), 80dB (line) Channel separation: 50dB (line) Speaker load impedance: 8Ω to 16Ω Semiconductors: 20 transistors, 10 diodes Dimensions: 13.5 x 4.25 x 10 inches Weight: 16lbs