Not much is known about this model.
The accessory CD-4 demodulator for this series is the DQ-3700.
Stereo Bridge Mode
Joystick Orientation/Balance controls
4 Channel modes supported internally include Discrete, SQ Matrix, and SQ Blend
Supports one set of four speakers while in 4 Channel mode or one set of two speakers while in Stereo Bridge mode
4 Channel Discrete Tape Monitor
Magnetic Phono Input
4 Channel Discrete Aux input