JVC 4DD-5 CD-4 decoder

 
From about 1974

Click on picture below for data sheet
Here is the circuit diagram as a PDF.

Front panel

Rear panel

Top view

Some data measured with Rohde & Schwarz UPL02:
THD at 1 kHz with 10 mV at input

IMD

DFD - not so good.

Frequency response - RIAA. Falls rapidly above 15 kHz due to decoding.

Noise floor linear, 0 dB = 1,3 Volts output

Noise floor with A-filter

And here is the instruction manual