Sony MDR-4T Service Manual

The MDR-4T was a stereo headphone manufactured in 1982 by the Sony Corporation. It had 23 mm dome drivers, and frequency response was 20 Hz to 22 kHz. The impedance was 32 Ω at 1 kHz, and power rating 40 mW. They were supplied with 3 m long cord and adapter plug. This service manual is useful if you need to replace the foam pads, or need to repair them.