Custom replacement headphone cable for SONY MDR-1R headphones. The negative terminals are separated for left and right channels (twisted pair transmission structure) to transmit sound clearly without degrading sound quality. The headphone jack diameters of the MDR-1A and MDR-1R are different; the MDR-1A's is slightly thicker. Therefore, I made this plug specifically for the MDR-1R, and it clicks securely into place. *It is slightly too thin for the MDR-1A and cannot be used. The mini-plug on the headphone side (MDR-1R) is 3.5mm 4-pole, with the following configuration from the tip: Left positive, Right positive, Left negative, Right negative. *This is not a balanced transmission cable. *It is slightly too thin for the SONY MDR-1A and cannot be used. Please use the separately sold cable for the MDR-1A. The mini-plug on the other end is the standard REAN NYS231G (3.5mm 3-pole). MOGAMI 2799 4-core console wiring cable was used. While general headphone cables share the negative terminal for both left and right channels, this cable is constructed with separate negative terminals for left and right channels (twisted pair transmission structure), transmitting sound clearly without degrading sound quality.