物理

How to make your own Sony RK-TXT1 cable

If your first thought is "what in the world is a RK-TXT1 cable" you are not alone, this is a pretty obscure feature. 

A range of older portable Sony MD recorders (such as MZ-R909/R900/R90/R91/R55) when ripping from a compatible CD player could copy the CD Text (like track names) over the RK-TXT1 cable. The cable was sold as an optional accessory and it's really hard to find today.

When I first saw it I thought it must be some cool hi-tech gizmo. Turns out it's just a cable. Here's how to make a bootleg one.

The cable uses the remote connector. The easiest way to make it is by etching a small piece of PCB. 1.2mm thickness seems to be the sweet spot. You will need two, one for each end.

In addition, the connector on the MD-side uses two extra pins. These are not used by regular remotes and sit a bit deeper, in little grooves. You can glue narrow strips of thin PCB (I used 0.6mm) to reach them.

You need only three wires for the cable. Ground, Data and Vcc. The connection goes like this: (Note that the remote jack on my CD player is upside down.)

CD side               MD side
GND   ------------------   GND
Buttons           /------------ CDWM-Data
Data   ---------/          Buttons
Vcc     ---------\         Data
                   \----------- CDWM-2V
                           Vcc

For this to work, you must use the optical cable for audio. Then put your recorder in Rec Standby, connect the bootleg RK-TXT1 cable and start playback on the CD player. If you did everything right, you will see something like this: https://streamable.com/lgbvvz

Only use it with compatible devices or it may put your cat on fire.

I didn't find a list, but these at least are supposed to work:

D-EJ2000 D-EJ955 D-EJ01 D-E990 D-E999

Probably also some other units from around that time.

https://www.reddit.com/r/minidisc/comments/s1iqic/how_to_make_your_own_sony_rktxt1_cable/?rdt=60451