I have no idea what a “Diode Cable” might be. Likely, it is a language translation problem and “dual cable” would be more appropriate. (“Two” — get it?) I once came across a “Blake Lever” associated with the “Stop” button in a cassette deck service manual.

My approach would be to install a Jensen isolation transformer connected to a jukebox line level output. Even better, balance the feed. This will prevent ground loops and handle the extend distance to the main system.

Using a speaker level output will result in passing the jukebox’s power amplifier noise on to the main system.