In order to combine my digital audio devices together, I needed a 2m fiber optic cable. The music source is a CD cover, which is provided, inter alia, with an optical Toslink connector. The music recording takes either a portable MiniDisc recorder (with 3.5 mm optical digital connection) or an MD deck (with optical Toslink connector).
However, since the fiber optic cable is designed for two optical Toslink jacks, I had to find a suitable Toslink adapter for portable MD recorder yet. Both the fiber optic cable as well as the selected here 3.5mm Toslink adapter, are sufficient for high-quality music recordings!