DIY TOSLINK to SP/DIF converter

Given the variety of… uh, non-traditional hardware that’s connected to my home theater, I’ve found the ground isolation provided by optical TOSLINK connections pretty handy. After poking around a bit, I found a stand alone coax to optical converter. It uses a hex inverter to convert the signals to TTL levels, and a Sharp (or toshiba with some extra components) optical transmitter.