I wonder what Stan would find if he was to measure the input sensitivity or rise-time of the digital inputs when the circuit is running at these two voltages??????
I doubt we'd have these troubles if what came out of the digital outs was a perfect squarewave shape.. I remember seeing the wave-form of some early players and they were awful - sloppy rise and tons of edgy ringing. No wonder early players had timing/jitter errors.....

