Nothing - except that any processing would then have to be done in the analogue domain OR the signal would need to be re-converted to digital. Which would then beg the question: why not keep it digital to start with?

We have analogue connections for DVD-A and SACD not because the hardware to play them could not have been first introduced with fully compatible digital connections, but because the powers-to-be are terrified of letting us have access to nice, clean, pure - and potentially copyable digital signals. Better technology will always appear to them as a threat - rather than the opportunity that it really is.

And personally, I have a problem with any power-to-be who tries to keep me in the stone age - relatively speaking.

Jeff Mackwood