[disturbed]

Is there a difference in sound quality of an optical out from a CD Deck and lets say a PCDP. Assume they both don't upsample

 

[geom_tol]

Generally yes.
The decks that actually have an optical out are ususally 'higher' end models, so they have good quality powersupplies and transports.

But to hear a difference it depends alot on what you're going to do with the optical signal next.

Economically it's usually a disaster to use outboard DA converters.

In my experience with external DAC's it's better to use a coaxial digital signal than optical. From what I've read about this there is less jitter with coax connection. But my experience is limited to one DAC only.

I think almost all people using high end external DAC's use some sort of antijitter device, both for coax and optical connections.

So there's alot of extra boxes and cables. A big mess. I don't like it.

 

[Dusty Chalk]

The only thing that could be different is the amount of jitter introduced by the transport. You also may be required to use a different interconnect since most pcdp's don't have standard optical outs.