That depends upon how you do your 'actual experience', Peter. I think even more plausible explanations why there might be differences even when going digital out to some external DAC are as follows:
1) Insufficient amplitude or signal strength.
2) Issues with rise times.
3) Poor drive current capability meaning that it's ability to drive capacitive loads is compromised.
Maybe a DAC that intimately derives its clock from the incoming data stream. BTW, where can I buy a $10 DVD ROM?
"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House