Allan, in my opinion, a digital-to-digital copy should be an identical clone of the original, which is why the SCMS was developed. You can copy an original, but you can't copy a copy.

As far as media differences go, I could imagine that a high number of drop-outs could exceed a players ability to interpolate midding data, which could lead to an audible difference.

It's also possible that a high-speed digital copying process causes data losses, which results in distortion sounding like excess-compression artifacts.

In short, unless proven otherwise (to me), a digital-to-digital copy will not be discernible from the original. From the reviews I remember reading, digital copies are identical.

Larry
www.fineelectricco.com