Using dBpoweramp

It can be both but moStly imperfections in the CD that results in different results in multiple reads used to verify the data when there is no accuraterip data from prior rips by others available for reference. To get an accurate rip in that case, data is reread many times until similar results are produced more than once. That can take a long time depending on how many units on the CD are affected by imperfections. You can bypass the rereading that occurs and tell accurate rip to accept less perfect none validated data if desired in order to make things go faster, but there could be audible artifacts in the rip as a result.

While we are on the topic of dbpoweramp, when is it avail. On Mac?

Thanks Mapman. If there are a lot of frames for re-ripping, I just skip that track and go onto the next one as I have no patience.

Rocky, if a track you really want for whatever reason (for me often to just have all tracks in a release) you can set the bypass in the options after and just rerip the bad tracks to get the best results possible without prolonged rereads/waiting. If defects/bad reads are not extreme, there is a good chance the results will still be mostly good and still quite possibly not clearly audible if not perfect.

I know not perfect rubs many audiophiles the wrong way, but on the grand scale of things the sonic compromises that result may well turn out to be quite trivial compared to many of the compromises in good sound audiophiles sweat about frequently.