I'm trying to figure out if there is a program that can be used to compare the audio quality of two MP3s of the same song?

The reason is that I used to rip my CDs with a crappy ripper and encode to MP3 with a crappy encoder. Now that I use better software, I'd like to re-rip everything. The problem is that I don't want new scratches on older CDs to create "pops" on what should be higher quality files.

So the question is: is there a way to detect audio defects from new CD scratches between two versions of a song?

Or maybe another question would be is it more desirable to take a chance and re-rip everything in the interest of higher-quality sound, and at the same time, possibly introduce a couple of extra defects?

Or even better, is there a ripper that can prevent defects from CD scratches using some sort of interpolation?

Cheers,
Jason

If you use EAC in secure mode for the ripping you can be 100% sure that if no errors are detected there will be no pops, or any audible errors at all, in your rips. If a few tracks fail you can keep the old copies or try to get a better result by using burst mode on the failed tracks and listening for audible problems on them afterwards.