bikerider1001 wrote:

It seems the consensus is that AIFF is the ideal digital audio format.

AIFF is uncompressed digital, as on a CD. As you are using iTunes, you can save 40-50% in hard drive space by ripping to Apple Lossless (ALAC) without taking a hit in sound quality.

bikerider1001 wrote:

However, looking back through my iTunes collection, I see that most of my tracks are in MPEG-1 format (circa iTunes v3 and v4).

MPEG, or MP3 is lossy data compression, ie, depending on what bit rate you use, you discard musical information. See my article on this subject at www.stereophile.com/features/308mp3cd/index.html.

bikerider1001 wrote:

I did two quick tests: I used iTunes to convert one track to AIFF (Horowitz in Moscow) and I re-imported a Strauss track using iTunes 11.1.3 in AIFF format, all settings auto.

You don't say what bit rate your MP3s were ripped at. If it was 128kbps, then there will indeed have been a loss in sound quality. If it was the maximum of 256kbps or 320kbps, then the potential loss of sound quality might be inaudible much of the time on some music.

bikerider1001 wrote:

A less than ideal, seat-of-the-pants comparison seemed to indicate little, if any difference. And when I say less than ideal, I mean poorly place Klipsch KG2's driven through a Sony A/V receiver via AppleTV.

If you can't detect a difference on this music, then that doens't mean you won't on other music or on a more revealing system.

bikerider1001 wrote:

Does anyone have any comments or suggestions? Or should I just go blissfully on my merry way?

Personally, I would rerip my collection to Apple Lossless, knowing that that would eliminate any possibility I would hear sonic degradation in the future.

Thanks for posting.

John Atkinson

Editor, Stereophile