airport express questions

you can't add bits of information that wasn't there in the beginning. if you send 8 bits of info to an airport express, even after all of the codec manipulation, you will get 8 bits of useful information after the AE. sure you might get 24 bits after the conversion, but it will still only be 8 useful bits. for example, once you rip a cd to a low quality format, say mp3, it will always be mp3 quality, you have lost all of the info and will not get it back. sure you can convert it to acc/apll/etc..., but it will always sound like mp3, those compressed/dropped out bits are gone forever.

"but it will always sound like mp3, those compressed/dropped out bits are gone forever." - I agree.

Percisely- I understood it to take it to unpack the alac on the ae side to digital or analog. The point to all of this seems to be that if you are going to use airtunes, there is no point in using any other losslec codec other than alac. I see many people state that aiff/wav sounds better but I don't see how this could be.

I see many people state that aiff/wav sounds better but I don't see how this could be.

I don't understand it either, but I have most definitely heard some high-rez files sound better than others to the point where I could identify the files blind. One possible factor is that the Apple Lossless codec requires processor power and time, no matter how minute, to uncompress the file on the fly. WAV and AIFF do not require any decompression. WAV is native to PC, while AIFF is native to MAC. I only can speculate as what I know about the inner workings of this stuff could fit inscribed on a pin-head.

I also don't know why an interconnect or a power cable might effect the sound of a system, but indeed I've heard them do just that. Come to think of it, there's a whole lot of things in life I cannot explain, or begin to understand.

it will always be mp3 quality, you have lost all of the info and will not get it back. sure you can convert it to acc/apll/etc..., but it will always sound like mp3, those compressed/dropped out bits are gone forever.

I agree that it will always sound inferior to the full-resolution files. But if you convert an Mp3 to an acc/apll/AIFF or other higher-rez version, it will not necessarily sound just like the original Mp3. It may sound worse. If you up-rez a file, the software you use to do that is having to interpolate what bits go in between and fill out the Mp3's existing zeros and ones to create an AIFF file, for instance (which has many more zeros and ones). Those fictional zeros and one fillers are most certainly bound to have an effect on how the file sounds. Could be worse, could be better, could indeed occur to one as unchanged, but it will definitely not be an identical file to the original. I certainly agree that all of the original information that was lost in the first place by converting it to an mp3 is gone for good, short of re-ripping from the original.

Someone correct me here if I'm off base so I can get to work on this pin-head inscription I mentioned earlier.

Jax2 - Stereophile tested digital output of Airptort Express and compared to original uncompressed file they sent from I tunes and they are bit for bit identical with 255ps of word jitter.

APLC does not reduce quality of MP3. There is no missing bits in MP3 (nothing to interpolate) - it has 16 bit resolution. Bits are not lost - the musical information is (simplified). In order to play MP3 it has to be uncompressed first. APLC is decompressing MP3 and then compressing it to APLC format to decompress it to uncompressed MP3 ready to send to s/pdif out. No missing bits.

I have no idea why APLC sounds different to some people. Time to process data has nothing to do with it since it goes thru output buffer. It is possible that people compare sound from different devices like CDP versus computer while not every device is "bit transparent". Some CDPs have digital volume control or some form of DSP processing. In addition Itunes might have volume control enabled as well as equalizer. Finally it might be placebo effect.