Lossless Files Vs CD's

I don't hear any real difference generally, but I would give the edge to the lossless files in terms of overall quality consistency and reliability in that they effectively take the error prone real time optical read aspect of playing CDs out of the equation technically.

What are you talking about? FLAC allows you to download 24/192 files from the Chesky website, not wav.

CD playback can only approach (but never really achieve) "bit perfect" reproduction as there is always some error correction going on in real time, unless a "memory buffer" type playback is used to correct any errors in reading data from the CD.

Bit perfect ripping software assures all the data from the CD is error free before it is played back. So conceptually, it would seem that bit perfect ripped files would be as good as it will ever get from a 16/44K CD.

That being said, the playback of ripped files (computer, motherboard, soundcard, etc.) then become the sound quality limiting factors, and they can create just as many variables as the error correction in the original CD deck IMHO.

For example, some say that ripped 16/44K files played though the Bryston BDP-1/BDA-1 sound better than the exact same CD played though Bryston's CD player BCD-1. Some dissagree and claim the CD player is better. I mention this combination because in both the BDA-1 and BCD-1 the analog output stages are similar so only the digital processing stages are different.

But higher resolution 24 bit "lossless" or bit perfect files have more potential than any 16 bit CD file, so therein lies the real value to using bit perfect files.

My understanding is that if a CD is in good physical condition, the main reason why it might sound inferior to playback of a bit-perfect computer file is NOT errors that the player can't correct on the fly in a bit-perfect manner, which would therefore require inexact interpolation. My understanding, based on numerous references I have seen in the past, is that for a disk that is in good condition that will happen rarely during the playing of a disk, and not at all in many or most cases.

The main reason that real-time CD playback may provide inferior results is that electrical noise generated by the servo mechanisms and circuitry in the transport part of the player, as it tracks the disk, may couple into unrelated downstream circuitry in the player, causing jitter in the D/A conversion process, and/or effects on the analog signal path. The degree to which that occurs will be dependent on the design of the particular player, of course, as well as on the condition of the disk.

From this Wikipedia writeup:

Reed–Solomon coding is a key component of the compact disc.... In the CD, two layers of Reed–Solomon coding separated by a 28-way convolutional interleaver yields a scheme called Cross-Interleaved Reed Solomon Coding (CIRC).... The result is a CIRC that can completely correct error bursts up to 4000 bits, or about 2.5 mm on the disc surface. This code is so strong that most CD playback errors are almost certainly caused by tracking errors that cause the laser to jump track, not by uncorrectable error bursts.

Note that the term "error correction," as properly defined in this context, refers to bit-perfect correction. "Error interpolation" is the term used to refer to the less than bit-perfect approximation that can occur (rarely) when bit-perfect correction fails.

And from a post by Kirkus in this Audiogon thread:

CD players, transports, and DACs are a menagerie of true mixed-signal design problems, and there are a lot of different noise sources living in close proximity with suceptible circuit nodes. One oft-overlooked source is crosstalk from the disc servomechanism into other parts of the machine . . . analog circuitry, S/PDIF transmitters, PLL clock, etc., which can be dependent on the condition of the disc.... One would be suprised at some of the nasty things that sometimes come up out of the noise floor when the focus and tracking servos suddenly have to work really hard to read the disc.

Regards,
-- Al

"for a disk that is in good condition that will happen rarely during the playing of a disk, and not at all in many or most cases."

Probably one explanation for why I can't hear a difference in most cases. The eror correction built into CD redbook format is fairly good it seems, but of course there is always a threshold in regards to disk quality and mechanical/optical reader performance/reliability in practice that could make a difference.

It still seems to me that Bit-perfect ripping does provide the best case scenario for reliably getting the data off the optical disk as best as possible still though I would say in that the need to read data in real time with a certain minimum throughput (in lieu of buffering) is a constraint with playing a CD that does not exist with ripping.

THere is still lots that can go wrong downstream from there in regards to jitter in particular even with a practically bit perfect ripped .wav file. More so in general perhaps in the case of FLAC which is lossless but compressed and requires more processing in the D2A conversion process.