Music from hard drive better than CD?


Hi folks, I'm considering to buy a MacIntosh G5 for using it as a source in a high quality audio system. Will the Mac outperform the best CD-transport/DAC combo's simply by getting rid of jitter? It surely will be a far less costlier investment than a top transport/DAC combo from let's say Wadia or DCS, hehe. What is your opinion?
dazzdax
Hey Ghunter - I have a question for you about the i-Tunes settings: Can you explain further the "Use Error Correction" setting. I've had it checked, but always wondered just exactly what it was doing. I was under the impression that it only kicked in if there was an error in reading the CD being ripped, and not so much in the frequency for instance. Once the music is ripped to the drive, checking the error correction would have no bearing on playback, correct? I'm learning this stuff too, so your clarifications are much appreciated.

Nickway - you'll use up that 80mb drive pretty fast for uncompressed music, especially if it is holding your OS as well. I'd guess 80mb would only hold about 140 music CD's if there were nothing else on it. Once you figure out what's going on with your set up, I'd encourage you to do a comparison between your uncompressed .WAV or AIFF file and a compressed Apple Lossless file which takes up half the space. I'm not claiming golden ears, but I certainly could not tell the difference. I've read reviews (I think one may have been by Gordon Rankin either on AA or the Wavelength site), which confirm Apple's claim of a bit-for-bit reproduction of an audio file using Apple Lossless. I noticed Empirical Audio ranked them differently. I'd give it a try yourself and see what difference it may or may not make to your ears. Let us know too!

Marco
Hey Jax,

The 80 gig drive is just for music. My system and files are on another drive.

My power mac is not hooked up to my stereo. I just use it for listening when I am on the computer and for loading up my ipod. My computer speakers are Monsoon Audio's, which were made under license from Eminent Technology. I also use my Grado 225 headphones.

I tried using listening for differences between Apple lossless and AIFF with my ipod and my Grado's and I could not tell a difference. I could also not tell the difference between them on my computer speakers.

I can tell the difference between AAC and AIFF. I find that if I must use compression AAC at 256kbps is much better than MP3 of the same bit rate.

On my main stereo I might be able to hear the difference between AIFF and Apple lossless. I will have to give it a try.

Also the 80 gigs just hold my favorite music for loading up my ipod. I have about 400 CD's (and growing) so there is not room for all of them.

Also my Parasound (CEC) 2000 belt drive transport came in this morning. I was using it over lunch and initial impressions are really good. It's very smooth and has plenty of dynamics. I did find that an after-market cord made a big difference. I can't wait for tonight so I can listen more.

Cheers,
Nick
Using error correction when extracting information from a CD is just an extra level of validation that you're getting a bit-accurate copy of the media. It takes longer, but worth it when you're looking for the best possible reproduction. You can think of it as a second scan of every ring, and you're right in thinking it has nothing to do with playback.

Apple Lossless Compression is bit-accurate and just involves a storage compression routine. Compression has gotten a bad rap from the audiophile community (sometimes for good reason) because of the inherent loss in mp3 and other compression schemes. When ALC tracks are played back, you get the same 16-bit 44.1 KHz signal that would be coming from a cd or wav/aiff file. Just like using winzip or stuffit to compress a Word document then uncompressing it later.
Ah, thank you Ghunter. That explains the extra time it takes. So it's essentially double-checking that the data read on the first scan was correct, and if not, I assume it does a third and possibly a fourth till it gets some consistancy? Other than the possibility of actually missing some data, or adding some that isn't there, such an error as error-correction seeks to correct would not be an error that effects overall PRAT, as Nickway seems to be experiencing a problem with..true? In other words, the error-correction is not going to help with a frequency mismatch - wouldn't that be a function of the interface/communication between hard drive and card (in this case the Mbox), and DAC...or, alternatively, harddrive and DAC depending upon your set up? If the harddrive feeds the data at something less than 44.1KHz are the components downstream able to correct for that using a unidirectional connection such as S/PDIF, or Toslink? Or am I mistaken? Is there information sent with the data/signal, that tells the receiving end at what frequency it is sent? Sorry if my questions are pretty fundamental, but I'm just trying to understand all this stuff better.

Marco
Marco, for someone who's learning you've got a pretty good grasp of this!

What you're talking about here is also known as jitter. Here are a few articles that explain what's going on:

http://www.soundonsound.com/sos/Apr03/articles/digitalclocking.asp

http://www.benchmarkmedia.com/appnotes-d/jittercu.html