MBA project - audiophile computer transport

I think your initial concept is good, but here's the issue: what makes it sound better? The increase in media servers says to me that yes, there is a market for a good machine that export the data "perfectly".

Here are some of my experiences thus far. Lossless itunes sounds better than lossless wmv files--why? I have no idea. My ipod going from a Wadia to a DAC sounds better than a PC with the same files going into the same DAC (SPDIF). In fact the ipod (these are lossless files) sounds just about imperceptible to the CD that was ripped. Going from the computer there is a very noticable loss in fidelity. It's still very good, but not as good. I've also tried a Genesis digital lens between the computer and DAC to see if cleaning up some jitter would improve the results. Sounds a little better that way--still not nearly as good as the CD.

So, for what it's worth, I would like a PC based computer that would play WMV (lossless but compressed) SPDIF out to a hi-res DAC that sound as good as the CD originals. I don't know if this is possible--in thoery it seems like it should be, but I am a far step away from it at the moment.

Rives - you are comparing apples and oranges IMO. Now if you had a low jitter bit-perfect digital computer source and compared it to the same track playing on a Transport, not a CD player, then you would have a valid comparison. Digital Lens is old technology BTW. There are much better clocks now. You also need an excellent DAC and preamp to hear the differences. The computer should trounce your Transport.

As for a S/PDIF out of your laptop to a DAC, a modern reclocker can make it as good as a transport, even better. See this review:
http://www.positive-feedback.com/Issue39/ramblings_computer.htm

Steve N.
Empirical Audio

Steve:

Thanks. I guess my question now is, how do you get a "low jitter bit perfect digital computer source"? In theory the wmv files should be bit-perfect. They are lossless and on digital comparison once uncompressed should be perfect. So that leaves the jitter and as I understand it there are two forms of jitter. That between the "word" and that within the "words". I know the lens is VERY old technology, but I had it and figured--what the heck.

The equipment is pretty good--I'm a vinyl person, so my DAC is not the best. It's a Levinson 360S. The transport that I compare to is the Levinson 37. Actually--it's quite good for redbook.

The difference I currently hear between the CD going into that DAC, and the wmv files going into the same DAC are pretty huge. The wmv files have a tremendous loss of dynamics, both micro and macro. My main purpose for the server is whole house audio--so this is not some great quest of mine, but if I could improve it and get the lossless wmv files to sound as good as the transport without shelling out a bunch of cash--I would certainly do it. Any additional advice is appreciated.

I haven't read the link you put in yet--but I will--so if my answers are there, sorry about this post.

The wmv files have a tremendous loss of dynamics, both
micro and macro.

Sounds like something is wrong. It might be digital volume control from your
software - digital volume control is notoriously bad - in many cases bits are
adjusted without dither.

Try this: Make sure you computer audio volume is set at max or UNITY gain.

My ipod going from a Wadia to a DAC sounds better than a PC with the same files going into the same DAC (SPDIF). In fact the ipod (these are lossless files) sounds just about imperceptible to the CD that was ripped. Going from the computer there is a very noticable loss in fidelity.

This is very interesting. I don't have any experience with the iTransport, but what Rives is describing suggests -- well, I'm not sure what it suggests, but I do find it very curious. Is he getting better sound because of the iPod (reading the music files off solid state memory?) or because of something the Wadia is doing, or what?