MBA project - audiophile computer transport

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?

"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."

I have to be skeptical here because I've modded a bit of Levinson gear over the years. Very dark-sounding and lacking in extension is the commong thread. The 37 I have modded and installed a Superclock4. This is really stellar with these mods, but not that great without. ALL of my Computer audio devices beat this transport, even with the mods.

"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."

The first problem you have is wmv files. I would use AIFF or .wav only.

Second thing is your S/W player. If you are using a PC, then the only players are Foobar2000 or Jriver. Nothing else comes close IMO.

Third thing is insuring that you are bypassing KMIXER if you are operating on an XP platform. The best way to do this is to unmap the device in control panel-system-devices. I can give you instructions for this if you email me.

Finally, if you are using Vista, then it is critical that you have 24-bit data to get bit-perfect playback, not 16/44.1, but 24/44.1. Only certain devices can deliver this. You must also be sure that the volumes are set at maximum on any player you use and that the sample rate matches between the player, the file and the Vista settings.

There are a lot of pitfalls to getting good sound from a PC, but its certainly possible. No transports (even modded) match the computer audio interfaces that I use.

Steve N.
Empirical Audio

Okay--maybe we are getting somewhere. First, I realize the 360S is not the greatest--but it is consistent for my comparisons. So what is really being compared is the iPod off the Wadia dock, wmv files off an XP computer (yes, please tell me how to bypass the kmixer--this is something I was not aware of--I'm assuming it's in the sounds and I just need to disable those codecs--but I would appreciate the post here--others may benefit from it as well), and the 37 transport. The Wadia dock and the transport clearly best the server. On the server I do have the gain to max--and yes, it sounds like bits are being truncated from lower than max gain, but I can assure you that it is not caused by the volume being set below max.

I do want to stick with wmv files over wav or aiff due to their size. In theory it's lossless, so I should not lose any fidelity if things are done right. I have actually played around with wav files and not found the fidelity to change, so I think the problem is elsewhere.

Another question--would be the SPDIF out. Perhaps a different soundcard with SPDIF? Any suggestions of a reasonable priced one would be appreciated. I can go USB or have plenty of slots to install one in the computer (I assume the later would be better from a transference of data standpoint--but I'm not a computer guru--so I don't really know).

From my perspective, the fundamental problem with PC audio is getting the source file to the DAC with minimal introduction of jitter. Toslinnk, SPDIFF, USB - they all have inherent structural problems. The best use of any of these has been the asynchronous USB approach used by Wavelength and a few others.

What I think is the best path is I2S. Some of the best mods and reclockers involve the use I2S for the transfer of the digital stream (Steve N can vouch for this). PS Audio's new Ultra DAC will use an HDMI connection to pass data in "native" I2S format without a mod. Granted, only their CD player will use the connection immediately, but it's the easy play for the future I think. Sources that can make an I2S connection using an HDMI port will bypass a lot of problems in my opinion.

Now, what I really want is a Sonos box that uses an I2S connection. That would make me happy.

The best use of any of these has been the asynchronous USB approach used by Wavelength and a few others.

Add, this is my opinion. But one I think many would agree with.