Logitech Duet sonds awful

It's not the digital wireless transmission most likely unless perhaps you have a bandwidth limit set on squeezeserver (not the defaultqhich does not set a limit). This might be done to avoid rebuffers that might occur if your wireless network were a bottleneck. That would only likely occur though if you had multiple squeeze devices streaming concurrently or others were using wireless bandwidth for other tasks concurrently, and/or if there is a weak signal between either server or sb and router.

Realize that the job of any network with a music server is merely to transfer bits fast enough to keep up with real time play of music. Data transmission itself across any network, wireless or otherwise, has absolutely nothing inherent to do with sound quality, which is 100% determined by the combined process from the player (sb) to dac to amp to speakers. So the problem is most likely there somewhere, assuming aso that you are getting accurate rips to disk. What CD ripping software are you using? Make sure also that nothing unexpected is happening there. Some ripping software is designed to enable faster rips by reducing rip quality using error correction techniques that might adversely affect sound quality.

Seemingly contrary to the logical explanation above regarding wireless data transfer, I have found with my SB Touch that using it hard-wired, via ethernet, does sound better than using it wireless. Sorry, I have no explanation for that, it's just what my ears are telling me. That said, I agree that bandwidth limitations are not the culprit. That would manifest itself in the form of dropouts, not a change in sound quality. I'm not sure I understand your explanation - what did you mean by "both digital outs"? The SB units only have a single SPDIF/RCA digital output. what is the other?

Also check out the SQB forums for the "best" settings for Squeeze Server to make sure the data conversion to PCM is not happening at the Duet but in the full blown Squeeze Server software on the computer where the wav files are3 stored.

"I have found with my SB Touch that using it hard-wired, via ethernet, does sound better than using it wireless. Sorry, I have no explanation for that, it's just what my ears are telling me."

If so, I am at a loss for an explanation.

I do know as I mentioned that squeezeserver can be configured to operate at a bandwidth limit if explicitly configured that way. But not by default I am pretty sure. I would check to see if this is the case. Even if so, I do not think the server is designed to apply any lower resolution transmission rates automatically based on connection type. Of course, anything is possible when computers and programming is involved. Could be an undocumented "feature" to avoid annoying rebuffering. I don't think this is the case but not beyond the realm of possibility.

I will stick to my assertion though that a wireless connection alone does not mean lower quality sound. Teh devices and software using the connection would have to be the culprit.

I don't doubt you hear what you hear. Sounds better in what way? Are you doing immediate a/b tests when you hear this?

I suspect it is due to some other difference associated with each configuration, though not certain what that might be. Is the physical location of the SBT the same in both cases? I would tend to go with a wired connection if so in general for bandwidth reasons, but I would not expect a difference in sound.

Marco (Jax2), the Duet apparently provided an optical output, as well as a coaxial digital output.

Shlibotnik, did you mean that you had both outputs connected simultaneously, or that you tried them one at a time, with only one of them connected at a time? If you had them both connected simultaneously, it seems conceivable to me that crosstalk between the two inputs within the DAC (after the optical input is converted to an electrical signal) could have degraded the sound due to its impact on jitter.

Also, if possible try a different cable length for the coaxial connection between the Duet and the DAC. The relation between coaxial cable length and signal risetimes and falltimes (which are almost always unspecified) can affect jitter significantly. See this paper.

And are you sure that your rip settings in iTunes were correct, including use of error correction? Also, as far as I am aware iTunes is generally not recommended for high quality rips and/or playback, especially if it is running on a Windows-based machine.

I wouldn't absolutely rule out the possibility that the wireless link is somehow causing the poor sound quality you are hearing, but I would look elsewhere first.

Regards,
-- Al