Asynchronous USB vs. USB I2S...difference?

[4N6]

Noob questions here. I am just looking to get into computer/server audio. Some servers and DACs have USB output, some asynchronous USB, and others I2S HDMI. What are the differences? Is one style inherently superior? I plan on doing high-res downloads and of course ripping my own collection. Thanks for the information.

[kfr01]

I2S is the native input format for many DAC chips. Native is theoretically ideal in many instances (no conversions required), but computer I2S outputs are very rare and DACs with I2S inputs are also very rare -- such that it really isn't interesting to me. Hey, I like to swap equipment in and out every few years.

It is the DAC, not the server, that needs to be configured for asynchronous USB operation. Here's a white paper from Audio Research that highlights the different major types of USB implementations.

http://www.audioresearch.com/downloa...hite_paper.pdf

State of the art right now is as indicated in the Audio Research white paper:
Asynchronous USB 2.0 HS

[4N6]

Just checking on this, but you really only need the asynchronous USB with a computer as a source, correct? If you had a dedicated music server, there may be other ways to transfer the data just as well if not better?

[kfr01]

By dedicated music server, I assume you mean some sort of specialty device like the PS Audio PWT. Then, yes, there are other good ways to transfer audio data in addition to USB. The PS Audio PWT is a good example of this, as it has an I2S output. The problem is that by moving away from USB, you're really headed into specialty device territory. How many DACs work with the PS Audio PWT's I2S output? Only one or two...

If you want to use a standard computer (e.g., Mac Mini, PC), then go with asynchronous USB.

Edit: Firewire can also be excellent. The Weiss DAC202 (firewire) is a fantastic DAC (see Stereophile review).

[4N6]

I was looking at the Qsonix and Naim servers, as well as the Wyred 4 Sound. Weiss also makes one. However, all are relatively expensive, except for the W4S. The W4S only has coaxial, toslink, and HDMI I2S outputs. This may potentially limit it's compatibility with other DACs, wouldn't it?

Can BNC connectors be used to effectively transfer data (even high res)?

[kfr01]

Originally Posted by 4N6

I was looking at the Qsonix and Naim servers, as well as the Wyred 4 Sound. Weiss also makes one. However, all are relatively expensive, except for the W4S. The W4S only has coaxial, toslink, and HDMI I2S outputs. This may potentially limit it's compatibility with other DACs, wouldn't it?

Can BNC connectors be used to effectively transfer data (even high res)?

BNC are typically just SPDIF.

I agree with you regarding the W4S server. It is clearly built for the W4S dacs having compatible HDMI I2S inputs. This said, a W4S pair might be a bang-for-the-buck champ.