[stereocilia]

Does the SPDIF connection from the integrated sound card sound as good and work as well as a usb connection to an external dac?  I'm using Vista 64-bit, if it matters.

Here's why I want to know: I'm considering getting a DAC to connect to a Duet.  In the future, I may want to connect the dac directly to the PC.  So, do I need limit myself to a USB input capable dac?  Thanks!

[henryisland]

Stereocilia,

I use USB in two different setups, with results equal or better than my tube analogue CD players (I use a Stello DA 100 DAC and an AudioNote 2.1 Signature DAC).

The comments I see around say that since the USB is a two-way communication it has the potential for better error correction.  Who knows, but it sounds great.

--HenryIsland

[stereocilia]

Thanks responding; I ended up purchasing a Benchmark DAC1 USB which is now connected to a Squeezebox. Initially, I wasn't sure if the USB option was something worth paying extra to get since I have a spdif output from my sound card if I ever felt the need to connect directly to be PC (without the squeezebox), but when I considered how I might use it in the future I figured it was worth it.  At this point, I haven't compared the usb to spidif, but I'm extremely pleased with the sound of my system now.

[art]

It depends on the mode that USB uses. Some, such as the commonly used adaptive mode, are worse than SPDIF. At least in terms of jitter. Asynchronous mode, which is more difficult to implement, is much better than SPDIF. But few pieces of equipment can do asynchronous.

Pat

[MerlinWerks]

With most USB audio implementations there is no error correction, usb audio uses a different transfer protocol than peripherals like HDD's and printers.
More info HERE...

[art]

That is a good link. Nothing has changed in the 3+ years since it was posted. I only know of one chip that will do asynchronous, and it takes quite a bit of work to write the code for it. Only a handful of products properly employ that chip. There are others that do use it, but in the adaptive mode.

Pat