Is USB overrated as decent digital source?

USB is simply a method to get data from point A to point B. It has little to do with audio quality if the conversion circuitry is designed correctly. There are probably lots of poor designs out there, but this is true of almost every type of design, not just USB converters. USB has the advantage that the bandwidth is not limited as much as 802.11G (WIFI), so you can do 24/96 over USB and not WIFI. Also WIFI is limited in compatibility with player software. If you do AirPort Express, then you MUST use iTunes. If you do Squeezebox, then you MUST use Slimserver. There may be plug-ins that allow you to get around this though....

Steve N.
Empirical Audio
Manufacturer/Modder

USB is underrated. I am using a Bel Canto DAC-3 with a USB port. It sounds just as good as a CD as long as you rip with a loseless format, like wma. The DAC-3 set on the USB input sounds better than any CD player I have used or heard, which has more to do with the master clock and TI dacs.

MikeChai - the difference in cost of USB converters is mostly due to four factors:

1) the inclusion of a low-jitter clock, such as Superclock4.
2) external power supply
3) custom software driver (not using the stock Windows driver)
4) optimum design and parts selection, regardless of cost

These four factors drive the cost up orders of magnitude, but also result in sound quality that matches or beats the best transports. It's like the difference between a Samsung $60 DVD player as a transport or an Esoteric.

Steve N.
Empirical Audio
Manufacturer

I see alot of comments about the speed of USB but not enough about all of the pieces. You can certainly choke a PC or MAC with streaming music, as the Hard drive speed, Processor speed, amount of memory, and the USB version all combine. You must consider all of the parts that work in unison. USB has buffers at each end and performs error correction, no jitter that way. You must take into consideration all of the parts including the USB DAC when designing a music system based around a USB DAC and PC.

There are many misconceptions about USB audio.

The speed demands for streaming audio are so slow compared to the rest of the hardware that they have no problem keeping up. Even USB 1.1 is plenty fast enough.

USB for audio uses isochronous transfer and does not have any provisions for error correction. Even if it did error correction has nothing to do with jitter.