The subject of S/PDIF VS USB DAC is not cut and dried. As with just about everything else, "it depends".
The QB-9 is going to out perform just about any S/PDIF DAC you connect to the Touch. Both the S/PDIF and USB connections on the Touch are really good so its going to depend very much on the details of the DAC. With this USB out a large number of even inexpensive USB DACs might very well sound better than a large number of the S/PDIF input DACs. Strange as it may sound many of the inexpensive USB receivers are quite sensitive to the particular implementation of a USB port. Most general purpose computers have very uneven timing on their USB ports which adds jitter to the PLL generating the local clock in the receiver. While this does not cause data loss, it can significantly increase jitter. The USB port in the Touch has a much more uniform timing so inexpensive receivers will do a much better job than they do with most computers. So a USB DAC that sounds so-so on most computers can sound quite a bit better on a Touch. Then again the S/PDIF output on the Touch is also very good. This makes it almost impossible to make generalizations about which is going to sound better. I have a DAC with very good DAC chips and analog implementation, which has a cheap USB receiver tacked on. When the USB is plugged into all my other computers the S/PDIF from the touch easily blows the USB out of the water, but with the USB plugged into the Touch its so much better that its really hard to tell the difference. A slightly less quality S/PDIF receiver implementation in this DAC would have tipped it towards the USB when plugged into the Touch. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=68346 _______________________________________________ Touch mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/touch
