any words of wisdom for usb noise problems?

Ckorody,

If you want to experience fabulous digital playback, consider the Wavelength Cosecant. I am able to select and control my musical selections with NetRemote-J. River Media software with a pocket PC using a Wireless LAN. A dedicated power supply would be superior for a USB DAC.

Steve

Yep -saving up for the next great thing... Steve and Gordon both have some nice things to consider =)

For Wkraft - please forgive me if you know this....

The Waveterminal is just a device for converting USB to SPDIF/Toslink. Actually it has a DAC built in too, but I have never seen anyone comment about using one. It was developed and marketed to the semi-pro audio recording market

As a general point of info, USB devices come in two flavors - those that require a dedicated power supply (because they need more juice), and those that can draw their power from the USB cable. In fact the Opticis needs a power supply and what Steve has done is create a DC one instead of the AC wall wart. The U24 is an example of a device that does not need its own power source. But effectively that leaves it connected to the computer...

I would assume that any USB DAC (certainly all that I am aware of besides the Waveterminal) require a dedicated power source, though some (like the RedWine units) are battery powered since the DACs tend to operate at 5v.

to elaborate- the waveterminal running into the coax digital input of my panasonic sa-xr55 (i know many will turn up their noses at this class d based unit) results in dead quiet speaker and headphone output. this prompts me to wonder what in the receiver prevents the noise transmission. i see that most audiophiles are not using the u24 dac function, and i am thinking ahead- would implementing certain kinds of dac obviate the need to uncouple the u24 from the dac.

I have used the Waveterminal for almost two years now. It a a great device but I am sure one f its short comings is that it draws its power from the PC via the USB cable. I have spent a lot of time listening to it as a DAC and it is phenomenally good sounding given its price. I am awaiting one of Empirical Audio's new wirless USB offramps. You can find info at their site.

This is clearly a design fault of the U24. They should have put a circuit inside to clean the power via usb and/or add the possibility to connect the U24 to an dedicated external power supply.

I tried an external USB-hub with it's own external power supply. Unfortunately the U24 isn't recognized by the computer when connected via the hub but maybe this is just a matter of reinstalling the U24 drivers.

I am thinking now of modificating the U24 to make it work with an external power supply. The easiest way is probably to cut the USB cable in two and connect pins 1 and 4 of the part which leads to the U24 to an external power supply.