What Does A USB to SPDIF Converter Allow?

If you already have a USB DAC that also has a S/PDIF input, you can usually improve the performance by using a good outboard USB to S/PDIF converter. Most USB DACs have poor implementations of USB interfaces. A good 1.5m long S/PDIF cable is required. The better the cable, the better the result. Also, the better the power supply for the USB converter, the better the result.

Steve N.
Empirical Audio

If you already have a good quality DAC (or CDP with DAC inputs) but either
a. the DAC didn't have a USB input or
b. the USB input was an older (synchronous) system or only ran up to 48kHz or 96kHz

a good USB-SPDIF interface will allow you to continue using your favorite DAC but upgrade the USB connectivity

Not all USB-SPDIF interfaces sound the same though.

The good ones I have heard are the Wavelink HS and the Offramp 4 (now in v5). My friend likes the Bel Canto REFLink a lot too. The Berkeley Alpha USB is also highly rated. I have not heard the last two so can't proffer any real recommendations.

Thanks for the info.

Most of the USB converters I know of have only usb inputs. You would not be able to use them with a transport unless the converter had optical or digital coax inputs. I think the synchro mesh by empirical audio will do what you want, re-clock the signal from a transport and output that into a DAC, but it is not a USB converter.