[Mauricio]

More and more, manufacturers are offering USB-to-SPDIF converters.  The idea is that instead of feeding your DAC a USB signal, you can now feed your DAC with a presumably better signal via SPDIF.  A related idea is that most DACs have better SPDIF controllers than USB controllers so that the output sound will be better when the input signal comes in via SPDIF.
 
Is there any merit to all of this, or is it the next snake-oil obsession?  My DAC has async USB, upsampling of all input signals and high bit-rate/sampling rate capabilities.  Why would I ever need a USB2SPDIF converter?

 

[stokitw]

I think the most important feature for USB-to-SPDIF is to take advantage of async usb.
 
If your DAC has async usb already, USB-to-SPDIF could only help if you want to connect two computers to your DAC and enjoy async usb on both of them.

 

[DaveBSC]

Quote:

More and more, manufacturers are offering USB-to-SPDIF converters.  The idea is that instead of feeding your DAC a USB signal, you can now feed your DAC with a presumably better signal via SPDIF.  A related idea is that most DACs have better SPDIF controllers than USB controllers so that the output sound will be better when the input signal comes in via SPDIF.
 
Is there any merit to all of this, or is it the next snake-oil obsession?  My DAC has async USB, upsampling of all input signals and high bit-rate/sampling rate capabilities.  Why would I ever need a USB2SPDIF converter?

Ideally, you'd want to go straight from USB to I2S inside the DAC. Having to use an extra cable and convert to S/Pdif (a fundamentally flawed format) is not desirable in and of itself. Whether a converter will beat a direct USB connection to a DAC depends on how well that connection was designed and implemented. USB DACs with the off the shelf PCM270x chips will be easily beaten by pretty much any converter. If the DAC has an asynchronous input, it depends. The input on the W4S DAC-2 for example does not have a reputation for being all that good. I've also heard that the ARC DAC-8's USB input is less than ideal.
 
Others like the Empirical Overdrive should be able to match or exceed the performance of any USB converter. Steve from Empirical believes that there's no need for the Off-Ramp when using the Overdrive.
 

 

[Roseval]

An obvious first is that traditional DACs have a SPDIF input only.
A lot of PCs don’t have a SPDIF output.
As a consequence there is a market for USB > SPDIF converters.
 
The “problem” with SPDIF is that the timing is derived from the bit rate.
This is generated by the clock of the sender.
If this clock is poor, you have tons of input jitter on the DAC.
How many PCs are equipped with a top quality clock driving the SPDIF?

 

[bixby]

yes it is snakeoil!
 
Just kidding, the respondents stokitw, roseval, and davebsc did a great job telling you why they exist.
 
What dac is it that you use?

 

[Mauricio]

Quote:

hey exist.
 
What dac is it that you use?

 

[bixby]

Looks like a nice dac.  I have only heard its predecessor though.  

 

[Mauricio]

Yeah, it's pretty decent, and a very good value for what you get, I think...

 

[leeperry]

One thing's for sure, the XMOS chipset when properly implemented sounds a million times better than a Tenor TE7702L jellybean...whole different ballpark here, no wonder all the best DAC's are using it as you're only as strong as your weakest link 

 

[ninjikiran]

Based on my testing (Three different USB implementations and two different spdif setups in both optical and rca) the best thing you can do is get a good sound card with a strong asio driver.  It is generally universal, and will consistently work better.  Whether you do optical or rca.
 
The USB chip in the maverick D1 was terrible, the USB chip on the NFB-2 was fine, the Halide Bridge was perfect.  The juli@ sound card is perfect and is a little better than the Auzentech Prelude.
 
 
Assuming your running a Windows or Linux based modular PC.