Are USB to SPDIF converters subject to the same limitations as USB?

[wgscott]

Title says it all.

 

What (if any) benefit can a USB to SPDIF coax converter provide if it uses the USB output from the same computer? Is the difference just the receiving chip in the DAC, or what?

 

(I currently use a Halide Bridge mainly because it is less limited than my USB input, but on a newer DAC the bridge will be more limited, so I am now curious if there is any reason to keep the thing.)

[davide256]

A DAC with built in USB is a better solution... if nothing else it puts the signal to the DAC mainboard directly vs introducing yet another cable interaction. And I believe built in USB is required for native DSD playback.

[joelha]

I respectfully but completely disagree.

 

In every case I have experienced (Berkeley Alpha USB, Mutec, and most recently, the AFI-USB, there was a distinct improvement realized by going through the converter vs. going directly into the DAC. As I understand it, the right device better isolates the DAC from the electrically problematic aspects of the USB signal.

 

Joel

[goldsdad]

I would do something radical: listen with the Bridge, and listen without the Bridge, then go with whichever sounds better to me, regardless of what other people tell me.

 

Or if you really do want the opinion of true golden ears, ask those lovely dogs of yours.

[wgscott]

I would do something radical: listen with the Bridge, and listen without the Bridge, then go with whichever sounds better to me, regardless of what other people tell me.

 

Or if you really do want the opinion of true golden ears, ask those lovely dogs of yours.

 

I plan to try USB, glass optical, the Halide Bridge and ethernet inputs. I'm just trying to calibrate my expectation bias.

 

I even spent $1.50 on a USB cable from Blue Jeans Cable, so as not to compromise the quality of the input.

 

Oh, and most importantly, thanks for the dog complement!

[One and a half]

A DAC with built in USB is a better solution... if nothing else it puts the signal to the DAC mainboard directly vs introducing yet another cable interaction. And I believe built in USB is required for native DSD playback.

 

I would have thought short connections in the DAC would be ideal too. However, USB is toxic to the DAC's supply rails either through packet noise, or just common noise from the USB transmission including hum. For these reasons, it is better to process USB out of the DAC.

 

For DSD native, solutions exist. For now this solution works for me quite well in that HQPlayer upsamples everything to DSD128 and the Mutec MC-3+USB converts DSD to PCM & outputs to AES3 to the DAC at 176.4kHz. I have tried many times to input USB to DAC, but the sound was badly affected by USB transmission problems with the 'familiar' digititis sound.

[Jud]

goldsdad gave a dog compl*i*ment. It is you who have a dog compl*e*ment.

 

Thus endeth (mercifully) the lesson.

[Jud]

My own thoughts:

 

- goldsdad's advice is good.

 

- As usual there are competing factors, and the outcome depends on implementation and on the environment where that implementation will be used, i.e. your system.

 

- The main factors are jitter and fewer connections (in favor of USB) and isolation from noise (in favor of SPDIF). The type of stuff joelha is talking about costs half again what your DAC does, so hopefully it does a better job of isolation than the Halide. Depending on what's more of a problem in your system, direct USB or SPDIF could wind up sounding better.

 

- Usually USB allows upsampling to higher resolutions, and is pretty much the exclusive common means of inputting DSD. If your DAC happens to sound better with music upsampled to DSD resolution/format, USB would be the choice.