SPDIF or Toslink out? Why?

[Tacty]

i use coax because i have audioquest 75ohm coax cable...i don't like tinny optical cables, all of them looks cheap and flimsy...as for the sound, who knows, i stay with my unscientific approach

 

[Math You]

If something hasn't changed, USB audio uses the isochronous real time transfer protocol. It has CRC like the bulk transfer used to reliably transfer data but differently from the latter, in case of error anyway no resending is done.
Probably there isn't a clear superiority for the usb.

https://www.edn.com/fundamentals-of-usb-audio/

If your external DAC has a better clock, using USB would be better as it doesn't need to sync with the wiim ultra. Acting as the master clock source it reduces jitter (timing errors). A!so, not as important, but with USB you always get the max bandwidth possible. Coax tops at 192kHz. Optical usually 96kHz. USB is capable of 32bit 768kHz PCM and DSD512.

 

[Burnside]

USB is capable of 32bit 768kHz PCM and DSD512.

On WiiM devices, I believe the best you’ll get on usb output is 32/192.

 

[Math You]

On WiiM devices, I believe the best you’ll get on usb output is 32/192.

Yes, correct, Wiim ultra maximum on usb is 32/192. I just mean generally usb is "better"

 

[merifon]

If your external DAC has a better clock, using USB would be better as it doesn't need to sync with the wiim ultra. Acting as the master clock source it reduces jitter (timing errors). A!so, not as important, but with USB you always get the max bandwidth possible. Coax tops at 192kHz. Optical usually 96kHz. USB is capable of 32bit 768kHz PCM and DSD512.

I think the only advantage of usb is the capability to carry higher sample rate, even if not so diffused, someone could need to play it. The clock in usb audio is quite sure asynchronous, set by the dac but also for spdif and toslink (capped just on very cheap devices) is the PLL of the input stage of the dac that corrects and sets the clock.
Lab tests usually don't show, so different amounts of jitter when different connections are compared on a given device.

 

[JamesBentley1]

Thank you all for the input and insights. I had not considered trying USB and will simply trust my ears, great advice!

 

[valterdanc]

Audio is brighter with optical connection...

 

[Math You]

I think the only advantage of usb is the capability to carry higher sample rate, even if not so diffused, someone could need to play it. The clock in usb audio is quite sure asynchronous, set by the dac but also for spdif and toslink (capped just on very cheap devices) is the PLL of the input stage of the dac that corrects and sets the clock.
Lab tests usually don't show, so different amounts of jitter when different connections are compared on a given device.

Have you ever seen an example where a DAC has measured better jitter performance with coax or optical? I don't think I have. I get that some ppl don't like usb while using the PC as source because of noise from the PC components, but from a streamer (and as long as it's a reasonably good quality usb cable) it's probably optimal. Especially if the dac also has galvanic isolation on the usb input.

However, whether any of this is noticeable in the majority of cases is questionable.