[Randy Myers]

This is true, but also, as important to me anyway, DSD in native can only be sent through the USB connection.  DSD is very important to me and I believe the ESS chipset sounds best with DSD files!

[Russell Dawkins]

toslink supports the highest sample rates than spdif or usb

Reference?

[Randy Myers]

Staright from NuPrime DAC-10H's manual:

Inputs:
• 1 x USB Digital
• 2 x Coaxial Digital S/PDIF
• 2 x Optical Digital S/PDIF
• 2 x Analog Stereo RCA
Outputs:
• Stereo RCA (Line out)
• Stereo Balanced (XLR-3 socket pre-out )
• Balanced headphone amplifier (XLR-4 socket )
• Unbalanced headphone amplifier (6.3 mm jack socket )
• USB Sampling Rates: 44.1KHz, 48KHz, 88.2KHz, 96KHz, 176.4KHz, 192KHz, 352.8KHz, 384KHz and DSD 2.8MHz (DSD64) , 5.6MHz (DSD128) 11.2MHz (DSD256)
• S/PDIF Sampling Rates: 44.1KHz, 48KHz, 88.2KHz, 96, 176.4KHz, 192KHz

As you can see, both Coax and Optical are S/PDIF and can do sample rates up to 192KHz.  USB can sample up to 384KHz and also DSD up to DSD256 (11.2MHz).  Coax is better than Optical because the digital signal is being sent straight out of the player to the DAC for decoding while Optical requires being converted to send across the line and unconverted back to the digital signal prior to being received by the DAC.

According to EJ Sarmento, the genius audio engineer behind Wyred 4 Sound and SST, the original reason that he developed the Remedy unit was because the only output from many Apple units was Optical and it was so poor.  The Remedy was developed to solve this problem and then later Coax re-clocking was added to the unit to give some improvements on this end also.  But he highly recommends using Coax versus Optical if you have the option to do this.  EJ told me this as when he was explaining why you should also use Coax over Optical if your gear supports it (ps... I live near him).

[mr_bill]

Check this out... Could be a real winner according to this review. In a big fan if iFi products and the higher end AMR line they trickle down from. Those dudes definitely know what they are doing. I'm currently still trying to decide if my IDA-8 is actually an upgrade from my iFi Micro iDSD / Parasound ZAmp combo. I'm not totally sold yet, but I almost prefer the sound of the optical out from my Mac into the NuPrime... But reading about the short comings of optical have me second guessing. This little baby could be an answer...

http://www.digitalaudioreview.net/2016/09/ifi-spdif-ipurifier-entry-level-pricing-next-level-results/

- Woody

If optical sounds better then it does. Don't get caught up in the Mumbo jumbo and what is supposed to sound better. I remember using optical on my Logitech Touch as a transport and thinking this doesn't really sound any different than my good coax. I was surprised. I had been brainwashed about reading how toslink is inferior.

[G Georgopoulos]

Reference?

there is no signal loss with optical (compared to copper) and the max speed is almost at the speed of light(only limited by electronics)


as for reference google fiber optics

[Armaegis]

there is no signal loss with optical (compared to copper) and the max speed is almost at the speed of light(only limited by electronics)


as for reference google fiber optics

No, there are potential losses in both, though via different mechanisms.

Consumer grade spdif/toslink also has bandwidth limitations dependent on the material and length of the cable. Depending on the age of the transmitting/receiving end, there are also hardware limitations as the original specs topped out at 48k and "hi rez" wasn't a thing yet.

Fiber optics is not the same as consumer level optical connections for audio. That's a pogostick to jetpack comparison; they'll both get you somewhere, but beyond that the similarities end.