USB vs TosLink to DAC (RME ADI-2 DAC & MacBook)

I am trying out Roon - previously I used Audirvana - so I would like to ask for your help.
My setup is a MacBook Pro to RME ADI-2 DAC via TosLink and from here to my headphone amp.
If I use the TosLink, Roon does not know which DAC I am using and therefore it offers a standard configuration as a default. Is there any disadvantage in using the TosLink connection over the USB? With USB, Roon can identify my DAC and provides more configuration settings (such as DSD for example) than if connected via TosLink.
Thank you.

I think, sometimes TosLink can be limited to 24/96. Also, some people think USB can be noisy. I would use whichever sounds best to you.

I also use a DAC connected via TOSLINK to my RoonCore, and use the settings in device setup to manually define my DAC’s max sample rate and bitrate, DSD settings etc. Works fine!

Thanks, I will try that.

Not everybody agrees that USB is noisy.
Toslink is known as being prone to jitter, USB is async so eliminates that problem, but that’s a red herring, as shown in ASR’s measurements for example modern DACs have solved the jitter problem.

That said, I use USB or IP everywhere, no problems.

USB is FAR superior to Toslink. Higher rates, bidirectional communication with the DAC, etc. The whole “electrical noise between your computer and the DAC” is largely a load of snakeoil. Is it there? Yes? Is it at an audible level? Not even remotely…

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For example, ASR tested your RME ADI-2 and found excellent numbers (-115 dB noise and distortion, -140 dB jitter), and he does all his testing with USB from a PC.

I use the same DAC via USB sounds excellent.

Thank you everyone for your comments.
I tried the RME with USB and with the TosLink and IMO it sounds just as good in both. USB cables tend to be more stiff which makes them a bit less convenient if you run it from a laptop. Sound wise I cannot tell a difference.


This is my findings to , it pretty agnositic of inputs and digital transports.

i use the RME ADI 2 DAC FS too now.
A very fine sounding little box and also good as preamp for my active speakers.
Its connected via digital coax from my Ambre Streamer (has no usb out)
a I2S Input would be top of my wishlist for the RME, with my last DAC this connection sounded best