Should I get an Optical or USB DAC? (Schiit Modi)

[savagebeard]

I am looking to get the Schiit stack (Schiit Magni and Schiit Modi) but I see that there are 2 Modi models the Optical and the Usb (Modi 2) which one is better? I have read that there isn't really a difference in sound quality, but that optical has less feedback? I have a MSI x79A-GD45 (8D) motherboard, which has an optical input so that shouldn't be a problem. This isn't really buying advice, I'm looking for some information about optical vs USB.
Any advice would be greatly appreciated.

 

[americanaudiophile]

Schitt states in the specs that optical outputs are not as reliable for high res audio files (24-176 or 24-192) so that might be a factor is you want to take advantage of the superior sound quality of these larger files.
It's true that optical does potentially isolate the DAC from PC noise but it isn't an issue in real life. You could add one of there
http/hifimediy.com/usb-isolator
if you wanted to in the future. Not as good as the Schitt Wyrd but less expensive.
You are also bypassing the audio part of the mobo which will potentially sound better. Go for the USB or do the Modi2 Uber if you want all your options open

 

[MarcelM]

I own both a Schiit Gungnir (coax, optical & USB) and a Modi (optical). From the start the Modi did not go beyond 24/96 while the Gungnir had no problem with 192/24. Sometimes the Modi does not work at all. I do not have a clue why, but I think it is the optical connection. I prefer coax over optical. Coax always works and it is easy to connect.
I have compared USB with SP/DIF on the Gungnir. SP/DIF has a better sound quality on high end audio systems. USB lacks details in the stereo image and SP/DIF has a better response to very dynamic music, where USB sounds more 'flat'. However, you only hear the difference on audio systems of sufficient quality. Also USB does not work well on every computer. It is OK on my desktop, but when I used it on two different Dell laptops the sound was really terrible. The sound was out of tune.
Summarizing I would go for coax SPDIF or HDMI. However, with HDMI I have also experienced sound quality issues when used with computers, depending on the video card/driver used.