Just a quick note to say that Roon works smoothly with the Benchmark DAC 3. No issues for several months. USB or Optical both work fine in my setup.
What are you using for a Roon endpoint, since AFAIK the Benchmark doesn’t have any native Roon capability?
Using a MAC Mini with either USB or optical to the DAC
I used a Mac Mini optical connection with my Benchmark for years. When I tried the Allo DigiOne it was clearly better which surprised me very much.
The DAC 3 is a significant improvement over the two earlier Benchmark products which I have both used. No issues with sound quality and special cables and bridges seem to make no difference with this DAC 3.
I never tried USB on my DAC 3. I have always heard a difference with USB on all other devices including my DAC 1. I’m sure the USB on the DAC 3 is much improved. My Mac Mini is no longer located next to my DAC 3 so I have the bridge otherwise I would still be going directly from the Mini.
DAC 3 is indeed a significant audible improvement over DAC 1. I never tried USB with DAC 1 as my early version of DAC 1 did not support it. USB or optical toslink inputs sound identical in my DAC 3.
Are you sending native file formats to the Bridge or are you performing sample rate conversion? I have had lots of issues with conversion - Apple Core Audio has a lousy sample rate converter. I try to use native file formats without any processing or conversion.
I use native format in ALAC for all my music. I am not surprised the USB and optical sound identical. The advances from the DAC 1 to DAC 3 are huge. It turns out I use ethernet for all my music systems (I just realized that). Probably that has more to do with my being a network engineer for AT&T than any deep audiophile analysis.
Is the DAC 3’s volume controllable via roon?
Never mind, I found the answer here: Benchmark DAC USB Volume