Audio Research Reference DAC and Exclusive mode

I wonder if someone can help. I’m struggling a bit with set up. I am running Roon through a Mac mini connected via USB to an ARC Reference DAC and Media Bridge. I don’t have many high res files but notice when I enable exclusive mode, a AIFF 192/24 file seems to be down sampled to merely lossless. The signal chain light is white and not blue. I’ve tried as many combos in the settings as possible. Also, on disabling Exclusive mode, In the signal chain, I note the blue high quality indicator is only against the System Output (OS Mixer). The source file has what ,looks like a purplish square marker - indicating just lossless? Im by no means familiar with computer audio and jargon and am concerned I’m doing something wrong not getting the best from my system. I should add I can’t discern any audio difference with or without Exclusive. Thanks.


If downsampling is occurring then the signal is no longer bit perfect as part of it now missing.

For Roon to be downsampling it must believe your DAC is not capable of supporting the files native samplerate. Though looking at the DAC’s spec. it states upto 192kHz via USB.

So either the DACs not negotiating with Roon correctly or the max samplerate has been capped.

Can you post a screen shot of Roon’s audio setup page for this zone.

Note exclusive mode by passes the OS mixer, which is better for AQ as the mixer can do horrible things that affect AQ.

Lossless (Purplish-White) is the highest quality indicator displayed in Roon. This means that Roon is passing the original signal on to the audio device without doing anything that could conceivably harm to sound quality.

High-Quality (Bluish-green) is one notch below. This indicates that the audio is being modified somewhere in the signal chain, but that the processing is of a high quality.

The Low Quality (Yellow) light indicates that something nasty is happening in the chain. Lossy file formats like MP3/AAC, and asynchronous sample rate conversion (sorry for the jargon) are the usual culprits.

If you’re getting the purplish-white light, you’re doing as well as you can possibly do with your hardware + Roon.