MQA over USB?

I searched the forums, did not find what I was looking for. Considering a DSJ and want to understand if there are input restrictions associated with MQA support.

Does the DS/DSJ support full MQA unfolding via the USB input?

Or is it only via Ethernet as the processing is on Bridge II?


MQA is Bridge II only. No MQA on USB. Good luck with your DAC decision.

Thanks for the quick reply.

Note to PS Audio, it would be useful to document the caveats for MQA support in one place. Bits are scattered through the forums and you have to rummage around a lot. I noticed your firmware releases do not include release notes. Coming from a software background, I guarantee you can reduce your support costs by including good release notes, and if you did, this would be a reasonable place to document new features such as MQA.

Robnik33, I agree the notes might be helpful with some updates. As there are many pages discussing MQA, I’ll try to summarize.

Originally MQA required DAC manufacturers to send them their DAC so they could alter it to process MQA, Paul along with companies like Schiit and Benchmark, did not want a second party messing with their carefully designed products. I also know that those three are not fans of MQA, they don’t think it solves anything. Not only is it lossy, but it has already been proven by Quboz that full hi-rez files can be streamed, so it really isn’t necessary. Well, there were enough owners of the Directstreams that wanted the option of MQA, and the original claim that MQA processing needed access to the DAC was changed. Look at Tidal being able to do the first unfold with their software player, then PSA found out they could do the processing in the Bridge II.

As Paul has explained to me and others is that the Bridge II is just another input. By working with the makers of the Bridge II, they were able to add not only a Room endpoint, but MQA processing. That way, PSA can continue to offer firmware updates, without having to send the DAC to MQA. As I understand it, there will be a Bridge III, built in house, that will give PSA full control of the device.

So the bottom line is that the Bridge II is the only input that has the separation and power to implement MQA. The Bridge II converts the compressed MQA stream back to an uncompressed one with the resolution of fully unfolded MQA. There are tutorials that explain how to do the updates, and how to integrate your computer or dedicated player to work with the Bridge. And the customer service people are the best in the business, always willing to help.

If I got any of this wrong, someone please correct me.

Not that I disagree with your points in principle but:

The product description for the DS ( says “Now, full MQA, Tidal (including Masters), Spotify, VTuner, Qobuz, and Roon ready with Bridge II installed.” Granted that may not say “no MQA decoding with other inputs” to everyone but I’d take that as a strong hint. The forums (fora) aren’t the best place to find concise feature documentation. I hope the DS manual (which is available for anyone to download) will be updated with more details about MQA. The release notes aren’t formal but there’s always a new thread announcing a new release with (essentially) the release notes - the first N posts in those threads contain more details about the various features. Paul usually has most of that information in his daily post on (or near) release day.


I agree the information is there if you look in the right places, and know the right places to look. Just making a suggestion as to how you could make it easier for an outsider considering purchasing one of your products. Sometimes it is hard to unlearn all your assumptions to see your product from the outside with a fresh set of eyes. This is not meant to be criticism, merely observations and suggestions.

Regarding MQA, I first looked in the manual (not there yet), then looked for release notes with the version that supports MQA (no release notes), then spent a lot of the time in the forums (figured most of it out but it took quite a while), then asked a question (and got an immediate answer). I did get what I needed, which means you are already performing way better than almost all audio companies! I chuckle about posts where Oppo support swears that they have a feature (ie DSD over HDMI) and they don’t have a clue about how it works! And FYI they don’t support MQA over USB either.

For the numerous semiconductor and software products I have launched over 35 years, I used to tell the engineers “it is not finished until the fat lady writes the manual.” We all want to get new exciting features in the hands of users, and new stuff evolves pretty rapidly, making difficult to document as it is still changing. I would manage it by including an install guide and release notes in the firmware directory and then rolling the information in to the product manual when things settled down. As most engineers would rather go to the dentist than write documentation, I managed to convince them that they would spend way much more time on support than it would take to just get it out of the way.

Kudos to you for continuing to improve the products with regular firmware releases, a huge plus in your favor.

Pulled the trigger on a DSJr to pair with my recent BHK preamp purchase. It arrived with Huron, simple upgrade to Redcloud. Followed the procedure for setting up MQA over Tidal via Mconnect Mcontrol, got it set up easily. Took a while to figure out that the DSJr volume needs to be set to less than 100 to see the left side of display that shows MQA status.

Happily enjoying a huge step up in sound quality, looking forward to getting this baby broken in!

I suppose that it is true that full MQA unfolding is not available via the USB input, however Amarra 4 Luxe does a partial unfold of say a 192 file to 96 and shows the file as playing at 96 on Amarra’s player and is transmitted to the DS Jr via USB. The Tidal MQA version of a file is better than the Tidal non-MQA version of the same file played through Amarra and USB. I am hard pressed to notice any major difference between the Tidal 192 MQA file playing at 96 via Amarra and USB and the same full 192 Tidal file playing via MControl and the Bridge II. Do I simply need to listen more for the difference or recognize less than perfect ears or is any difference a myth? This leads me to the question of whether trying to access my local files on the MacMini through the Bridge II via Roon or JRiver is worth the effort from a strictly sound quality standpoint. Anybody have thoughts here?


I guess the question is, does the second unfold do more than just double the resolution, I can’t answer that as I can only access the first unfold using Tidal’s desktop player. I do think there is very little information or music beyond what you get with 24/96.

We often discuss whether comparisons of MQA files and the 16/44 files are of any value, because we seldom know if the two are from the same source. That the MQAs might just sound better as they were from the original first generation master, while the CD version may have come from a second generation, or a safety copy.

I think you have asked a good question, and I hope someone will do the comparison, and let us know.