I mostly use Roon so not very familiar with Audirvana, but trying to play hi resolution material on my Devialet Phantoms has had me rediscovering Audirvana since Roon doesn’t support UPnP.
I have Audirvana connected to both Qobuz and Tidal and playing various hi res albums on Tidal got me curious about MQA, so I started fiddling about and trying to understand exactly what the setting do. There are two relevant settings in Audirvana as far as I can see:
“Auto-detect MQA devices” (toggle on/off). While the intention here might be clear, the actual effect is not, and I can’t find any documentation. Could it be that if set to “off” the actual behaviour of Audirvana is determined by setting 2. and if set to “on” Audirvana selects the optimum behaviour based on whatever capabilities the DAC presents?
“DAC not detected as MQA, use as” (not MQA/MQA renderer, MQA decoder). According to my understanding there are only two alternatives here, either Audirvana performs software decoding or it doesn’t (correct?). So why three options? Using the DAC as a decoder means that Audirvana should not perform software decoding, and using it as a renderer means it should, but what about “not MQA”? In this case does Audirvana perform software decoding and send 24/88.2 or 24/96 or not and send the 24/44.1 or 24/48 original file?
To try to answer the above I tested playing the MQA (24/192) version of Norah Jones Come Away with Me from Tidal on both a Dragonfly Red (MQA-capable) and a Meridian Explorer (not MQA-capable). I tried all three settings for “DAC not detected as MQA, use as” with the “Auto-detect MQA devices” switch both on and off (the results in both cases were the same for both DACs so what this switch does is a bit of a mystery. Whatever it does it does not seem to influence whether the decoder in Audirvana is engaged or not).
The results for the Explorer were:
not MQA: Audirvana reports sending 24/96, confirmed by Explorer
MQA renderer: Audirvana sends 24/96, confirmed by Explorer
MQA decoder: Audirvana sends 24/48, confirmed by Explorer
MQA decoder: Audirvana sends 24/48, Dragonfly lights blue indicating 48KHz
So, it seems that my suspicions were correct inasmuch as Audirvana performs core decoding (first unfold) regardless of whether the “use as” switch is set to “no MQA” or “MQA renderer” (but not if it is set to “MQA decoder”). Presumably then “MQA renderer” signals to an MQA renderer to perform the second unfold, whereas “not MQA” doesn’t (and this presumably only in manual mode whereas the decision is taken automatically in “Auto-detect” mode?). Unfortunately since the Dragonfly is limited to 24/96 and the result is the same regardless this is impossible for me to prove.
What I can conclude however is that Audirvana performs the first unfold if the receiving DAC is capable of processing the higher bitrate, regardless of whether it is MQA-capable or not, and that the only way of stopping it is to set “use as” to “MQA decoder”. So the purpose of two switches and three settings is still a bit of a mystery to me.
Thanks @bitracer! Makes sense and tallies with my observations. But leaves the following questions:
What is the difference between No MQA and MQA renderer? Is there any difference in the bitstream that is passed? My understanding is that MQA encoded (i.e. “folded up”) and decoded (i.e. “partially unfolded”) material is transparent to a non-MQA DAC so I don’t understand the need to differentiate between these two.
What does the “Auto-detect MQA devices” do? In my test for instance The results with the Dragonfly were the same regardless of whether this was set to on or off.
Yes, thanks, I saw the same suggestion on the Roon board. Unfortunately it’s Windows-only and I’m a bit allergic. I tried valiantly to get the conceptually similar SonoreUPnP Bridge working, but alas without success. I was unable to get it to see the Phantoms, with or without BubbleUPnP.
There should be a difference in a sense that “Non MQA” outputs plain PCM in 24/88 or 24/96, and the “MQA renderer” outputs a stream that includes coding that is recognised by the renderer and enables further processing.
The Auto-detect is the option that enables automatic detection of the level MQA supported by the DAC, and Audirvana adapts accordingly.
I’m not surprised with your finding that with Dragonfly you don’t notice any tangible difference. It’s quite low end device and it’s difficult to notice such subtle difference.
Or, if you’re in the other camp that does not believe in MQA, you might come to a conclusion that you can’t notice any difference because MQA doesn’t do anything.
Either way, I would actually like to experience MQA on a more high end system. Just out of personal curiosity.
Audirvana 3.5 integrates the MQA Core Decoder that performs the first unfolding (up to 88.2 or 96kHz) to benefit from the high resolution of the MQA audio files even without an MQA audio device. By MQA decision, the second unfolding (to 176.4 or 192kHz) can be performed only in a MQA renderer/decoder DAC.
Non MQA capable audio devices can benefit from the high resolution (doubled sample rate compared to the encoded file one) thanks to the MQA decoder integrated in Audirvana 3.
In this case, Audirvana brings, in addition to the general Sound Quality improvement, the decoding of the MQA file that would be played only at little above CD quality otherwise, losing all its high resolution benefits. Note that decoding the signal beyond twice the sampling rate of the encoded file (for the few rare recordings actually made above 96kHz) can only be done in a DAC MQA.
You then need to leave “Not MQA decoder” for your DAC in the Audio Settings, so that Audirvana performs the MQA decoding.
If you have a DAC that is “MQA decoder” then, you can select MQA decoder. That means that no audio processing done in Audirvana, as the DAC is doing all of the MQA decoding.
If you have a DAC that is “MQA renderer” then, you can select MQA renderer. That means MQA first unfolding done in Audirvana, and no other audio processing as the DAC is doing the other unfolding
The Blue color means that the file is “Studio authenticated”.
The Green color is for other MQA audio file.
Many thanks for the explanations. However, I have read the theory, what I am interested in is the practice. For instance, if Audirvana performs core decoding what exactly is the difference in the payload between the case where it is configured to feed an MQA renderer versus a non-MQA DAC (my tests observed no difference in resolution, but I didn’t do any DPI)? What is the difference in Audirvana behaviour when “Auto-detect MQA devices” is on versus off (in my tests I observed none)? I got some insights from @bitracer, any detail you can add would be most welcome.
You will get better quality if Adurivana is doing the decoding of your music but it also depends of the implementation of MQA on your DAC
The Auto-detection of MQA device is only here to easily set-up Audirvana while you have an MQA device, if it detects an MQA device connected it will switch the audio setting form renderer or decoder and setup the replaygain.