Question on how DAC’s work...

Hello all!

In my system, my digital sources are a Denon DVD-2900 disc player (CD/DVD-Audio/SACD) & a Bluesound Vault 2. Most of my listening these days is done with the Vault 2 streaming Tidal, especially the growing catalog of MQA offerings. 

My first question is, if I were to start using an external DAC, and that DAC does not have MQA compatibility, would I still be getting the potential of “better sound” from the external DAC even though the Vault is doing all the unfolding?

My second question is if my disc player exports SACD at a different bit-rate than what the DAC is capable of, will the DAC upscale or alter the bit-rate to get better performance?

Sorry if these are rudimentary questions, but the only DAC I’ve purchased to this point is a Meridian Explorer 2 that I’m using in a PC audio setup & was pretty much plug & play. 

Thanks for any help...Hope you’re all doing well!

I'm on the "i don't think MQA is better" camp.

AFAIK, you'll get a 96k/24 bit stream from MQA sources, which is still higher than before.

I'm also in another weird camp: "Modern DACs don't benefit so much from high resolution data."

So, honestly, I'll be surprised if you find a big difference going either way.  My advice to you is to get the DAC which sounds best, regardless of MQA.
Hi @erik_squires 

Understood...thanks for your response. So, in other words, even if the Vault's on-board DAC is still doing the MQA unfolding, the potential for better quality sound from an external DAC exists...even if that external DAC has no MQA capabilities, correct?

Sorry if I seem "dense" on this subject, but DAC specs & compatibility confuse the crap out of me.  Thanks again!

The Vault isn't unfolding MQA if you're passing the digital signal to another dac via digital out, it unfolds if you use the Vaults dac and analog outputs. 
What I mean is, don't buy on MQA.

Buy the dac in your price range which gives you the best sound presentation. Dynamics, bass, extension, smoothness, imaging.  Whatever qualities you want, buy on that.

Don't buy a DAC you feel so-so about because it has MQA.
"The Vault isn't unfolding MQA if you're passing the digital signal to another dac via digital out,"

This statement is not necessarily true. If the "external" DAC is MQA capable, you can select that as an option in BlueOS settings and allow the external DAC handle the unfolding.
The streamer (not the DAC) may partially unfold MQA, which is to 96/24, and send this decompressed signal down stream to a DAC.

Roon, for instance, does this. This is a great feature for me, since that allows me to do some subtle room correction in the digital domain.

You can often also turn streamer based unfolding off, and send the original, MQA encoded signal to the DAC where it will be unfolded if it can be.

In my experience, the sound quality difference between DAC's matters much more to me more than MQA support.

I have one of the early MQA devices and honestly, I didn't care for it. I'm with PS Audio and Benchmark on this whole thing, but to me, this also feels like a solution for a problem we had 20 years ago. Low bandwidth internet, and DACs which played MUCH better at high bit rates.

Now we have much faster internet, and much better DACs that can play Redbook as good as high rez music. So, meh.  I'd rather turn MQA off and pick the digital filter that sounds best.


My second question is if my disc player exports SACD at a different bit-rate than what the DAC is capable of, will the DAC upscale or alter the bit-rate to get better performance?
If you use digital out to an external dac the Denon will only do PCM you're not getting the SACD signal to the external dac so it will play the 16/44 layer. Of course some dacs can upsample/oversample. 
If your preference is to do Tidal MQA and you don't want to use the Bluesound Vault dac you would need a MQA capable dac to do the complete unfold. 
I have 4 pieces of Bluesound kit in the house, a couple of first generation Node N100 players, a first generation Node N150 streaming Amp and a Node 2i.   I’ve used both the N100 and Node 2i pieces with external DACs, in which case both pieces perform the first MQA unfold, getting you all the way to 96K.   This has been the case with both my Bryston BDA1 as well as my Chord Qutest.
I believe the Denon DVD 2900 (I still have one in a closet) takes the DSD from SACD and outputs after converting back to PCM.  My player had no digital outs so you are relying on whatever internal DAC is in the player.
  Sony Universal players are capable of outputting the DSD from SACD over HDMI.  Bryston DAC3 have HDMI inputs.  I use a DAC3 with my Oppo 105 and it also sounds great with my Blusound Vault2 over toslink
@mahler123 do hear a considerable difference in the DAC3 vs the Oppo 105 DAC.
Thanks, @mahler123...I completely forgot to confirm about the digital outputs on the Denon. In my haste, I thought it had a coax among all the other outputs back there!

The denon DVD 2900, at least the US version, has digital coax and optical outputs. Only the 44.1/16 layer of a hybrid SACD will play out. The DSD bitstream of a DVD video will pass to an AV processor on the digital out. 
I have a node 2i feeding into a benchmark DAC2 HGC. I don't notice much a difference on MQA tracks anymore. As others have stated, the node does the first unfold into the DAC. The MQA tracks seemed more impressive when I streamed straight from the node but with the DAC everything just sounds great.
The way I understand things is if you attach an external DAC to a Bluesound Node 2i via digital COAX, you only get 1/10 the unfold of MQA.  Is there a better streamer than a Bluesound that can completely unfold MQA?  If so, which steamers sound significantly better than a Bluesound?  Love to witness a blind testing and then say was that two times better, three times better.

i certainly like my Bluesound Node 2i played by itself than when I added a ProJect S2 DAC.  I think MQA sounds incredible.  Wish I could flip a switch and compare with and without adding an external DAC.  If this Corona Virus gets any worse we won’t be around anyway.
Please see my earlier post in this thread. Via its digital outs, be it Toslink or Coax, Bluesound kit, even first generation Bluesound kit will unfold MQA all the way to 96K when hooked up to a non MQA DAC.
To my knowledge, the current state of the art for streaming hi res via Qobuz or Tidal tops out at 192k, and there is currently precious little material available to stream at 192k, be it via Tidal with MQA or via Qobuz at native resolution without MQA. And from 96K to 192K is just the one last unfold. I’d argue that most of the goodness is already available shy of that last unfold. And I can tell you from experience, that full unfold of MQA via Bluesound kit’s analog outputs, although very nice, is not as good in terms of SQ in my opinion as that provided by a high quality non MQA external DAC hooked up via Toslink or Coax such my own Bryston BDA1 or Chord Qutest.
At that point, it’s really no contest. That has been my own personal experience. YMMV.

I agree with jazzman7....Node2i sounds lot better when connected with a high quality non-MQA external DAC. To my ears, Qobuz native high resolution files beyond 16bit/44.1kHz spec sounds incredible when compare to MQA files. They sound natural and devoid of digital ‘sheen’ present on MQA files.

And those in the camp, “Modern DACs don’t benefit so much from high resolution data” should pursue better Streamer/DAC or get their ears unclogged from excessive wax 😊

IMHO feeding RedBook flac on up to a better DAC  will result in better SQ  than expanding compressed MQA ever.



I just read your reply.  Are you saying if I connected my Bluesound Node 2i to an external DAC using digital coax, I could achieve complete unfold of MQA?  When I attached a ProJect S2 DAC to my Bluesound, the bass sounded thinner.  I think the highs were crisper.  However, when I played the Bluesound by itself, especially listening to MQA, it sounded better and the sound stage really improved.  Unless, more expensive DAC sound a lot better I must not be listening correctly.  Why do I think MQA sounds more lifelike?  It seems like I am the only one who hears the difference with MQA.  Maybe it is smoke and mirrors.  The dealer I purchased my REL subwoofers suggested buying a Belcanto streamer.  He told me it is significantly better sounding than the Bluesound and worth the money.  I never hear anyone in this group mentioning the name Belcanto.

I have lots to learn.  I am not sure how many of you have wives that would divorce you if you purchased a $3000 streamer?
I just read your reply. Are you saying if I connected my Bluesound Node 2i to an external DAC using digital coax, I could achieve complete unfold of MQA 

To get the complete unfold of MQA with an external DAC  the external DAC needs to be MQA compatible, some DAC's will do a partial unfold to 96k. 
if you are using a Bluesound Node of any generation, be it first gen Node N100, 2nd gen Node 2, or 3rd gen Node 2i, as just a renderer connected via its digital output, be it Toslink or Coax, the Bluesound Node acting as renderer will do the first set of unfolds.   If the DAC its hooked up to is a non MQA DAC, that will get you all the way to 96K HZ.  I've had great success with an N100 hooked up to a Bryston BDA1 via Toslink and a Node 2i coupled to a Chord Qutest via both Coax and Toslink.  My results with both setups gave me better SQ to my ears than a full unfold via Node analog outputs.  The digital cables employed can make a difference as well.   Not knocking the Belcanto.  But before putting $1000-$1500 into the Belcanto streamer (I'm guessing the E.One Stream), I'd put that same money into a better DAC.  The Node 2i is a great piece of kit for the money.