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MQA & External DAC

garrsmith

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Good Afternoon. I am a newbie and beg for your forgiveness if I misstate anything.

i am using tidal and want to take the full advantage of the MQA option with my subscription. I am starting with a Bluesound Node 2i and based of reviews and forums have learned the internal DAC isn’t all that. I have been researching external DACs many reviewed here. However based on the choices I was gravitating to the MQA unfolding is occurring across usb not analog based ports. I need to go analog with my old school Denon AVR-2000. When we are finished building the new house I will install my Anthem MRX-720 and use that to drive the speakers. Is there a DAC that does MQA across the analog rca ports on the BS Node 2i to the chosen DAC That meets the standards of audiophiles such as yourselves?

Thanks,

G
 

Jimbob54

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Good Afternoon. I am a newbie and beg for your forgiveness if I misstate anything.

i am using tidal and want to take the full advantage of the MQA option with my subscription. I am starting with a Bluesound Node 2i and based of reviews and forums have learned the internal DAC isn’t all that. I have been researching external DACs many reviewed here. However based on the choices I was gravitating to the MQA unfolding is occurring across usb not analog based ports. I need to go analog with my old school Denon AVR-2000. When we are finished building the new house I will install my Anthem MRX-720 and use that to drive the speakers. Is there a DAC that does MQA across the analog rca ports on the BS Node 2i to the chosen DAC That meets the standards of audiophiles such as yourselves?

Thanks,

G

You are asking the impossible. The analog outputs on the node are just that- as in not digital. MQA is a digital format and a decoder has to convert the MQA file into analog to pass to an amplifier and onwards. Once it has been decoded (as will any other digital file) and converted to analog by the Node DAC it is no longer an MQA file- or any other type of file, it is analog electrical.

You can pass the digital signal out of the Node 2i coaxial/ optical digital output (cant remember which it has) to a separate DAC but I dont believe it will pass the undecoded MQA file on undecoded- but that is dealt with in other threads here- search Node 2i MQA DAC or similar.
 
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garrsmith

garrsmith

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I apologize clarify further I meant the Node 2i connected to my Denon via RCA. Then the Node 2i via toslink/coax to the DAC. Still learning.
 

Jimbob54

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I apologize clarify further I meant the Node 2i connected to my Denon via RCA. Then the Node 2i via toslink/coax to the DAC. Still learning.

I seem to recall the Node does the first unfold to 96khz then outputs that via the digital to the other DAC. Which might well be better than the DAC in the Node via analog outs but not what you are after.
 

Webninja

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I had the Node2i on my shopping list, and this site helped me understand how it unfolds MQA content.

https://support1.bluesound.com/hc/en-us/community/posts/360037876633-MQA-Confusion


When streaming MQA through the Node 2i, the BluOS app will handle the first decoding stage which will process the MQA file to 24-bit/96KHz audio. The next 2 rendering steps are then handled by the internal DAC of the Node 2i which will then allow 24-bit/192KHz audio.

When using coaxial or optical cable from your Node 2i, you are bypassing the internal DAC of the player which is resulting in only the decoding stage occurring and only outputting 24-bit/96KHz audio. To get full 24-bit/192KHz audio you will need to use the analog RCA outputs of the Node 2i to have the internal DAC of the Node 2i process these 2 rendering stages and output fully unfolded MQA.
 

scrubb

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Every MQA compatible DAC I've seen can only do a complete unfold through the USB input, which as far as I know, means you have to feed it from your computer. I have a Node 2i and recently purchased a SMSL M500 (MQA compatible) DAC which I feed via coax from the Node 2i. MQA files are read as 96KHz "Hi Res Audio" by the SMSL. In my untested opinion, they still sound better than the full unfold through the Node's internal DAC and analog output.
 

watchnerd

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Every MQA compatible DAC I've seen can only do a complete unfold through the USB input, which as far as I know, means you have to feed it from your computer. I have a Node 2i and recently purchased a SMSL M500 (MQA compatible) DAC which I feed via coax from the Node 2i. MQA files are read as 96KHz "Hi Res Audio" by the SMSL. In my untested opinion, they still sound better than the full unfold through the Node's internal DAC and analog output.

Well, there are the streaming amp/DACs like the NAD M10 that can do it via network input.
 
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garrsmith

garrsmith

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Every MQA compatible DAC I've seen can only do a complete unfold through the USB input, which as far as I know, means you have to feed it from your computer. I have a Node 2i and recently purchased a SMSL M500 (MQA compatible) DAC which I feed via coax from the Node 2i. MQA files are read as 96KHz "Hi Res Audio" by the SMSL. In my untested opinion, they still sound better than the full unfold through the Node's internal DAC and analog output.


it’s funny you should mention that make and model. I was just reading up on it.
 
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garrsmith

garrsmith

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I had the Node2i on my shopping list, and this site helped me understand how it unfolds MQA content.

https://support1.bluesound.com/hc/en-us/community/posts/360037876633-MQA-Confusion


When streaming MQA through the Node 2i, the BluOS app will handle the first decoding stage which will process the MQA file to 24-bit/96KHz audio. The next 2 rendering steps are then handled by the internal DAC of the Node 2i which will then allow 24-bit/192KHz audio.

When using coaxial or optical cable from your Node 2i, you are bypassing the internal DAC of the player which is resulting in only the decoding stage occurring and only outputting 24-bit/96KHz audio. To get full 24-bit/192KHz audio you will need to use the analog RCA outputs of the Node 2i to have the internal DAC of the Node 2i process these 2 rendering stages and output fully unfolded MQA.

sorry @Webninja didn’t realize these were the same article.
 
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garrsmith

garrsmith

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I looked at the NAD options the C658, and M10. They seem to have software bugs frequently. I have heard nothing but good things about the Naim Atom. At $3300 I thought I would grow into that. Mostly positive about the Cambridge Audio CXN V2. This has the two Wolfson DACs. I figured at the price point though do a Node 2i and choose my DAC. However, didn’t realize how hard a pursuit that was. most of the MQA DACs only unfolding MQA across usb. the Mytek Brooklyn, is nice, but with that and a node your inching close to the Naim.

I have read s much my head is swirling with all the info.
 

watchnerd

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As far as I know, the Naim's don't have room correction.

If that matters to you.

(it does to me, as my current Devialet does everything else the Naim does except MQA)
 
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garrsmith

garrsmith

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Every MQA compatible DAC I've seen can only do a complete unfold through the USB input, which as far as I know, means you have to feed it from your computer. I have a Node 2i and recently purchased a SMSL M500 (MQA compatible) DAC which I feed via coax from the Node 2i. MQA files are read as 96KHz "Hi Res Audio" by the SMSL. In my untested opinion, they still sound better than the full unfold through the Node's internal DAC and analog output.

I am still looking at the m400 versus the m500. seems to be an ES9038Pro Dac versus an AK4499EQ. Since I havent heard either, thoughts?
 

Jimbob54

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I found this thread. Interesting read.

ES9038pro vs AK4499eq

I think Martin's thoughts here

https://www.audiosciencereview.com/...-dac-x26-vs-gustard-dac-a22.11424/post-421289

would echo the view of many on here. Pick the device you want based on features, appearance, build etc. More importantly, price! Or buy both and do proper level matched ABX testing and return either the one you prefer or is more expensive depending on whether you prefer one or cant tell the difference. Most here would say it would be the latter under proper conditions.
 

charleski

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If you want to understand MQA the best resources are to be found in Archimago’s old blog posts. A good starting point might be this comparison. Just type ‘MQA’ into the search box on his blog and you’ll find a load of articles on it.

Unfortunately MQA marketing obfuscates the whole process (perhaps deliberately). The ‘first unfolding’ process appears to consist of taking information stored in the bottom 3 bits of the 24/48(44.1) file served up by Tidal and using that data to reconstruct a lossy approximation of the ultrasonic content at 96 or 88.2kHz. This is done in software. The second ‘unfolding’ happens in the DAC and is performed by using an extremely short digital filter that deliberately allows through a lot of ultrasonic noise that is an integral part of the sampling process and usually suppressed by DACs that use a sharp filter (as it’s basically garbage). It also produces aliased elements of the low-frequency signal that are visible as faint vertical lines in Archimago’s plots. This allows them to generate a signal at 192 or 384kHz.

As Archimago’s comparison shows, the critical part of the process is the ‘first unfolding’ that happens in software and seems to produce a reasonable approximation of low-level high-frequency content up to 48kHz. I wouldn’t get too worried about the second hardware-based ‘unfolding’ as it’s basically just a big fudge.

As a technical note, I’ve often wondered whether MQA is based on an attempt to implement some of the work done by Martin Vetterli and Thierry Blu in which they showed that the band-limiting that’s an essential part of the Shannon-Nyquist theorem can be converted into restricting the signal to a finite rate of innovation. If you read Bob Stuart’s interview in Stereophile he seems to be pointing to this in several places, though he fails to provide any credit.
For some articles on this theory see
Sampling Signals with a Finite Rate of Innovation
Sampling Moments and Reconstructing Signals of Finite Rate of Innovation
Be warned that these are very technical articles, and I don’t pretend to understand them on more than the most basic kindergarten level, but there are definite similarities to the (very limited) technical explanation Stuart uses in his interview.
 
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Zensō

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Hi - I am also looking at the Node with external DAC with MQA. According to this article at bluesound you can bypass all MQA processing on the node and let your DAC do it alll. My take away is this means you get the full MQA experience. Is my assumption correct?

https://support1.bluesound.com/hc/en-us/articles/115006191908-Why-Isn-t-My-External-DAC-Playing-MQA-

If you’re going to bypass both the MQA decoder and the DAC in the Node, you might consider a Raspberry Pi streamer instead and save yourself a few hundred dollars.
 
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