MQA decoding issue

[PeterSt]

iFi's MQA firmware only detects a software DECODED stream as MQA stream WITHOUT further participation of 2nd or 3rd unfolding by iFi hardware. Call it "vapor" ware?

You really make me laugh here !
But let's say it is not easy and one of the harder parts is making clear what the status is, where. In XXHighEnd this is about the Native Sampling Rate (shown in the Hires Audio little logo), the fact that it is MQA to begin with, whether it is decoded or not (just FLAC logo instead of MQA logo) and whether Blue or Green (or even Black, but never mind that). Or nothing because something is wrong. Or how the Native Sampling Rate can just be 44.1 or 48 only (no unfold anywhere).

And let's be honest, in XXHighEnd were problems because
- a PC nog being able to decode;
- I change something so the Tidal connected PC does not need to decode at all, and next the solution for that gets buggy (2.10 vs first 2.10a and next 2.10c - the latter hopefully right).

Also, a major part of this all is that nobody really understands what can happen at the user's side.

Answer: Typicall those albums are encoded as 48kHz MQA file.
Correct.

Meaning Tidal will perform the decoding to a 96kHz audio stream
Also correct. But not with MQA Passthrough ACTivated. But OK, it apparently is their assumption that Tidal will do the decoding :

with the MQA renderer handling the further decoding
Uhm, the Renderer resides in the DAC. Is that not the case with iFi then ?

which this has nothing to do with our products,
Ok, so it does nothing. You are right, it is vaporware.

To test that the actual audio stream in TIDAL is 48KHz please select "MQA passthrough", it is 96k if TIDAL decodes MQA, it is 48k on MQA pass-through.
Although the construction of this sentence is lousy, the bold part without further context is correct. The construction of the sentence is NOT lousy if they don't understand how it works. Apparently they take it that Tidal (desktop) can still decode MQA regardless. Anyway, this should have been written like this :

To check that the actual audio stream in TIDAL is actually 48KHz (it always is, unless 44.1) please select "MQA passthrough"; if it is 96k something clearly is wrong and decoding takes place ahead of our converter and now it can't render (further 2nd and 3rd unfolding)[/i].

...

Answer: Yes, meaning it was MQA encoded from a 192KHz remaster.
Initially nothing seems to be wrong with this. But mind the little bold part. Clumsey expression ? Let's say it is that.

You know what I think happened ? iFi implemented a green and blue/purple light, does not do a thing more but doesn't even understand that.
But could that be true ? it seems too far out ...

Peter

[PeterSt]

From https://ifi-audio.com/portfolio-view/nano-idsd-bl/ :

For mobile DACs with both portability and power considerations, MQA Rendering is the ideal solution as the workload is shared between the host (computer) and the client (DAC). In this case, for a DAC such as the nano iDSD BL, less CPU processing and lower electrical power are needed. This approach for the iFi portable range remains a full end-to-end MQA solution and the listener still enjoys the full benefits of MQA without compromise.

What's this about is that this iFi can act as a Renderer only or as a Decoder plus Renderer (this is elsewhere in the text). The responses you received form tech there are about it acting as a Renderer only, with upside down advices.
But also see what I put in bold in the quote above; there's nothing portable that can decode MQA (yet) so with the example of the Tidal Desktop App (which is a Windows application and which can Decode MQA indeed), there's nothing really much left of the portable part.

British vaporware !
haha

[hudesigns]

To further annoy me is the fact that I also bought iFi USB power supply to work with iDAC2 so it does not draw power from PC's USB bus. The power supply is even capable of separating USB data and power with a USB Y cable. All their rhetoric does not make me feel confident about the company.
ZH

[arvind]

Hi Peter,

I came across a strange problem while playing CSNY\Deja Vu MQA 192 from Tidal.

The first 2 tracks played normal. The third track the speed reduced significantly. I tried playing the tracks again, the first 2 tracks showed input sampling freq of 96, however the third track showed 48, which probably explains the reduced speed. However this time the third track didn't play (even at the lower speed) instead a msg popped up.

I am attaching 2 images for your ref.

Best regards,

Arvind

[PeterSt]

Hi Arvind,

I will check that album, but do notice that it exists that tracks of an MQA album can be non-MQA. I'd say for a normal artist (like CSN&Y) album this is rare but for collections or Playlists this can easily happen for sure.

What I am not sure about at all, is whether XXHighEnd still deals with this properly. So Zheng already reported a "too slow speed", and now you do too, while I never experienced that (and it shouldn't be). Small problem : all my albums have been prepared with the decoder active at the Music Server (Tidal) PC and such a thing can only (?) go wrong with new Preps. Anyway, I will do so with Deja Vu and let you know (later today, if I don't forget).

Kind regards,
Peter

[hudesigns]

Hi Arvind & Peter,
Out of curiosity I downloaded this album and played each track. I found no issues at all--all played with a 96 on input and MQA logo on with blue corner. Now I'm playing entire album unattended, it's still going strong. A delete and re-download might fix the problem for Arvind.

Nice album by the way. I remember I might have an old LP sitting in my wife's collection from college time.

ZH

[arvind]

Hi Peter & Zheng,

Re preparing the stream seems to be the next best thing to do. I’m sure this should sort out the issue in this album.

However it brings up another question, whether a playlist consisting of MQA & non MQA tracks can be played on XXHE?

Best regards,

Arvind

[PeterSt]

However it brings up another question, whether a playlist consisting of MQA & non MQA tracks can be played on XXHE?

Hi Arvind, not really another question because I already talked about that. This definitely should work (was explicitly made fort it), also should still work (while things changed) but testing I am not going to do because I don't know examples. And the minute you do know them, you will have tested it yourself, right ? 

Short answer to your question : Yes.

Regards,
Peter

[hudesigns]

Peter,
This is strictly FYI. I got response from iFi regardiing Tidal-->iFi-DAC MQA decoding issue. Their answers in bold. I think it's a dead end as far as iFi tech support is concerned...  ZH

Hi Zheng,

Thanks for the update.

1. If I let Tidal do the software decode (as seen in video instruction), where does iFi MQA hardware decode come in?

- MQA is in 2 stages, decoder / renderer, so either hardware has both implemented or it has renderer whilst software does decoder.

2. I have both a MQA enabled iFi iDAC2 and a non-MQA Chord Mojo DAC. They both behave exactly the same following your video instruction of Tidal MQA setup - that is with "passthrough" OFF you get 96; with "passthrough" ON you get 48. Where is the advantage of using a MQA enabled DAC like iFi with firmware 5.3 update? Does a MQA DAC suppose to do more hardware unfolding to make some MQA albums to 192 or beyond?

- You need to speak with MQA.

So far all we see is Tidal's built-in software decoding without any participation of iFi DAC hardware decoding.
Please give me some guidance. I am very confused!

- You'll need to see MQA's technology on their website as they are the vendors of this technology.

Hope this has shed some light.

Thanks.
Alix

[hudesigns]

Peter,
I just received response from MQA regarding strange behavior of Tital/iFi combo that we have discussed. It again confirmed that the confusion we feel is legitimate! Here it is:
ZH

Hi Zheng,

Thank you for your support of MQA.

It sounds as if the iFi DAC2 is displaying the incoming digital rates and not the actual rendered, ie full content, rates. In other words, it could be that it is displaying the incoming rate of 24bit/96kHz and then doing the rest of the unfold to 192 but simply NOT displaying this as such.  I would recommend checking in with iFi to see if that is the case.

It also sounds as if you have the Tidal desktop app configured to “Decode MQA”. We would recommend turning this off and then checking to see what the iFi is displaying, including if it shows “MQA”.

How does it sound?

Regards,

The MQA team

[hudesigns]

Peter,
FYI.
I just forwarded the response from MQA to iFi tech team. Here is what I told them:

Hi Alix,
I contacted MQA support team and they responded promptly. I actually understand more of their point of view. For example, I always think why iFi demo wants us to turn Tidal passthrough OFF? In fact it should be set to ON so the iFi DAC can perform magic on the undecoded MQA stream. Once passthrough is set OFF, Tidal will decode, which will result in a PCM stream. If it is a PCM stream already, there is nothing iFi DAC can do about it, that is, no magic. Any MQA DAC needs a MQA stream to finish all the "unfoldings" implied by the original MQA encoded file. Once it turns PCM, the journey is done! This is how I understand it. Here is the response from MQA tech team:

------------------------------------
Hi Zheng,

Thank you for your support of MQA.

It sounds as if the iFi DAC2 is displaying the incoming digital rates and not the actual rendered, ie full content, rates. In other words, it could be that it is displaying the incoming rate of 24bit/96kHz and then doing the rest of the unfold to 192 but simply NOT displaying this as such. I would recommend checking in with iFi to see if that is the case.

It also sounds as if you have the Tidal desktop app configured to “Decode MQA”. We would recommend turning this off and then checking to see what the iFi is displaying, including if it shows “MQA”.

How does it sound?

Regards,

The MQA team
-------------------------------------

[PeterSt]

yeah, well, ...