Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion MQA - Related technology, products and music MQA decoding in Tidal App

Like many of us I’ve been eagerly anticipating the opportunity to hear the MQA process in my system. In order to properly evaluate the MQA process I need to make sure whether I am using the correct settings/workflow and seek clarification on exactly what signal is being sent to my DAC.

My understanding is that the desktop Tidal app performs MQA decoding in its software and pushes the decoded digital signal out to ones’ sound card or external DAC.

In my case I run the Tidal app on my home office iMac and its output is sent to an Explorer 1 (Non-MQA capable). So if my logic is correct, on my desktop system the Tidal app is performing the MQA decoding and sending the decoded digital signal to my Explorer for conversion to an analog signal output.

Where things get fuzzy for me is how this process is performed in my main hi fi system. (Networked MC200 / external DAC.)

Here is my workflow: I am opening the Tidal app and selecting a few albums in the “Master”section and selecting them as my favorites and they are added to the “my music” folder. Then I open control MAC and navigate to the Tidal section wherein I scroll through “my albums” and select a particular MQA encoded recording and “add it to my library”.

All this is well and good and I am able to stream the Tidal MQA encoded albums through my MC200 / external DAC into my main system.

What I am unclear on is whether (and where) the signal being fed into my MC200 via this method is being “decoded”. My thinking is that I am just hearing the MQA encoded (but not decoded) album via this method.

Put differently, is the MQA decoding being performed in the Tidal cloud? If I were to turn off my iMac or quit the Tidal app, where would the MQA decoding take place?

I’m not trying to be ungrateful for the added sonic benefit Tidal offers via MQA Masters, but I also don’t want to erroneously infer that I am getting a “decoded” signal via this method.

Any clarification is appreciated.

Mainly a matter of nomenclature. Most anything can play a MQA file as it is backwards compatible. However, only an MQA enabled endpoint or DAC can decode the file completely. So, this said, an Ultra DAC, 808v6, 818v3, 218 or other enabled DAC can fully decode the MQA their analog outputs. The 818v3, 808v6, and 218 can decode the MQA file and send it via their speakerlink outputs to SE speakers. Even without full MQA decoding, the folks who are simply able to play the file with their current hardware still get an extremely good quality recording and comparatively smaller file size. I hope this clarifies things somewhat.

Matsaly - Just to follow on from Bruce's comments ... looking at your equipment list, you're not getting any unpacked MQA goodness when you play Tidal tracks through your main system.

Your MC200 is not decoding the MQA file at all - the firmware changes to enable this haven't arrived yet. Like Bruce says, it's simply passing the backwards-compatible MQA file through its DAC, which treats it just like a conventional FLAC audio file.

Apparently a non-decoded MQA file still sounds a bit better than conventional 44.1/16 audio, so any improvements you're hearing in your main system are due to this. So like Bruce says, to get the full MQA experience - pending the release of new MQA decoding firmware for your MC200 - you'll need an Ultra DAC, 808v6, 818v3, or 218 to do the decoding.

HTH! :-)

So the implication is (and apologies if I have this totally wrong) that a PC running Tidal in decode MQA mode is outputting a decoded MQA 24/96 stream which can be accessed via a USB to SPDIF converter?

I thought that MQA over SPDIF was a no-no? Remember the fuss about the Aurilac streamer.

I am guessing that if my deduction above is correct then the MQA digital feed will not have been corrected for the target DAC as there is no feedback route from the DAC via USB into the Tidal app? Meanwhile an MQA-enabled DAC will do that final bit of MQAing, i.e. unfold the 24/96 into 24/192, correct for itself (as it were) and perform the D2A?

As far as I understand it, MQA decoding in software uses a "generic" DAC profile in the absence of knowing anything about the target DAC. Assuming, therefore, that the USB-SPDIF converter appears as a listed audio output device in the Tidal streaming settings (and there's no reason why it shouldn't), then software-decoded MQA should be passed to it, using the generic DAC profile. So yeah, pretty much what you said!

One of the really interesting questions will be the degree to which MQA-certified DACs can actually do a better job of unfolding MQA than their software equivalents. How much better SQ does specialised hardware provide than generic software ... lots, or only a bit?

Actually, I'm about to conduct that experiment myself. The current office system is MBPro/Tidal MQA decoding -> Explorer 1 -> Stax SRM-007t/SR-007s ... so unfolding is being done by software on the laptop. However, an Explorer 2 is winging its way in my direction at the moment - the system will then be MBPro/Tidal -> Explorer 2/MQA decoding -> Stax SRM-007t/SR-007s. When the new hardware arrives and is plugged in, I will report back! :-)

You got it

I'd be really interested in hearing these perceptions Kent, as mulling over an explorer 2 as we speak vs waiting on Roon.

Lee

In that case it begs the very expensive question as to why Sooloos could not incorporate a similar basic MQA decoder to deliver from a multi-£k investment (in my case and many others round here) what can be got as a free feature in a £20/month streaming subscription.

Especially as I believe VK suggested that Roon would include such a feature in the future.

This came up in another thread ... the issue may be the relatively high processor requirements for unfolding MQA, if the stats from the Tidal client on my Mac are anything to go by. Much of the existing Sooloos kit may well simply lack the horsepower to unfold MQA.

Both Tidal and Roon have the advantage that they are typically working on laptop or desktop class processors, rather than the low-power chips and specialised DSP hardware in current Sooloos boxes.

I guess we will have to wait and see if MQA on (say) an MC200 is technically feasible.

Kent in Welly - thanks that helped me understand the technical issues and limitations.

So for partial MQA goodness I should take up a Tidal subscription and stream using the Tidal desk-top app via the USB port on my 818v2; upgrading to an 818v3 gives me no MQA-related advantage whatsoever over that solution since none of my speakers (DSP33, DSP7200.1, DSP8000.1) are MQA capable (yet).

That titchy sub-£200 Explorer 2 must be very well endowed internally since, lacking any digital output, it must be doing the whole full-fat MQA decode.

I guess it's the difference between specialised DSP chips that are intended for that one purpose, versus general purpose processors. I wouldn't think that there are any big issues with unfolding MQA on a DSP chip, so DACs and the like could be nice and small ... like an Explorer, for instance! :-)

I think the problem will arise with more generic hardware - and that's where earlier versions of the MC200 could struggle. Basically they're just a low-cost fanless PC with a decently-specced sound card, and some of them are more than 5 years old now (which is an eternity in IT years). So I can easily foresee some of those not being up to the task.

That's the bit I can't figure out yet. If there's no difference between the software unfolding on a generic DAC profile and the dedicated hardware unfold on an 818v3, then there's no point in doing your upgrade (aside from the convenience of being able to stream MQA remotely, a la Roon, versus having to have a laptop attached to your 818). If, however, hardware unfolding and a proper DAC profile makes a big difference to SQ even into your current system, then the upgrade is probably money well spent. It's hard to tell at the moment!

Anyone did this experiment on an 818v3?