Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Streaming DSP5200SE & full MQA decoding

MQA won't allow full sw decoding although I am sure it is possible. Whilst I am sure many things are technically possible it is not what MQA are providing.

For full MQA the endpoint needs to be MQA enabled and if using DSP's they need to be the SE versions, in your scenario where the DSP's do 'some further decoding' what would be the case if you only had analog speakers as is the case for most consumers.

Russ

With the caveat that it's not clear how an 818v3 could render anything above 192kHz, because stated spec of its analog output is 192kHz, as discussed here ?

All I'm going to say is that, in the bottom flow in this image, published by Bob in his Q&A on Computer Audiophile, there is the clear and unambiguous possibility of DSP processing between stages one and two of the decode. Exactly how this is achieved is not, to my knowledge, public domain at this point.

That may be the case for non-MQA material.

What happens in the D2A process when MQA material is being unfolded (pre VK's diagram above) is another matter. I don't believe we know what that is.

Agreed. The same specs for the 818v3 list "MQA decoding and rendering". This could be where the magic is. Still, the analog signal would exit the 818 on the outputs that are limited to 192kHz. Of course, wouldn't be the first time a data sheet was vague or incorrect.

Where does/did it say 192 DACs on the 818v3 analogue outputs? AFAIK, the analogue output card in the 818v3 is a full MQA renderer up to 384k. If it's not, I'm pretty damn disappointed.

The current 818v3 data sheet has no mention of any 192k DACs.

818v3 user guide page 4. See also this thread.

Soundserge

I reckon that's a mistake in the user manual.

I'm right there with you hoping that is the case. Note that the Ultra DAC user guide states:
Which makes me think the 818 guide containing a mistake is less likely.

They would of course need hardware decoding ahead of whatever DACs used. Doing without is only a possibility (maybe) for DSP SE speakers.

I have heard that Roon may soon provide software decoding. Is that impossible, or inherently limited?

Any MQA solution that does not include the final D2A element is by definition limited.

It is my expectation that the Roon software decoding will be "limited" (it sounds pretty good) like the Tidal version, i.e. it will provide a 24/96 stream that is MQA decoded and partially unfolded but does not have the full unfolding (to [up to] 352) and DAC rendering.

Thanks Gianni. This sounds like the 1st stage of decoding that Ronnie described earlier. If Roon can do the 1st stage, is it a possibility that DSP SE speakers could do all of the rest? If so then (for these speakers) hardware decoding would be unnecessary.

It would need Roon to provide an option for users to tell it what lies downstream so that it could add appropriate metadata (or whatever it does) to set things up preemptively for rendering in the speakers.

Just wondering what is potentially possible. The agreement between MQA and Roon may disallow this of course.