Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion MQA - Related technology, products and music "MQA" 818v3 is here!!

But the 818.3 have real 24/192 SL and coax inputs. How could DSP engine still be 24/96?

Digital Inputs:
2x Coaxial SPDIF ≤192kHz/24-bit, DoP
2x Toslink optical ≤96kHz/24-bit
1x SpeakerLink ≤192kHz/24-bit
1x Asynchronous USB ≤192kHz/24-bit, DoP
MQA source decoding

Implementing MQA on the fly for those inputs?

I listened to the 818v3 and DSP7200SE today, all running the latest firmware. Very impressive indeed on a wide range of source material – unfortunately the previous MQA demonstration tracks will not play on the new machine (prototype decryption protocol not compatible with the final version) so we could not hear it in its full glory.

To clear up any confusion on what can be played I took along some ultra high res music (24/352) and some DSD music in DoP form.

Through the USB input
Via the ID41We didn’t test 24/176 or 24/192 files via the ID41 but I am fairly certain these will still be downsampled to 24/88 and 24/96.

The USB input sounded very good but had some difficulty locking to the signal for the first few seconds of the track – it emits a series of clicks for a few seconds before locking, unlike other systems I have heard which simply remain silent until lock is achieved.

I couldn't detect any difference between the final v3 version and the prototype I heard previously - but it was more than six months ago and memory over that period is likely to be unreliable.

Altus,

Many thanks for taking the time to perform these tests and reporting back to the forum, it really helps us to understand what is and what's not possible yet.

I would be great if someone else could perform these tests, so we have a complete base line.

Regards,
Carl

Thanks for doing these tests! Did you buy a set? Or where were you?

It's a big deal that through the USB input an 818v3/SE system can support everything up to 192/DSD without downsampling. Compare to the world of Meridian for over a decade - locked into 96kHz max. I'm very curious to hear this in action!

These restrictions are surely simply because you don't yet have the version of Sooloos which will support all these fully. As John Buchanan said in this post:

We'll just have to wait for this version of Sooloos to appear before we really know what the ID41 is capable of in this context. I don't think it's safe to assume that it won't do everything the USB input will do.

This is nothing to do with the 818v3. Both the ID29 in the 818v2 and 861v8 (and the ID28 which I run parallel in the 861v8 to get more USB inputs) exhibit this behaviour. It is indeed a bit inelegant. But with Meridian now supporting all these new formats, I guess they have to have something which is creaky just as a token gesture.

I have ordered the 818v3 upgrade, but I listened today at Audio Images. Many thanks to Rick and Andrew. Hector was also there and may share his thoughts on what we heard.

I agree it's a big step forward that the USB input is not downsampling 24/192 and I hope you are right about Sooloos ultimately supporting the higher resolutions without downsampling. I was only reporting on the current state of play and also hope that the ID41 "catches up" with the USB in course. The clicking on the USB input is a little clunky - let's hope it is fixed in the next firmware release.

Ultimately I would like to see the 818v3 output a native DSD stream on its (non-MHR) coaxial output to make it more compatible with third party DSD capable DACs. Appreciate this isn't for everyone but for those with a large DSD collection it is important.

Appreciate your efforts Altus, and that you were reporting "state of play".

For me what's much more important as an SACD owner, is that the HD621 (or its replacement) is made to extract DSD bitstream from HDMI and send it to the 818v3 over SPDIF (presumably encrypted by MHR) - IF this is possible, which is not necessarily the case.

Or at the very least allow the HD621 to output 176/192 where the source is that.

Agree that would also be desirable in a Meridian context.

I still like playing my physical SACDs but have also ripped most of them to a NAS, so my drivers are slightly different - I'm looking for a top quality audio endpoint that will produce a DSD output into a DSD capable DAC while still operating within the Sooloos/ Roon family, essentially so that I can play DSD files in exactly the same way I play PCM files.

Thanks for the information Altus... interesting indeed.

Does anyone KNOW what the internal DSP Engine of the 818 is now running at... i.e. the historical 2x rate... or perhaps now at 4x rates??

And yes, I can see that the 818v3 accepts 4x at USB Input... and outputs MHR 4x at its output... which does not necessarily indicate what the DSP Engine is now running at... no matter how much we want to guess.

Also, is there any possibility that the MHR 4x Output is a Folded / Fractal output similar to how an MQA Stream will be "folded" when it's released??

I do wonder why the 1x material is not Upsampled to 4x at Output??... not that I personally think this makes a difference... more of a "tick the box" marketing question.

Hi Altus
May I ask if you have noticed a difference between your DSD files and PCM files that you know are from the same Master??

Or even PCM files converted from the DSD Originals??

Indeed, it may be that the DSPs are simply picking up and displaying a 176 "flag" in the input file while running at 24/88 in the background (but I don't believe this to be the case).

I guess the reason for not upsampling red book 4x is that M have not yet perfected the codec or worked through the compatibility issues with DSPs limited to 24/96. The introduction of MQA will add further complications - judging by what has been written by HQ, it's entirely possible that MQA files will drop completely the sample rate and simply be displayed on DSPs as "MQA" regardless of the underlying sample rate.

I haven't made a systematic comparison of DSD vs PCM files purportedly from the same master - not sure there is much of an overlap in my collection to be honest.

John Buchanan posted about the max data rate of MHR which, as I remember, is less than that required for a rectangular 192/24 stereo channel; so I am certain that the "MQA over MHR" streaming mechanism is being used.

I can't find John's post where he talked of "delivering MQA over MHR" though...

Edit: SpeakerLink sources can query what DSP loudspeakers are at the other end of the cable, so it is possible that if you connected an 818v3 to a pair of non-SE SpeakerLink loudspeakers, regular MHR would be sent. However, it is also possible that the "fractal" stream is backwards-compatible with the old MHR; which would be *so* elegant and *so* Meridian.