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

Thanks VK for the interesting post and congratulations on your 818v3.

I assume you connected the output of the 818v3 via digital coaxial to the 861v4?

Presumably the 861v4 down-sampled any bit-rate over 96k?

What did the displays on the 861v4 and DSP6000s report?

Yes, connected via coax; the 861v4 reports 88 or 96. AFAIK, it won't accept anything more, so I'm pretty sure that the 818v3 only outputs up to 2x sample rate over MHR over coax. OTOH, I'm pretty sure that over SpeakerLink with a confirmed v2 comms link the 818v3 will output higher rates using compression (over MHR). I also suspect that only the newer (current?) DSP loudspeakers can decompress these streams.

Edit: 6ks are not dot matrix, so I only get an indication of high rate (dot) or not.

Thanks.

It would be interesting to compare the 818v3 analogue output into the 861v4 with the digital output.

The 861v4 is already getting very accurate 88/24 from the 818v3; and by very accurate, I mean that I am quite certain that the MQA sampling process uses a kernel which spans samples. i.e. the value of the waveform measured by the ADC is integrated over (say) two samples using a specific "shape". The MQA decoding process does the inverse, thus arriving at PCM which is far more accurate than Nyqvist sampling theory would suggest (for a given sampling frequency).

By contrast, the 861v4 ADCs (e.g. IA45 card) use a conventional Nyqvist "point in time" sampling paradigm and, by definition (and with some irony), the "signature" of the ADC is encoded into the digital; and there is no way to correct for this.

In other words, the 88/24 PCM (over MHR) from the 818v3 is going to be far more accurate than 861v4 re-sampled analogue from the 818v3. It's not an experiment that I'm interested in.

I think why this question is up because a report of 818v3 connected to 861v8 via coax does not sound as good on MQA as via analog connection.

But the 861v8 does have an improved AD card more so than 861v4 so I would not automatically assume that would be the case here on 861v4.

I don't know who made that report (can you link to it?) but I find it very hard to believe. It may sound "different", but "better" is another thing entirely...

On the iPhone, but post:
#246844 - February 10, 2016 Re: MQA listening impressions (with a MQA decoder)

The HS=Y/N comment regarding analog input is also interesting. He might be on to something. This was 818v3 connected to 861v8 via both MHR and Analog listening to MQA.

What we should all be doing, of course, is requesting that Meridian provides MRC for the 8x8.

+1. Already done.

And MQA support on the 861...

Sure, but we are pretty sure that that *is* on the roadmap. MRC on the 818 has not, to my knowledge, really been discussed.

Well, if that is the case, then MQA is firmly off my roadmap.

I have no intention at this stage of buying an expensive audio endpoint for a format which IMHO has a high probability of disappearing into obscurity.