MQA first unfold in Roon? MQA? [Delivered in 1.5]

Yes of course.

Correct.

Incorrect. Damien confirmed that, when an non-MQA DAC is specified, first-unfold is followed by upsampling (if enabled) followed by AudioUnits (if enabled) followed by Volume Control (if enabled).

If this the case, up-sampling and volume will disrupt the information and it will not work when renderer devices such as Dragonfly and Berkeley DACs are used.

Reread miguelito’s quote: “non-MQA DAC.” Downstream rendering is irrelevant.

AJ

I would be utterly flabagasted if that were not the case.

Exactly. And we can use precedence (Audirvana) to get an idea of what to expect, as a minimum…

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MQA full decoding is two steps:
1- Core decoding (aka first unfold) that gets you to 88 or 96 KHz
2- Upsampling with MQA-specified filters
What I am saying is A+ can do step 1 and then upsample / do volume control. You’re correct that a renderer after step 1 will not be able to do step 2 if I apply DSP or volume control. I am saying I am willing to give up step 2 in favor of DSP.

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This will surely be an option.

You must be a lawyer… :slight_smile:

Ha no but when you’ve worked with many of them, you start to mimic their writing styles sometimes - unfortunately LOL.

I am using dCS.

My understanding of the dCS implementation:

The network card does the first unfold and the FPGA DAC does the rendering. The first unfold can only happen if you’re using a Rossini, Vivaldi One, Network Bridge, or Vivaldi Upsampler and only over the network interface. Only Rossini is able to do this right now, firmware updates will come out for the rest.

If you’re connecting to a Rossini or Vivaldi DAC directly over USB, even after the MQA update, you will need to do the first unfold in the TIDAL app, Audirvana or Roon (when it supports it). Volume control should still be available as the volume control in this case messages the DAC rather than changing the bitstream.

My understanding of the dCS implementation:

I am using the Rossini Player. It is connected to the network via wired ethernet. I have no use for USB. Passthru MQA is checked in the Tidal Ap. All processing is performed in the DAC section of the Rossini. Once dCS has completed updates for the Vivaldi/Network bridge I will audition and consider those units in the future.

I am in exactly the same situation: Rossini+Clock connected over wired ethernet. I will consider the Vivaldi on my next upgrade.

Correcting myself: There’s only one “second unfold” and it is upsampling with MQA-specified filters. That is it.

Isn’t that also when this “deblurring” happens too?

All that happens in the second step is upsampling with specific MQA-specified filters. There’s no other processing.

You could call these min phase filters “deblurring” in the same way I could call the shorts I am wearing right now “contour fitting sexy trunks”. Just words.

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I have heard that this is a feature of MQA2 and will of course require you to buy another MQA2 DAC (your existing MQA DAC will not be capable). You will also need to rebuy all the music in MQA2 format due to a fresh round of re-remastering… :slight_smile:

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I found an usefull and not too technical explanation about MQA and the different unfolding stages here:

https://www.kefdirect.com/mqa-basics