MQA usually shows ORFs if the device is receiving a MQA decoded signal called first unfold so I assume you have Roons MQA decoder active? If you don’t have this active then to get MQA output the DAC needs to be both a decoder and renderer.
Changing from Renderer only to Decoder and Renderer will only change outcome if your using Roon to apply any DSP as it would need to be renderer only in this scenario for Roon to apply the first decode apply DSP and maintain the MQA signalling for the DAC afterwards to apply the final rendering stage.
Strictly speaking, any DAC that accepts PCM will accept MQA. It’s still bog-standard PCM. If the DAC knows how to do MQA processing it will notice that there is MQA data encoded in some of the bits of the PCM signal and do something with it.
Yes. In case of mConnect (or playing from a Tidal app directly) you are sending the original bits which Krell decodes and knows that this is the original, unchanged MQA data (that’s the “a” in MQA – authenticated), and indicates so. When you are applying DSP in Roon (that would be the Parametric EQ step in your signal path) that data is changed obviously. Roon has a way of applying MQA’s extra information (or whatever MQA does; not going into that ) and sending it further on to your DAC. DAC sees that it is MQA data that it can further unbfold and render, but it is no longer “authenticated.” OFS/ORFS is the MQA-speak for such data that has been pre-processed externally to the final device in the chain.
Now, which one is higher quality? Whichever one you like best… In the first case, Roon unfolds the signal to 88.1 sampling rate and sends it to the DAC like that. In the second case it’s passed through as 44.1 (which is what Krell displays) and Krell unfolds it further.
Do you hear any difference between the two? If not, I wouldn’t even worry about that. If you do, use the one that sounds better to you.
Learned so much here (thanks all) and been doing a bit more experimenting. So if I turn off the parametric eq this is what shows. Krell in device setup is set to decode only and enable MQA core decoder is off.
Once I turn parametric back on and change settings in Krell device setup I can get either PCM 44.1/24 or OFS 44.1 displaying. Is one better vs another?
You need to ensure you use the correct MQA setting if using Roons DSP. Also do not believe a readout for any MQA as it’s all a black box under the hood any way.
The first decode stage of MQA always takes the source material and unfolds it to twice the encapsulated rate so either 88.2 or 96/24. This can be done via Roons MQA decoder or via the DACs MQA decoder. This is always the case regardless of the original sample rate ORFs or ORS.
The DAC can only handle the rendering stage, this bit is where adding all upsampling occurs and bespoke reconstruction filters unique to your dac are applied. What this actually upsamples to is never shown as it’s a black box.
Some vendors mention it loosely by saying MQA x 4 or MQA x8, MQA x16 this will be 4 or 8 or 16 times the original rate. Some will upsample to the highest PCM rate of the DAC. What they more often show on the display is the ORFs or OFS this is the original sample rate of the material before MQA encoding happened not the rate it’s finally playing at.
If you look at your screen grabs the one that preserves MQA signalling is the correct setting if using DSP as it will maintain the MQA info for the DAC to carry on and perform the rendering stage. If you don’t then you loose all MQA info the DAC will just see the incoming signal as 88.2/24 PCM as Roon has performed the first decode but not preserved MQA signalling. No further processing will occur. If you are not using DSP then you can have the device set to decode and renderer and let it do it all. There is no difference between letting Roon decode or the DAC as long as you set the right setting to preserve the full MQA signal. But only you can decide though if a full MQA processing chain sounds better than half a one do not believe it showing 88.2/24 is better than 44.1/24 MQA or OFS as those are full MQA decode and rendered streams the former is not. But showing MQA of OFS on the display is the same as one another just in one case the DAC is doing it all the other is Roon and the DAC combined.
That’s what I’m asking. What is the correct setup?
That’s a grab without the parametric EQ. I personally love the sound using the EQ so should the settings be in the Krell device setup as decoder and renderer and mqa core decoder is switched on?? If I use these settings, it displays OFS 44.1. Is this giving me the highest possible output preserving MQA using the EQ? Again just trying to preserve MQA and then I can decide which sound I like the most.
It‘s been written before, but I‘ll try to summarize it for you:
Set the core to be the decoder.
Set the Krell to be the renderer.
It makes the core perform MQA‘s first unfold, thus allowing to use Roon‘s DSP functions while preserving MQA information for the Krell to be able do the final rendering steps.
Oh I’m listening! Not agonizing at all just learning and want to take full advantage of my Roon setup. I love it. And have lots of endpoints!
Speaking of and not starting a new thread…I have many Bluesound Nodes and Power Nodes. For getting the most out of its MQA abilities should I also set these to “Renderer only” and the core to decoder?
I also have my Bluesounds running with the Roon parametric EQ.
) and sending it further on to your DAC. DAC sees that it is MQA data that it can further unbfold and render, but it is no longer “authenticated.” OFS/ORFS is the MQA-speak for such data that has been pre-processed externally to the final device in the chain.
