I have two DACs and the problem on the subject is only happening with the R26. With the SMSL M400 when no DSP is applied the MQA symbol appears in the DAC’s screen with a green dot and when DSP is applied it appears MQA with a green dot.
In the R26 when there is DSP applied the stream received and displayed in the DAC is PCM 48x.
I noticed this a few weeks ago. I am almost sure it was not like this before. I used to get the MQA indication on the display even with DSP enabled.
I have not changed any configuration besides using DSP to improve room modes.
MQA requires an unaltered stream of audio data. If this signal is changed, an MQA DAC will not accept it as MQA anymore. But for Roon, there is an exception. Roon may alter the signal using its DSP engine and still send it to the DAC as an MQA signal. For this, you have to have the option mentioned above as ‘on’.
Also, you have to tell Roon that your DAC accepts MQA in the first place. So a second option must be enabled in your device setup: MQA capabilities; decoder and renderer.
As I mentioned I have another MQA capable DAC and it is working perfectly, showing when the signal is unadulterated, with no DSP, and when it is Mqa with DSP applied. In the case of that DAC, the M400, the core decoder is not “on”, just the same as the Gustard R26.
I have what I think are exactly the same settings for both DACs, and getting different results. Any other settings I should be checking?
Also, I am using R26’s streamer. I am going to try connecting it to my Ropiee through USB. Thoughts?
I’ve placed the Loxjie in the chain as the CXNv2 can’t decode MQA. I’ve had to change Roon’s settings for the Cambridge to get the Loxjie to decode the MQA.
When there is no DSP the Gustard R26 has no issues and receives the MQA signal. When the DSP is on, the MQA signal converts to PCM, and shows on the R26 screen.
Then you need to activate Roons MQA decoder for the device in device settings/advanced it must be active for Roon to process DSP and maintain MQA signalling or it will break MQA if it’s not active and your device needs the correct MQA capabilities set in Roon. In this case set it to be renderer. Roon will then peform the first MQA decode in software. If you have DSP it will preserve the MQA signalling and will be visible in your signal path.
Many DACs won’t show it as MQA as the first decode has been done via Roon and will show ORFs or something similar this just means it’s been decoded before hand and DAC is doing only the MQA rendering process.
Thank you @Simon_Arnold3 !! I am going to try your proposed settings.
There is definitely something being altered because it doesn’t matter what MQA files I am playing, the R26 displays PCM 48khz, which means there should be some downmixing.
After activating MQA core Decoder and setting the R26 as Renderer Only instead of renderer and decoder I am now getting “OFS 192khz” when playing back MQA 192khz. I don’t have a clue what is OFS, but seeing the proper KHz is reassuring.
What is odd is that the SMSL M400 has the core decoder off and it’s set as renderer and decoder and it shows the MQA signal indicator in the screen, with a green dot when it is without DSP and with a red dot when the DSP is on.
Means Original Sample Frequency of master made to make the MQA. As the decode is happening in Roon this is what it will show. If you send a file without DSP to it and set DAC to decoder and renderer it will show as MQA on the DAC as Roon is just passing it through. It really should work setting it to renderer and decoder and activating Roons core decoder, this way if you use DSP it should default to Roons decoder and if not send it through untouched to the DAC to do. Either way its the same as the decode happens in software or in hardware its the same result.
if you dont have roons core decoder active and use DSP then MQA signalling is broken so it wont be working correctly on the SMSL if your using DSP all your getting is undecoded PCM at 44.1/24 or 48/24 and nothing more and the DAC wont see it as MQA. Using any DSP Roon has to perfrom the first decode,
With the SMSL M400 the MQA indicator appears. With the Gustard R26 it works as you say, MQA files appear either as PCM 44 or 48Khz. I haven’t sit to try to identify differences in sound but I don’t like the fact that even MQA 192khz files were being received by the R26 as PCM 48Khz. Some information must had been stripped down.
Now with the setting you suggested most MQA appear as OFS 44/48khz. I have noticed that very high MQA as 192khz do appear as OFS 192khz.
As I said it is loosing MQA signaling if you don’t apply Roons decoding if you use DSP in the chain that is part and parcel of the process. Without DSP it can pass it untouched for the DAC to decode and Render. Please read the instructions and how MQA works.Roon is the only app able to apply DSP to the signal path and maintain MQA signalling but you have to use its decoder to achieve that or it’s stripped out.
The SMSL cannot show anything as being MQA if your applying DSP in the chain and not using Roons core decoder. This is a fact any DSP applied will strip MQA signalling and will stop an MQA decoder and renderer from seeing it as MQA. Show your signal path to the SMSL using DSP with the settings you say don’t have Roons decoder active.
Roon sends PCM to all devices if you apply DSP and don’t use its decoder as MQA signalling will be stripped.
