My Bluesound Node Icon is connected to an iBasso Kunlun headphones amp via XLR. (Which is a killer combo by the way ). So, no external DAC in use.
Just wondering: I’m reading everywhere that QRono d2a cannot be disabled unless you’re routing to an external DAC. However, in my ROON, I’m able to get a purple (lossless) signal path… with these settings in BluOS:
Digital Passthrough: ON
Fixed audio signal: OFF
Which is weird in two ways: 1. “Digital Passthrough” should only be affecting output to an external DAC, and 2. If I can change the volume in ROON (which is a digital thing on the Node Icon), how can the signal path be lossless?
Not that it really matters much to me since QRono d2a sounds fine to my ears (in fact I can’t really hear a difference between lossless and with RRono d2a with my 53yo ears. ), so I’m asking out of curiosity.
mjw
(You want nice, supportive? Call a damn helpline.)
2
This depends on the method of controlling volume. With Device Volume Roon is using signalling to instruct the device to adjust volume. This can be done on the analogue output stage.
Roon displays the Signal Path, which shows exactly what happens up to handoff with the device (the Roon icon) and for some Roon Ready devices, what it signals internally, e.g. if DSP is applied.
The Node Icon doesn’t have analog volume control a.f.a.i.k, it is changed digitally… which means the signal path should be “enhanced” instead of “lossless”, since it can never be bit perfect with adaptable digital volume control.
In fact from what I’ve read it should always be “enhanced”, because it shouldn’t be possible to disable “QRono d2a” on the Node Icon and use “bit perfect” (unless the digital output is used to an external DAC). But here it looks like I can disable it anyway, even without an external DAC?
I’m doing this weird (buggy!) procedure to do three things which shouldn’t be possible: disable QRono d2a, enable the lossless signal path, with adaptive volume enabled:
Go to audio settings (let’s assume we have BluOS standard settings: “digital passthrough” is greyed out, and “fixed audio signal” is disabled),
Enable “fixed audio signal”,
Now “digital passthrough” is no longer greyed out and you can enable it,
Disable “fixed audio signal”,
Now if you close the Audio Settings screen and re-open it, you will find that both of the above settings are greyed out. But now you have the lossless signal path, without QRono d2a, and with adaptive volume slider. To change the settings from here on, you have to reset the audio settings to default.
Nothing here makes a lot of sense to me.
mjw
(You want nice, supportive? Call a damn helpline.)
4
This is incorrect. You are using neither DSP volume nor fixed volume, so Roon is using device controls for volume. This varies from device to device, but Roon will report correctly in the signal path as this is considered as part of the Roon Ready certification.
For example, my Roon Ready DACs with device control use an analogue volume control that Roon can adjust. This includes a Bluesound Pulse Flex, Tanchjim SPACE, and DragonFly 1.2.
That answers the question how ROON controls the volume of the Node Icon. However, internally the Node Icon uses digital adjustment of volume via DSP. So, if you disable “fixed audio signal” in the BluOS app, the signal path can’t be “lossless” anymore. But I guess ROON is never aware of how this is processed internally, it simply triggers ‘volume up / down’ signals. So it shows “lossless” anyway.
Being able to disable QRono d2a still baffles me… but I guess that might be a similar issue of the Node Icon not reporting back to ROON what’s actually going on.
Seems to me ROON and Bluesound need a meeting session together.
). So, no external DAC in use.
