File transport vs. audio stream to "Roon certified hardware"

[NOA]

I do have a question and I apologize upfront if this might have been explained in this forum already, I just couldn’t find it.

AFAIK Roon is sending audio stream to connected endpoints. We all know that this is a clocked stream where jitter comes in place an depends on the source how good this is been executed.

If I’m not wrong it is also audio stream send to Meridian or AirPlay endpoints at the moment over the network.

Here comes my question:
Wouldn’t it be better sound wise for upcoming “Roon cerified hardware” letting Roon provide the endpoint getting the file as an unclocked file transport and let the endpoint execute the clocked stream as those usually are optimized for low jitter, usually better than computers running the Roon core?

I’m not a deep tec person, so maybe somebody can enlighten me.

Thanks upfront.

[Carl]

Hi,

If the endpoint is connected via a network, or it’s an asynchronous USB device then audio data (not stream) is packetised and sent in blocks.

For these devices the clocking is performed by the endpoint not the source, which is of course can be very good news re jitter.

Having remote endpoints can also help to decouple the sensitive analogue electronics from the noisy environment of the PC.

Assuming bit perfect data is sent transferred by the server (which Roon can supply of course), then this model effective means that the AQ is down to design and construction endpoint not the streamer.

Regards,
Carl

[andybob (Andrew Cox)]

Hi NOA,
It’s a good question. Brian recently set out some of the thinking as to design choices in this post:

RAAT [was Roon Speakers] - What , When, How and for Whom?

Roon decodes the files itself and then sends a decoded stream to the endpoint, so the Aurender would be essentially a NAS if RoonServer were running externally. An important design goal of ours is that all content that Roon supports can be played on all devices, and that that support works retroactively, even with older devices that haven’t been updated–as soon as we start trusting devices to handle the raw source material (files or protected streams from providers like TIDAL), it becomes impos…

[NOA]

Thanks Guys,

I have read Brian’s post before but I still do not understand it 100% and I would appreciate if you could make me understand the difference between:

File transport
Packed audio stream
Clocked stream
(maybe even anything else?)

What is a streamer like e.g. Aurender or Auralic Aries sending out exactly through their USB and AES/EBU outputs to a DAC from the above when they get the files from a NAS and/or Tidal over LAN?

And if Roon comes in the game using those as an endpoint, is there any change, and if yes which change?

[danny (Danny Dulai)]

I made a few posts on the following thread that cover this, especially the ‘ownership of the clock’ issue.

https://community.roonlabs.com/t/whats-wrong-with-upnp/2101/3?u=danny

[NOA]

Thanks Danny.

No I got it and the question who “owns the clock” makes perfect sense to me. If this will be the endpoints we all can expect the best possible sound with Roon in the game.