Will there be a difference in sound quality between a Roon Ready receiver using RAAT and a Roon Tested receiver using toslink connection?
Toslink might limit you to 24/96 whereas RAAT will not. I always prefer RAAT over every other connection type. Of course, if you want to do multichannel, youâll need HDMI.
EDIT: Probably no difference in SQ at a given resolution. Itâs digital.
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Yes I know itâs limited to 24/96 but is there a difference in SQ if you play a 24/96 file?
There shouldnât be; but itâs implementation-specific.
Which answer would make you happier?
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That there is no difference 
A Roon Ready device is a network streamer that receives the PCM stream and outputs this to various interfaces including USB, Toslink, S/PDIF, or a built-in DAC. In contrast, Roon Tested refers to a DAC. In both instances, RAAT is used to communicate with the device.
So, the answer is no, since both receive the same PCM stream. However, each interface may affect what you hear depending on how well they are implemented. Ultimately, in comes down to preference rather than which, if any, is better than the other.
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In that case, there is no difference. Use whichever is most convenient and gives you the functionality you wantâŚ
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Thanks for clarifying this for međ
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In the end there is always a compromise; only you can decide which compromise you prefer, and that includes how much time and money you are prepared to throw at finding out what you prefer. Iâve stopped at âgood enoughââŚ
If you are brave enough to post what kit you are considering, there will be no shortage of people willing to tell you what they preferâŚ
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Well said and I couldnât agree more. âGood enoughâ is what Iâm aiming for 
Theoretically, no, there should be no difference if the receiver is well-made. In practice, RAAT is an asynchronous packet protocol. Bitstream is produced by the receiver and is clocked to receiver DACâs clock (presumably, accurate enough). S/PDIF, of which Toslink is one version, is clocked at the source, so if the source clock is particularly bad it is possible that, if the DAC does not reclock it anyway, that it will be âworseâ by some measure of âworse.â Will the difference be audible? Unlikely.
RAAT does have other advantages though, depending on implementation, like displaying whatsâ playing on the receiver itself, or being able to control volume from any Roon remoteâŚ
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RAAT is a network protocol between a Roon server and a Roon endpoint, while Tosklink (i.e. optical S/PDIF) is a digital audio interface between two audio components, e.g. a player and a receiver, so we are not comparing apples to apples here. Also, note that whether you use a network streamer or just connect a receiver/DAC to the Roon server, Roon is still using RAAT under the covers.
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Hey Jim, RAAT handles multi-channel as does HDMI. Maybe it depends on the player capability and how far they went with the Roon Ready development. My NUC/ROCK to a exaSound S88 plays 8 channel DSD 256 over Ethernet. Sorry if I misunderstood the reference.
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Once again, weâre not comparing apples to apples. Itâs not RAAT or Toslink/HDMI/etc, itâs RAAT and Toslink/HDMI/etc. If RAAT didnât support multichannel, HDMI would make zero difference.
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I was talking about HDMI vs toslink for multichannel. Can toslink do multichannel? I didnât think so.
But, I donât think I knew Ethernet or WI-FI could do multichannel either.
Technically speaking, it can. Isnât that how we used to send 5.1 Dolby Digital or DTS to surround receivers before HDMI became ubiquitous? But RAAT only sends uncompressed signals, audiophile streamers donât compress them before sending them to DACs and audiophile DACs donât implement it, so for all intents and purposes, youâre right.
As for Ethernet or WiFi, those are not audio protocols, so they can do anything we want them to do, canât they?
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Via Dolby Digital/+ and DTS yes it can and has always supported these. It just canât support lossless as it canât handle the bandwidth. For 99% use cases itâs fine as streaming only compressed surround sound formats.
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Is it? Itâs using UAC2 if you are connecting directly to the Roon Server machine via USB. If I connect a Chromecast Audio to the DAC via Toslink, itâs using some Roon proprietary protocol which may or may not be RAAT â not sure theyâve ever told us.
I think it is⌠RAAT server is what interacts with the OS sound subsystem, which in turn has access to the USB hardware via the kernel and its UAC driverâŚ
Yes. When playing locally, the local server sends audio data to the local endpoint using RAAT over the loopback network interface. That reduces the test matrix by treating the local and remote playback scenarios the same.
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