Howdy; I was curious about the RAAT process and how to ensure that the DAC is receiving the highest quality connection from Roon Core; I have been running a ROCK (i7 Nucleus+ spec) for years and it’s excellent- no issues, but the other day while streaming Netflix from Roku device, I noticed (usually) poor video resolution at times; presumably the network is buffering, FIFO’s are running low in the ROKU from dip in WAN bandwidth, or WiFi degradation. So I was wondering, can the resultant audio performance from a network rendering equipped DAC, degrade if the WAN download rate drops sporadically? I have noticed on occasion, that the streaming DAC sound degrades over time, and I have gotten into the habit of rebooting ROCK and the DAC and the performance is as it should be.
I am not sure if this is proportional with download link rate or some other network/ rendering timing gremlins. I doubt that it depends on WAN performance, as I thought RAAT is designed to guarantee a consistent quality of service, but I’m definitely a bit fuzzy on the details. I was hoping for some clarity here from the network pros, or tips on how to configure ROCK properly. Thanks!
No. RAAT does not use dynamic variable rate audio streaming. That is largely the realm of lossy video codec streaming. RAAT is lossless. Either it works at the set rate or it stops and stutters.
AJ
Can you describe what this degradation sounds like? What DAC is this happening with?
As you say, RAAT should provide a consistent quality of service. It’s quite different from the protocols Netflix uses, as Andrew notes above.
The terminology that I really should have used is “adaptive rate.” Lossy video codec streaming typically adapts its resolution or bit rate or both to network conditions. Under the hood, Netflix has multiple 4K bit rate tiers. Resolution may remain the same, while compression quality may vary.
RAAT does not do anything like the above.
AJ
Thank you for the explanation.
As for DACs; I currently run a Bricasti M21, but have had Bricasti M3 and M1, and a Meitner MA3 prior, as far as ethernet DACs; Additionally I use a Lumin U2 mini with various USB Dacs. I have noticed over the years, regardless of DAC or method of streaming the data to them (ethernet or USB) that eventually I notice, what I call “treble fungus” start to creep in. Soundstage shrinks, highs are less clear, a slight gray hue is present. It sounds like the music has lost its mojo, and has lost its color. When I start to notice this, I begin resetting the router, switch, dac, roon core; This usually restores the musical force. I am always left wondering why this happens in the first place. I have read on Audiogon that many others experience a similar thing, so whatever the mechanism is, it seems not to be geographically isolated, but due to some overarching thing. Maybe it’s the source servers, like Qobuz or Tidal and the practice of resetting the network appliances resets my brain/expectation. At times the treble fungus is bad enough that I spin CD’s and voila, music is real once more. I would love to understand everything at play here.
I can’t think of anything on the digital side of the world that would cause this. Bits don’t change. Even with DSP, it would be hard to achieve, I think. Sounds like an analog effect.
Yeah, an “analog effect” of the brain. A product of either or both individual psychology and collective groupthink.
AJ
The common factor seems to be auditory fatigue setting in due to too much intensive critical listening…
Could be. Left / Right Brain Dichotomy Fungus…I’ll go with that 
My “solution” is to switch between location and systems just often enough that the system(s) where I arrive sound delightfully fresh, and the ones I came from get forgotten so that they can sound delightful again when I return to them 
The problem is in fact in the analog section. The longer you play music, the more the wires to your speakers heat up. Hotter wires have more resistance, which affects the frequency response. Hence treble fungus.
You can find out more about this on The Onion.
Before i get the aggressive comments, please note The Oniion reference.
Although it’s eerily plausible.
Agitated electrons mess up your treble 
“I am always left wondering why this happens in the first place. I have read on Audiogon that many others experience a similar thing, so whatever the mechanism is, it seems not to be geographically isolated, but due to some overarching thing.”
Yeah, this a psychoacoustic thing. I bet it clears up if you get outside and get some exercise, do some good for others, or enjoy a cool beverage. Come into your listening sessions feeling good about yourself and I bet this goes away. Or you could set up some PEQ profiles in Roon and swap in a different profile if you want to change the balance on any given session. Chasing ghosts like cables, streamer set ups, DAC differences isn’t going to help.
ah, could be. I’ve noticed that after an intense MTB ride or run, system is sounding excellent. What is strange though, when I notice the dreaded TF, is that I can switch in a CD from my transport and I swear it sounds better. Is this just expectation bias? I’ve also wondered about static build up…sometimes I’ve unplugged everything, let it all drain for an hour or so, then come back to it and voila…right as rain. Funny, I never experience this malarky in my car or via my headphones…
Well, not necessarily, but it could be psychological. Streaming may be associated with higher stress levels – where is it coming from? Is it going to keep going? – that might be alleviated by knowing the source of the audio data and having control over it. Even if this is all subconscious, it could result in the CD sounding better.