DSD via DoP problems (Raspberry Pi?)

I’m using a Raspberry Pi 3 running DietPi and Roon bridge to play out via USB to my Chord 2Qute DAC.

I’ve been sending DSD as DoP. The Chord DAC lights up white to indicate it’s receiving DSD, and it plays fine. Once every so often when listening to DSD, perhaps once an hour, I get a second or more of audio silence in the middle of a track, and if I happen to glance at the DAC I often see that the white light (DSD) has gone purple (high bitrate PCM) before returning to white when the sound comes back.

I’ve made a change to my setup tonight, and I have set the Roon Core to convert the DSD to 352.8kHz PCM before sending it to the Chord 2Qute. This has worked beautifully, with no glitches so far tonight.

Given that the system can handle 352.8kHz no problem, I assume it can’t be an issue with bandwidth, or hard disk read times. Is it possible that something is going wrong with the Raspberry Pi sending the DSD on via DoP?

You are not the first to have this issue with chord suggest you check elsewhere here to search for chord issues

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Hi @wintoid — Thank you for the report and sharing your observations with us. Both are very appreciated.

I am curious, during your troubleshooting of this behavior have you tried either, A) mounting the the Chord 2Qute to the device hosting your core or B) testing another DAC with the Diet Pi? If so, what was the experience like in either of those scenarios?

Lastly, can you please provide the details of your setup as seen here.

-Eric

Hi @Eric ,

Just to say I don’t need to solve this problem as the workaround is fine by me. If you’d like to continue diagnosing, I’m happy to help. As @wizardofoz has mentioned, this might just be a Chord thing. I know your time is precious.

I’m running Windows Server 2016 off an SSD as a Hyper V host, and the music is stored on a single 5TB SATA hard drive in the server. Roon Core is a Hyper V guest (Windows 10) on that machine’s SSD drive. The Raspberry Pi and my Mac desktop are both connected via gigabit ethernet to the same network switch as the server. My collection is probably 3-4TB of music, mostly flac, but with a reasonably large selection of DSD64 files ripped by me on my PS3.

I’m guessing this is too complicated a setup to be worthwhile testing the Core talking to the 2Qute. What do you think? I’ll do it if you think it’s worthwhile. Otherwise, I could run a USB cable from my Mac desktop (or a Mac laptop on wifi) to the 2Qute if you think that would help for diagnosis purposes?

By the way, I tested changing the buffer size to the maximum, and that made no improvement to the dropouts.

I have 3 DACs, but the only ones which support DoP are made by Chord (2Qute and Mojo). The Mojo is my bedtime/headphone system, so doesn’t get long sessions, and I can’t remember whether I’ve ever had DSD dropouts on it. I could bring it downstairs on the main system if you think that would be useful.

Cheers,

Simon

@wintoid @support
recapping here my tests results from the thread linked above by @wizardofoz :


files on Mac mini’s internal SSD, Mac mini’s USB out:

  • Audirvana > USB Regen > Chord 2Qute -> not the slightest hiccup (DSD 64 and DSD 128)
  • Roon > USB Regen > Chord 2Qute -> not the slightest hiccup (DSD 64 and DSD 128)

files on Qnap HS-251, Mac mini’s USB out:

  • Audirvana > USB Regen > Chord 2Qute -> not the slightest hiccup (DSD 64 and DSD 128)
  • Roon > USB Regen > Chord 2Qute -> not the slightest hiccup (DSD 64 and DSD 128)
  • Aries (Lightning DS, no Roon, no Mac mini) > USB Regen > Chord 2Qute -> not the slightest hiccup (DSD 64 and DSD 128)


after a couple more days testing… I resolved settling on NAS > Mac mini > Aries > USB Regen > 2Qute
but I’m still getting the occasional hiccup (two or three in 4-5 hours of playback)

… definitely looks hiccups are there when files are sent over the network to a Roon endpoint: I had none using my 2Qute via USB either from the Aries (Lightning DS) or the Mac mini (Roon or Audirvana)

oh, and… nothing changed with Roon 1.3-234 (TCP instead of UDP): still having a few hiccups