hissing after a while (10 minutes)
stop/resume fixes it then… again
Macmini quad core i7 2.3GHz, Mac OS 10.11.6, DLink DGS-105 switch, Auralic Aries “femto”, Chord 2Qute
Gave up longtime ago on DSDs (64: nothing I care about available at higher resolutions) because of hiccups
Two or three old threads with all the details and what I tried to no avail are already there
:-/
If you have the file local on the Mac Mini and the 2Qute is plugged directly into the mac mini, do you still have issues?
If you have a NAS mounted via SMB, macOS often has these kinds of issues unless you tweak some OS-level settings. If that’s your setup, I can dig out my thread with the info on how to fix it. If the music is all local (not networked), then please ignore.
-mike
yes, Mike: files are on a Qnap hs-251+ mounted via smb
though I’m having these issues only when Roon is involved: using the Aries on its own to the 2Qute or Audirvana to a Metrum Hex all plays just fine :-/ (can’t try DSD with the Metrum, just up to 24-192)
not sure A+ can use the Aries as network renderer: let me see and, in case, try that too
Daniel… this is quoted from my old “Hiccups with DSD” thread:
“files on Mac mini’s internal SSD, Mac mini’s USB out:
files on Qnap HS-251, Mac mini’s USB out:
looks, though, I should run each setup for days if not weeks to reach an actually true conclusion :-/
Try the steps here:
https://discussions.apple.com/message/30260816#30260816
They disable some extra security on SMB that you likely don’t need if the NAS is within your home firewall and for some reason seems to give the Mac trouble. This helped a lot with my NAS.
thank you Mike: will give that a try
though, as per my previous testing sessions, issue looks to depend on Roon + network renderer + Chord DACs
at the end of my old “Hiccups with DSD” thread, in fact, latest posts from Roon staff reported they were working on this with Chord. No further update since 
btw… forgot to say (once more) that both Mac Mini and Qnap NAS are dedicated machines: Mac is running just the OS and Roon Server, NAS only holds music files and is only accessed by the Mac mini. Plus it has every service but SMB turned OFF
also… Roon reads at a constant rate (1-2MB/s max, if I recall) whilst Audirvana preloads every track reading at up the max the NAS can reach (50+MB/s) and… no issue at all in Audirvana
Our investigation is meant to attempt to reproduce and document the issue properly so that hopefully Chord can do something about it. There is a small chance that we will find out this is our fault–in that case we would fix it. But I’m pretty sure that this is not the case based on the symptom description.
A DAC should never play a hissing sound unless someone is actually sending data that contains that sound. It’s pretty difficult to imagine how Roon could do that–we don’t have code that generates noise patterns, and the kinds of bugs that our code could be subject to would not produce an effect that matches your description.
It seems more likely that the DAC is in sensitive to something–a timing detail, an ordering detail, a buffer size choice, something like that. And something totally benign/legal that is happing during playback from Roon is interacting badly with that sensitivity and triggering a bug on the DAC side.
This is consistent with all of the reports we have heard about this symptom, but I can’t say with 100% certainty until we’ve reproduced the issue in-house–and that has not been possible yet–we are still waiting for some Chord hardware to show up so that we can test everything at once and get a handle on the scope of this.
thank you for the update, Brian 
I’m not holding my breath on Chord’s “software skills” (after playing a while with a Poly before sending it back 
). it’s a real shame as their DACs are great indeed