Mac Mini (Late 2014) OS X 10.10.5/ Roon build 521
Music files are stored on a QNAP TS-431 NAS
Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)
FIOS-G1100 router, Trendnet TEG-S80g gigabit switch, two TP-Link MC200CM Gigabit Media Convertors between the Trendnet switch, and the Allo USbridge. I am using Ethernet.
Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)
Pro-Ject Pre Box S2 Digital DAC connected to an Allo USBridge by USB and then out to a Marantz SR5010 AVR CD input.
Description Of Issue
When Roon switches from a Flac 44/16 track to a DSD64 track, I hear static for about 7 seconds over the DSD track. After the static fades, the track plays normally. This only occurs when listening through the Pro-Ject DAC. It does not occur when listening through the Mac Mini HDMI output to the Marantz AVR. It also only occurs when switching from 44/16 to DSD. No other bit rate or sampling frequency produces this issue. It occurs with 44/16 files on my NAS, as well as Tidal 44/16 tracks.
This setting is primarily used when an S/PDIF, AES, or I2S connection is involved. Oftentimes, a DAC will take a little bit of time to lock onto a new audio signal–sometimes as long as a few seconds.
This setting causes Roon to play a configurable duration of silence whenever it begins a new stream. Like the last setting, this one is a problem solver. If you find that the beginnings of songs are being cut off, or you’re getting a lot of clicks and pops while your DAC locks on to an S/PDIF signal at the start of playback, try increasing this setting. 500ms is a good starting point. If that doesn’t work, try gradually increasing it from there.
We default this to a very small value because it produces delays in Roon’s user experience. Consider that when setting it up–unless you have an uncommonly slow DAC, settings longer than 1-2 seconds are probably not necessary.
Norris, thanks so much for your reply. I had tried that, but it had no effect no matter what I set the delay to. This afternoon, I was doing additional searching and got a hit for a Roon community post I had not seen in my prior search. This describes my current problem exactly. It seems to me the problem may lie in the Diet-pi Linux OS on the Allo USBridge. Do you agree?
Thanks Noris. When I connected the DAC directly to the Core and enabled it, Roon detected the DSD Playback Strategy as DOP. There was no Native option in the list. If I connect it back to the Allo USBridge and enable it again, Roon detects the DSD strategy as Native. If I change it to DOP, the issue does not occur. Although I would prefer to use Native, DOP is fine.
If you manually set the USBridge to DoP mode, do you still have this behavior? I believe you should be able to set the DSD strategy in the Allo’s Web Interface (by opening a browser to volumio.local or
You could also try the other suggestions here, witch is to have Roon upsample content to a specific sample rate such as DSD. You can toggle this kind of setting on in Roon’s DSP Engine -> Sample Rate Conversion.
The only place I see to configure DSD options in the Allo web interface is under Squeezelite settings, which I don’t use. If I set the DSD Playback Strategy in Roon to DOP, the noise does not occur. I can just leave it set to DOP in the Zone settings for the DAC in Roon. I prefer that to upsampling. Thanks
Glad to hear that DoP is working as expected for you and does not cause the noise. I spoke to our hardware team regarding this behavior and they have noted that in older Pro-ject firmware, this was a known issue.
That’s interesting to know regarding the firmware. I just purchased the DAC recently, and the firmware version reported on the DAC matches the current version on their download site. I think I’ll give flashing the firmware a shot. Otherwise, I’ll continue to use DOP. Thanks Noris.
I flashed the firmware again, and it didn’t resolve the issue with switching from FLAC 44/16 to Native DSD playback, so I’ll just stick with DOP. I found something interesting, though. I checked the ALSA stream when using Native playback, and again when using DOP. When using Native DSD, the stream was 88.2 kHz. When I switched to DOP, the stream was 176.4. I would expect it would be 176.4 for Native as well.
I don’t know if one can trust in the reported frequency here as it also reports using Altset 2 which is using format SPECIAL DSD_U32_BE and the DSD sample rates aren’t in the list of supported rates for the interface (Rates: …).
Btw.: A search for “0xb.0640” leads to other reports of clicks. Sadly no solution provided as I’m aware of. At least to me it looks more like a problem related to ALSA | Linux | drivers than Roon.
Thanks BlackJack. I appreciate your input. Looks like it’s a dead end. At least with the playback strategy set to DOP, at least it will switch from 44/16 to DSD without the noise even though the frequency is not right.