RPi + HifiBerry Synchronization Problems

I’ve only seen old mentions of this problem, which is new to me.

I have a total of four RPi 3’s with HifiBerry boards running the indicated HifiBerry version.

Digi+ (1.2.2)
DAC+ Pro (1.3)
2 DAC+ (1.2.2)

The DAC+ Pro was added at almost exactly the same time as the Roon software went to version 1.3 and the problems starting happening about then.

The issue is that the sound synchronization gets off if I have 3 or more of these endpoints in a group. If I have only 2, no problem. The Digi+ is always in the mix and if I add one of the DAC+, fine, but if I add another, then synch gets off.

All but one of the endpoints have volume control hidden in Roon.

There are some settings in audio setup which seem to be pertinent, but I am looking for a place to start.

Do I need to adjust Clock Master Priority? Resync Delay? Try different Roon software?

Thanks, everyone. I appreciate the consideration.

Can you confirm that all devices play simultaneously when not grouped?

Yes, they all play simultaneously just fine when not grouped. 4 distinct and apparently perfect streams.

Just a thought…are they all on wifi or wired or a mix?

I have noticed in the past a similar thing with RAAT endpoints in groups on some RPi and other setups in the mix too that sync starts to drift when the device count is more than 2 IIRC. Sometimes I think over a prolonged session even 2 starts to drift off…even when the 2 endpoints are the same (2 x 2010 MacMini (roon bridge) and 2 x XMC-1 Processors both via USB or both via HDMI - but I would have to go back and revisit that as its was pre 1.3 I think.

I do have a few RPi units I can play with with IQAudIO DAC/AMP setups so that could be more in line with your setup to replicate too…If I get time to do some testing I will.

The reason I asked was in case you had imaged your builds rather than crated them individually (which has recently been highlighted as an issue.)

I did use the HifiBerry image and just burned each one without modification. I definitely did not build them from scratch. They all work fine, show up separately, the whole shebang.

They are all on an Ethernet over powerline network, dedicated to this network and connected directly to the Mac Mini (Mid 2011, 8GB RAM, OS 10.12.2) running Roon solely. There are never any skips or dropouts, and prior to recently, no sync issues.

I for sure have never seen 2 points drift off, but adding a third means within 3-5 tracks things are out of whack.

Sorry, what I meant to say was that you didn’t clone the disk image after you set up Roon and then copied it to another rPi. My thoughts were that maybe you had the same unique id on more than one device (which Roon issues/creates as part of the Roon installation) and that this might be causing the problem.

I get you. No, I did not clone the disk image for any of them. All freshly baked!

Have you tried different bitrates…if higher ones show issues and lower ones not maybe its some bandwidth issue?

My typical use is mixed playlists. I either create something on the spot or use radio (until it starts cycling f’n Ryan Adams and Neko Fox as it almost inevitably starts doing. . .but the sucky radio feature is not the problem today) so it’ll be a mix of Tidal, very few MP3 files, some High Res and a lot of ripped ALAC files. I’m not sure bandwidth is an issue.

Perhaps try the clock master priority.

Interesting. I will play with these settings.

Hey everyone, I seem to have fixed the problem I was having with synchronization. The answer seemed to have been setting clock priority in the Zone Grouping tab of Device Setup. I assigned each output a priority number instead of leaving it as default and now it’s working well. Who knows why, but it appears to be a solution.