Raspberry Pi2b with NDAC - out of sync

Posted by: PatB on 09 June 2016

Hi All, 

Long time Naim user first time poster.

I've set up a Raspberry Pi2b with HIfiberry Digital DAC (transformer version) to stream music into a recently purchased a used Naim Ndac. After about 6min and 20secs music stops for about 0.5sec and then continues but the sync light on the panel switches off. The only time sync light remains on is with 24bit material. The issue I am describing happens with 16bit files only. I am streaming from a USB hdd. The DAC's sync light remains on with other sources (TV via optical for instance) and works fine using USB inputs (front and back). 

I've tested different inputs on dac, both optical and coaxial digital cables, I've installed Rune audio, tried Volumio, tried USB sticks, tried streaming via LAN (both PC shared folder and USB HDD connected to a router), tested with different power supplies, tried increasing buffersettings on Raspberry, disabled all possible unused features, tried both Raspberry Pi2b and Pi3b and, as you can see, I've ran out of options. 

Is anyone using a similar setup? Has anyone experienced this? 

When I bought the DAC it had rather old software that did not even play FLACs and I upgraded straight to the latest 4.11.8 version. Perhaps an earlier NDAC update, or doing updates incrementally, would improve things?

Many thanks!

Pat

Posted on: 09 June 2016 by Sloop John B

I had a similar issue with the Sonic Orbiter which is a Cubox based Pi device. I had a similar query from someone on another forum and here is my reply then.

The issue I had with the SOSE was the nDAC wouldn't show the sync light with it, well it did for about 15 seconds and then it went out and the light going out caused a 1-2 second silence, where the music was still playing but not coming through and then the music continued with the sync light not showing.

I asked on an Irish Hifi forum who are big in computer audio and XXXX who is also on the Naim forum answered

Not from experience, but the SOSE throws the clock-frequency of the SPDIF signal so far off the standard, that it doesn't match any of the 10 preset clock frequencies in the Naim DAC reclocker anymore. Naim DAC will switch over to a general reclocking algorithm in software which doesn't work as well as the cristal based frquencies.

Any device that will not sync properly with the Naim DAC, I would seriously doubt its quality and I would certainly throw it out.

When I emailed Naim I got this reply,

By the looks of the video and Email, you have an unstable clock from sonic orbiter digital output causing the Sync light to go out. This is a normal functionality in this event. As the source has an unstable clock output, the DAC compensates for this by switching to sample rate to make it stable.

I did ask if the sound quality would be affected by the compensation and was told

It’s just compensating for the unstable clock. So its running just as it should be, as long as it’s not interrupting your listening then its fine.

I wasn't overly comforted by this and reached the conclusion that the SOSE is predominantly a USB product with optical tacked on.

My Squuezebox Touch optical out worked into the nDAC.

 

I currently have a Raspberry Pi with hifibery digi+ which outputs digital into my UniQute with no problems. I couldn't live with the silence 15 seconds in and would always doubt the quality of the audio I was hearing with my acoustica nervosa, no matter what the chap from Naim said.

 

SJB

 
 
 
Posted on: 12 June 2016 by PatB

Many thanks for your input. 

These are the questions I would be asking as well. Interestingly enough, my friend has got the same setup (Raspberry Pi2b + Hifiberry Digi+ and Ndac) and it works without any interruptions. The last piece of the puzzle for me is the Hifiberry itself, it might be faulty. I have ordered a new one (without a transformer) to see whether it makes any difference and will, at some point, borrow my friend's setup to test each piece of the chain one by one. 

I will feed back once I have more info. 

Best, 

Pat

Posted on: 26 July 2016 by PatB

Hi All, 

After many hours of troubleshooting (different signal cables, power supplies, files, input sockets, different Raspberry Pi boards, different software players, older Ndac software, network streaming, memory cards, hard drives - basically everything to eliminate all other variables) it seems like the 44.1kHz clock on Hifiberries are not made equal (are of equal quality?). Ndac seems to work fine with some hifiberry boards (with or without transformer, v1.0 or v1.1 makes no difference) but not with other. Between my Ndac setup and my friends Ndac setup we tested 5 boards. Only one of all the boards worked properly with my Ndac and only two worked on my friend's Ndac (the only difference is that his Ndac has the beta version of the latest software). The remaining three did not work on either of our Ndac's - sync light came off and music stopped for a second.

When it works, it works really well and I can't really fault the sound quality. Unfortunately, you need to be lucky enough to find one that works...

Best, 

Pat