iMac to nDAC - SYNC

Andy, back to the idea of putting the files on a usb stick.  The Naim Dac supports this -- playing files from a usb stick.  If you put the files on a stick and they can't be read . . . either the stick is bad or something else is amiss.  I do think that's a great way to troubleshoot.

sounds to me like the external harddrive might be broke. do you have a back up?

Bart

If you recall I tried this before but have tried again and an interesting result.  I copied an 88.2khz track to a usb stick, plugged it into the front port of the nDAC and as you say, it played fine.  Then deleted that track (manual says it plays tracks sequentially of USB) and copied a 96khz track - nothing at all from the nDAC.  Tried the rear port but likewise nothing.  Need to go to the office now and will try other sample rate tracks later, but would that suggest the nDAC has a problem?

Yeah, WAV files on the USB stick play sequentially, you just load them without putting them in a folder.  All sample rates should play if all is well.

That sounds like a Naim DAC problem, yes.  When I owned one, it played HDTracks files from a usb stick just fine (inconvenient, as you cannot see what tracks are next, but it works!)

Evening all, time for the result of tonight's tests.

I have selected 6 tracks, one of each sample rate I own above 44.1k, so we have tracks at 48, 88.2, 96, 176.4, 192 and finally 352.8khz.  I have then played each track three ways, either via a usb stick in the front port of the nDAc (with just a single track on the USB stick at a time); through my iMac/V-Link/nDAC and finally (having copied them to the USB stick and imported into the library of Fidelia on my MBP) through my MacBook Pro/V-Link/nDAC.  The tracks have been acquired from a variety of sources, namely 48 from B&W's Society of Sound, 88.2 from Linn Records, 96 & 176.4 from HD Tracks, 192 from Naim Label and finally 352.8 from 2L.  All bar the latter reside on my external hard drive.

And so the results.

All tracks played via USB on the nDAC played perfectly.

Turning to the iMac, sample rates 48, 96 and 192 failed (ie lost the sync light at some point), while the 88.2, 176.4 and 352.8 played perfectly well.

Turning to the Mac Book Pro - that produced exactly the same results as the iMac.

I think the USB result demonstrated the integrity of my hi-res files irrespective of either retail source or hard drive, so apologies to HD Tracks for suggesting that may not be the case with music acquired from them - I shall be buying more from them in future.

This does of course leave the iMac and MBP result.  I would like to think we can rule out the iMac/MBP as the problem since you would not expect two computers to have the same failing (for what it's worth, the MBP runs OSX Lion, while the iMac runs OSX Mountain Lion).  That said, I have of course also had the luxury of trying a replacement V-Link 192 and nDAC, albeit at that time we were still fishing a little in the dark.  I think there is now greater clarity that the problem lies with, or affects only, those files with sample rates as a multiple of 48khz.  However I still don't know where the problem lies; that the USB input on the nDAC is fine may not mean the BNC inputs are?

Is there anything else I can try?

Andy. Have you tried with a short USB lead - say a metre max?

Richard - that's one for me to try tonight, thanks.  Realistically I can only try a shorter USB with the MacBook Pro.  I also want to try an optical cable if possible from the iMac thereby cutting out the V-Link but not sure when I'll be able to get hold of such a cable - might ask Music Matters if they can loan me one.

Hi AndyF,

Music Matters are sending us a V-Link to take a look at ... the laid down specs for S/PDIF say that the clock drift on an S/PDIF signal should be no more that 100 parts per million and we can sync to a 200 parts per million drift (twice the specs) ... outside that we have to revert to sample rate conversion (which is what's happening when the "Sync" light goes out and you get a brief drop in audio and then it comes back but without the "Sync" light).

It sounds - from what you're saying and what Music Matters have told us - that the 48k and multiples clock on the V-Link is drifting quite badly so all being well we'll have a unit from them tomorrow and we can take a look at the timings from that unit.

Cheers

Phil

If you are connecting the same external drive to both macs, my original statement remains. If you are copying them to the macs first, I am stumped.

Richard - tried the shorter USB lead and made no difference.

Phil - appreciate you looking at this and will wait to hear back from you.  Music Matters may have told you we tried two examples of the V-Link 192 and got the same result, whether that suggests a dodgy production batch or design I'll leave to others to comment on.

Regards

Andy

Phil

Is an alternative route to simply bypass the V-Link and take a optical digital cable from the iMac to the nDAC?  The headphone outlet doubles as an optical digital output but I have no idea whether you can get such a cable (would also need ot be around 7m long).

Andy

Andy, folks here who use the Mac Mini into the Naim Dac seem to universally prefer the Mac Mini's optical output.  And definitely that is one less piece of hardware that can go wrong.  I have no idea whether other Mac's do optical as well as the Mini, however.

If your Mac has an optical output then you can take that straight into the Naim DAC however you will be limited to 96kHz as a maximum sample rate due to the limitations of optical cables / transceivers and you'll almost certainly not get it to be reliable over 7m - best I've done *RELIABLY* is about 5m.

Cheers

Phil

But at least if Andy tries playing 48 and or 96kHz stuff via optical and it works he will know that the nDAC is ok via spdif. Moving a mac for a few minutes and using a short lead would be fine for such a revealing experiment.

Phil

'however you will be limited to 96kHz as a maximum sample rate'

So that's a 'no' then.

Likesmusic

Agreed but it would be a pyrrhic victory since having invested in an nDAC, I want to play music at higher sample rates than 96khz - and reliably so.  I just hope Phil / Naim can come up with a solution - if it is the V-Link, what to do about it.

Regards both

Andy

Andy - my suggestion was not intended to be a permanent solution, just a quick and easy way of giving the guys at naim more information to help them with a cure. If 48 and 96 work via spdif from a different source then that would indicate the VLink is more likely to be culpable, if otoh there are still issues then they would be more likely to suspect the VLink or something else.

Why is nothing easy?

Bought a Toslink - min-Toslink adapter.  Hooked up the MacBookPro with the 6 tracks on the USB stick.  Of the 6 tracks only the very large 352.8khz wav file would't play at all.  The rest all had the sync light on which is great.  However note now that the 96 and 192khz tracks have the HD light on, while the 48 (as expected), 88.2 and 176.4khz tracks do not.  Why?

I then take the USB stick out of the MBP and put it straight into the nDAC and toggle through each track and all bar the 48khz (again as expected) have both sync and HD lights on.

Hi Andy,

I'm not in the office at the moment but from what I understand I believe there's a v-Link on it's way back up from us to Music Matters that will not exhibit the same issue...

Phil

Were you changing the output S/PDIF format from the AppleMidi app to match the sample rate of the files that you were playing?

Phil

Thanks for the two posts Phil - looking forward to the V-Link.

Within Fiedlia Preferences / Output I had the sample rate set to 'match song'.  Looking further, within Midi I see the MBP has three sample rates listed of 44.1 48 and 96.  If I fix the sample rate at 96 then everything lights up as HD.  If I set the sample rate as 'Match Song' you can see when a 88.2khz or 176.4khz track is played the clock speed displayed in Midi switches to 44.1 and so the HD light goes out.  That then would appear to be a quirk or failing of the MBP.

Phil,

Thanks for sorting out the V-Link 192, all sounds great now and I really appreciate the effort you guys have put in.  I've read the service sheet so thanks for going the extra mile to get the thing working correctly - I gather Music Matters are going to have a word with Musical Fidelity as clearly they have a problem which they need to be aware of and deal with.  When registering Naim kit, at the point the survey asks 'is there anything else we can do' perhaps I should have put, 'make an asynchronous USB-B adapter'.  

The V-Link is rated to 192khz; the nDAC will of course go way beyond that, which begs the question of how to get there from a Mac... 

Cheers Phil,

Andy.

I'm not saying anything here - but yes, you have the service sheet and nothing's been changed on your DAC.

Actually, the DAC will "only" go up to 24/192 by S/PDIF as that is the limit of electrical S/PDIF ...

We do - it's called a DAC-V1...

Cheers

Phil

Hi There, Phil, AndyF.

I was searching the internet for this problem.
My Dad has The V-link 192 & Naim Dac. 
And suffers from exactly the same problem as described in this topic.

44.1 khz and multiples works as should.
48 khz and multiples give sync loss after a certain amount of time.

What exactly has been done to the V-link 192?? 
What about the 'service sheet'?
And what the way to go to fix this.

Regards
Sebastiaan