If you have outboard converters and use LightPipe to sync...

[T-Dogg]

Lemme tell ya' a little story!

I use nuendo with a Hammerfall card and separate AD and DA converters. Everything was connected via ADAT LightPipe (as is typical with most Digital Audio cards), and I was perfectly content to use the embedded sync carried in the subcode of the LightPipe signal to sync everything up. Nice and simple.

Problem is, i always thought I noticed a slight difference between audio monitored from the soundcard's out during recording, versus the way it sounded playing back. Always seemed to be a little hazier, and little less defined in the highs and soundfield. So I started wondering if this was jitter, my imagination, whatever...

did a little reading, and from what I could find out, LightPipe is not bidirectional -- it only transmits data in one direction.. this goes for the subcode too. The sync reference is embedded into the stream by the device generating the stream. For my system, this meant that:

--When recording, the nice internal clock on my AD was clocking everything via lightpipe...

--When playing back, the inferior clock on the Hammerfall (maybe not bad, but certainly not as good as that on the AD, especially considering interference in the computer chassis) was doing the clocking. Verified this by bridging the AD/DA wordclock connections, and seeing that the DA has dropouts on playback and playback only...

So I went out and bought me some wordclock cables and synced everything up with the AD as master. And now all the differences that I thought I heard, but couldn't explain are gone. It sounds better, I don't hear that hazyness in the imaging and high frequency nonsense during playback anymore. And it makes me mad thinking about all the time I invested in trying to \"mix\" out a problem that only existed in my DA conversion.

So to those of you with similar setups, ya' might wanna try wordclock -- it's definately not night and day, but certainly the best $35 investment I've made in a long time. Even if there's not a huge quality difference between the clock in your soundcard and converters, at least there's the piece of mind in knowing your record and playback clocks are one in the same.

 

[Michael]

Yes clocking issues can sometimes drive you crazy Glad you sussed out the issue .

 

[geekeye]

i'm not going to argue against using wordclock, but if you have optical cables going in both directions, your ad/da should be able to get its clock from the audio interface with no trouble.

 

[T-Dogg]

Agreed, and there was always a stable clock reference, but the problem I had was that my DIGI32 card seemed to generate the clock on playback when in \"Autosync\" mode. Maybe because I was using separate AD and DA converters, is was more of a \"Loop\" situation as opposed to a normal Full Duplex setup. I dunno, might be more of a Hammerfall thing than a general rule, but the bottom line was I always wanted my AD to do the clocking, as the playback quality of my DA was better using that clock as opposed to the Hammerfall's... Word Clock was the only way I found to make this happen...

 

[neil wilkes]

Wordclock really does seem to be a better solution.
It's almost like having your windows cleaned - you could see okay before but now it's all much more detailed.

Same thing seems to apply with W/C.

 

[esKEBAB]

Hey.. I found this thread quite interesting.. I dunno if my problem is really related, but quite often, and its rather annoying, when I select Audio Instrument tracks in Logic that are routed to a bus which has a uad-1 plugin on it (also delay comp), the sound occasionally starts messing and it ends up sounding bit crushed - followed by an error message saying 'error syncing audio and midi'.. In the settings control panel I have it set to 'master sync' at 44khz.. strange that it only happens when I select instrument channels, not audio..