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[Stuart Pendleton]

I used the Audiorail system for a show Saturday night. It worked fine.  It was a joy to only deal with CAT5 instead of 40 channels of analog snake and other sub-snakes.  I did have one major issue due to my lack of research.  The output of the DA converter feeding my amps was only 16dbu whereas the 01v96 puts out 24dbu.  It caused me to run the main fader MUCH higher than I like to.  I corrected that yesterday and bought a Lucid 8824 converter that should integrate better into the system.

The cheap ART clock did OK (which was my original question) but I still have concerns trusting the ART unit so I bought a Lucid Genx-6 clock that is a nicer piece to replace it.

Now the question:  I can make the 01v96 the master clock and send it over ADAT to the Genx clock for re-distribution over BNC cables to the 2 Presonus D8s, and the 8824 converter. I can also make the Genx the master and send clock the same way.  The last choice is to let a Presonus D8 be the master.  Of these possibilities, which way would you set it up?  I am leaning to the Genx as the master as first choice, 01v96 as second choice, and a D8 as last choice, although everything I read says that the converter doing AD (the D8s) should use it's internal clock if possible.  I could do that, but don't have the real world clock experience to make the call. I know Mac has said before he would never have the clock come from any source other than the console in a previous Audiorail thread, but it seems like loss of clock from anywhere means failure since no analog inputs go the 01v96 anyway. In that case, shouldn't I just try to get the most reliable clock possible i the job?

What would you make the master in this situation? I don't want to have to change the racks repeatedly.  Anybody have any first hand experience to impart here?

[Rob Spence]

My $0.02
I would use the 01V96 as master, send BNC clock to the Genx if you need to though I dont understand why you need an external clock at all.

[Stuart Pendleton]

The Audiorail doesn't have BNC and I didn't want a 150 ft long WC cable. Sync had to be through ADAT and the D8s don't an ADAT in so I had to have a clock to sync them to each other, then let one of them send ADAT to the console so it could sync.

[Andrew Hollis]

The Audiorail doesn't have BNC and I didn't want a 150 ft long WC cable. Sync had to be through ADAT and the D8s don't an ADAT in so I had to have a clock to sync them to each other, then let one of them send ADAT to the console so it could sync.

The D8's have WC IO, so you could pick one as master, WC out to the next one, WC or ADAT out of that to the console or 8824, WC out of that to the 8824. With small, personal setups (fewer than 6 pieces maybe) I find there is no need for dedicated clock distribution. That said, I'd probably pick the console as master and daisy chain off that.

If you do enough clocking permutations, you'll find some that don't work at all. Everything else is fine.

A diagram of your setup and how far away things are would make recommendations easier.

[Stuart Pendleton]

The D8s do have word clock IO but not in a way that can work here.

It has a BNC in only.
It has wordclock out over ADAT.




There is nothing else.  I can and did pick the first D8 as the master but WC out is only via ADAT and next D8 does not have ADAT in so without a clock/distribution unit you cannot sync them.  That is where this was falling apart. You can't sync one D8 from another D8.

[Matt Tudor]

I used the Audiorail system for a show Saturday night. It worked fine.  It was a joy to only deal with CAT5 instead of 40 channels of analog snake and other sub-snakes.  I did have one major issue due to my lack of research.  The output of the DA converter feeding my amps was only 16dbu whereas the 01v96 puts out 24dbu.  It caused me to run the main fader MUCH higher than I like to.  I corrected that yesterday and bought a Lucid 8824 converter that should integrate better into the system.

The cheap ART clock did OK (which was my original question) but I still have concerns trusting the ART unit so I bought a Lucid Genx-6 clock that is a nicer piece to replace it.

Now the question:  I can make the 01v96 the master clock and send it over ADAT to the Genx clock for re-distribution over BNC cables to the 2 Presonus D8s, and the 8824 converter. I can also make the Genx the master and send clock the same way.  The last choice is to let a Presonus D8 be the master.  Of these possibilities, which way would you set it up?  I am leaning to the Genx as the master as first choice, 01v96 as second choice, and a D8 as last choice, although everything I read says that the converter doing AD (the D8s) should use it's internal clock if possible.  I could do that, but don't have the real world clock experience to make the call. I know Mac has said before he would never have the clock come from any source other than the console in a previous Audiorail thread, but it seems like loss of clock from anywhere means failure since no analog inputs go the 01v96 anyway. In that case, shouldn't I just try to get the most reliable clock possible i the job?

What would you make the master in this situation? I don't want to have to change the racks repeatedly.  Anybody have any first hand experience to impart here?

Generally, I get nervous clocking a digital board off another piece of equipment. I know my LS9-32 quits passing signal and freezes up if it loses an external clock source and has to resync to it's internal clock. I'd guess it's not the only board that does this. In your case specifically, though where everything is digital(and therefore very dependent on wordclock) I'd hook everything up in the shop and see what source causes the greatest  amount of down time to lose. Some devices can re-sync or change sources quickly without much more than a couple pops. Something like that can clock off of anything. Some devices (like my Ls9) takes a couple seconds and it's complete silence. Choose the device that causes the greatest service interruption and protect it by making it the source.

[Stuart Pendleton]

Matt, that makes sense.  I think the safe route is make the 01v96 the master, and let it send clock to the 8824 DA converter that feeds the amps, since I shouldn't lose clock sync unless I also lose ADAT output, which means audio is down anyway.  The 8824 is able to accept ADAT sync in, parse clock out, and then pass that clock out through it's BNC.  I could feed that signal to the Genx since it can function as a distribution unit.  I would expect that the odds of losing sync over the ADAT output stream are greater than that of losing sync with hardwired BNC connections.  Does this sound like a good place to start?

Thanks for the thought!

[Rob Spence]

The D8s do have word clock IO but not in a way that can work here.

It has a BNC in only.
It has wordclock out over ADAT.




There is nothing else.  I can and did pick the first D8 as the master but WC out is only via ADAT and next D8 does not have ADAT in so without a clock/distribution unit you cannot sync them.  That is where this was falling apart. You can't sync one D8 from another D8.

You can just use BNC Tees on each and sync the pair from another source such as the mixer or the 8824 . WC isn't chained together via in and out connectors. It is a transmission line.

The last unit should have a terminator on the Tee.

I like using goal post style tees as the wiring is easier in a rack.

[Stuart Pendleton]

That is what I am doing. The Audiorail doesn't support WC over BNC, just through ADAT so I bought the Lucid WC to send signals to these guys through a BNC chain.

[Matt Tudor]

Matt, that makes sense.  I think the safe route is make the 01v96 the master, and let it send clock to the 8824 DA converter that feeds the amps, since I shouldn't lose clock sync unless I also lose ADAT output, which means audio is down anyway.  The 8824 is able to accept ADAT sync in, parse clock out, and then pass that clock out through it's BNC.  I could feed that signal to the Genx since it can function as a distribution unit.  I would expect that the odds of losing sync over the ADAT output stream are greater than that of losing sync with hardwired BNC connections.  Does this sound like a good place to start?

Thanks for the thought!

Upon further contemplation, I have another thought to throw out. A couple shows ago we had our normal LS932 with a Presonus preamp set up plus we added a small recording rig. Recording rig was  direct outs on the 16ch ADAT expansion card to a Profire Lightbridge feeding a MacBook running Logic for recording. Word clock master was the board, preamp was slave via BNC cable, Lightbridge took word clock from  the ADAT since it has no BNC clock input.
The Presonus preamp was happy all night long, always synced to incoming 48K clock. The recording computer however kept stopping the recording, always complaining about detecting a word clock that it didn't recognize, usually 47.5 K. We haven't had this issue in the past, but this was the first time I've done all 16 channels at 48K. I've done 8 and 12 channels just fine, and the rig tested OK when I tried recording a stereo track earlier that day. What I'm wondering is if all 16 channels being full plus word clock was to much......maybe too much bandwidth???
Perhaps someone who knows more about word clock distribution can chime in, but is there any concern with mixing the word clock and ADAT signal?  Is there a way that some could get bogged down somewhere?

[Stuart Pendleton]

I wouldn't think so.  On the Saturday show I was sending WC to the Presonus units from an ART clock and they were fine all night.  I had to let the board send take WC over ADAT from the Presonus because I did not want to run a WC cable next to my 150 FT cat5 cable.  I was sending 16 channels of input plus the WC one way, and sending 8 channels of output the other way also with WC to my output converter over ADAT.  The entire system was stable all night without a single pop, click, or error message.

[ProSoundWeb Community]