Sync'ing wordclocks of 3 pieces of gear... Can I daisychain?

I have a MOTU 828 MKII, and a Behringer ADA8000 hooked up to that via ADAT. The wordclocks are synced via one BNC coax cable. I plan on buying another preamp (Aphex 207d) to connect to the MOTU via SPDIF. Will I be able to sync the wordclock somehow to the MOTU still?

I'm thinking maybe i'd sync the wordclock of the Aphex 207d to the ADA8000 (through a BNC cable again), an then the ADA8000 is synced to the MOTU 828 MKII?

Or do I need to buy some other piece of gear to be able to sync these all up at the same time?

Thanks in advance...

Dave

ORIGINAL: losguy

The WC input on the ADA8000 is unterminated, and the Aphex WC is terminated. That means that you can easily daisy-chain the WC with a BNC Tee and two 75-ohm cables. Look at Fig 4.5 in the ADA-8000 manual. You would set up the MOTU as the WC Master, and the ADA-8000 and the Aphex as slaves. Feed the ADA-8000 from the MOTU as shown in Fig. 4.5, using a Tee connector. But instead of the terminating resistor, run a second cable from the Tee directly to the Aphex. No terminating resistor is needed, because the Aphex is internally terminated. Keep the cables short (less than 2 feet if you can) and you should be good to go.

Awesome! Thanks for the very detailed answer... very much appreciated... Now I can order in the Aphex 207d confident that it'll work with my existing setup... nice...

Dave

ORIGINAL: losguy
I'm going entirely on specs and prior experience. Based upon that though, it looks like it should work.

I have a similar setup with a fireface 800, ADA8000 & ART DPSII connected exactly in the manner losguy describes and it works very well. If it doesn't, you could always sync the ADA to your MOTU via lightpipe and clock the Aphex directly via WC. You'd pick up the 8 analog outputs on the ADA in the process. In either case, one (or more likely both) of these methods will work for you.

ORIGINAL: newfuturevintage

ORIGINAL: losguy
I'm going entirely on specs and prior experience. Based upon that though, it looks like it should work.

I have a similar setup with a fireface 800, ADA8000 & ART DPSII connected exactly in the manner losguy describes and it works very well. If it doesn't, you could always sync the ADA to your MOTU via lightpipe and clock the Aphex directly via WC. You'd pick up the 8 analog outputs on the ADA in the process. In either case, one (or more likely both) of these methods will work for you.

Yeah... My first ADA8000 is connected to the MOTU via ADAT already (how the audio is sent into the MOTU from the ADA8000)... Before I synced the two WC's together, I was able to record, but there was crackling and popping with the recorded tracks. Once I used the BNC cable to sync the wordclocks, the crackling stopped on the recordings... So the ADAT out on the ADA8000 is in use right now... But are you saying I could get another lightpipe cable and go from the ADAT out of the MOTU into the ADAT in on the ADA8000 and sync the wordclocks like that?

And THEN use the BNC cable to sync the wordclocks of the aphex and the MOTU?? I already have another ADA8000 that I used to "bridge" it's own adat with... i.e. took one optical cable and put it in the input AND output of the ADA8000 (ADAT) and then I used the behringer as a standalone pre-amp... Ran cables from the back of that into the analog inputs of the MOTU... so now, I have in the front of my rack, 18 preamps, all running into the MOTU... With the APHEX i'll have 20... well, sortof... there's only 1/4" on the front of the Aphex, but yeah...

Dave

OK.... I picked up the Aphex 207d today.... Went to a local electronics store and bought a BNC Tee connector. This connector had basically two female ends (the top two ends of the "T") and one male end (the bottom of the "T")... I also picked up an extra BNC cable...

That said, I plugged the male end of the BNC Tee connector right into the MOTU 828 MkII Wordclock OUT... I then took the two BNC cables I had and plugged them into the female ends of the "T", and the plugged each one into the Wordclock IN for both the ADA8000 and the Aphex...

Immediately on the ADA8000 the LED lights up right above "LOCKED"...

I plugged a mic into both the Aphex and the ADA8000 and tested stuff out in Cuemix, and I'm getting audio from both... Did a test recording in SONAR and it played back fine...

The only time I got errors in Cuemix was when I tried to record in low latency with FX enabled (and input monitoring turned one)... I'm not surprised the MOTU crapped out, and I assume it has nothing to do with the wordclock sync... I turned the sample buffer back up to 768 and slid the latency up to 53 and it could record fine and playback fine after that...

For the SPDIF audio output, I just bought a THX certified Digital Coax (RCA) cable... i'm assuming that was correct since the Aphex is sending audio through it to the MOTU...

So yeah, does it sound like everything is sync'd up as it should be? or maybe it's not in sync and I just don't know it yet?

Dave

ORIGINAL: losguy

Actually, I recommended placing the tee on the Behringer unit, and running cables from the tee to the MOTU and the Aphex. It's technically more correct to do it that way. You could try it the "correct" way in case you run into problems.

But if the MOTU can drive a 37.5 ohm load, and the reflections off the (unterminated) Behri are not an issue, then the way you have it now is probably OK.

Ah... I misunderstood... you're right... now that I look at figure 4.5, it does make sense to do it the "correct" way... my bad...

:)

Can't wait to try it out... I figure now i'd get the best sound out of the Aphex pre's, and then the second best out of the Motu pre's, and then the ADA8000 pre's connected via ADAT, and then finally the ADA8000 connected via the analog inputs on the back of the MOTU.

That means to me, that if I was multitracking a band, i'd put the tracks that I want the most focus and quality for, on the best pre's first, then work my way down... I guess too, it's not a matter of the pre's being better or worse, but more using the ones first that go through the least amount of A/D D/A conversion... For the ADA8000 (connected via analog inputs on MOTU) I guess it'd actually be A/D then D/A then A/D again... sheesh... At least, it gives me another 8 inputs...

Now all I have left to buy is an SM57 and i'll be all set for the most part...

Dave