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clock setup sanity check

PostPosted: Tue May 16, 2017 5:50 pm
by arjepsen
Hey.
I just got myself a new interface (Motu 1248) and I just want to check up with you guys, whether I'm connecting things right:
I want to use the Motu as the clock master. I got a bnc T-junction, that I put on the output of the Motu. Then I connect one side of the T to the input on the apogee clock card in my d8b, and the other side of the T to the input on my HDR, with the button depressed.
If I understand correctly, I don't need any bnc terminators in this setup..... is that right?

Regards
Anders

Re: clock setup sanity check

PostPosted: Tue May 16, 2017 7:12 pm
by captainamerica
I don't use a HDR but I have a MOTU 2408 and use it as a SLAVE...make the d8b the master in your chain

I uploaded my MOTU 2408 setup which might not be relevant to your setup

Re: clock setup sanity check

PostPosted: Tue May 16, 2017 7:33 pm
by arjepsen
Thanks, but I'm not too keen on using the d8b as the master - people seems to describe the apogee card as having a somewhat low output signal.
But I'm more asking about the whole termination thing... not entirely sure whether I need T's and terminators, or not.

Re: clock setup sanity check

PostPosted: Tue May 16, 2017 8:08 pm
by captainamerica
Never had any low-voltage issues with the Apogee card but that doesn't mean there aren't any are problems.....will defer to the forum on this one.

As for Ts..."in theory", terminators are placed at the end of a transmission chain and are designed to match AC impedance. Not sure whether that is applicable to your setup, but I will defer to the forum on this as well.

Re: clock setup sanity check

PostPosted: Wed May 17, 2017 12:22 am
by anyhorizon
If you want to use the 1248 as master clock, you should first run it to the HDR (in unterminated mode) and BNC "T" from there to the d8b. The d8b Apogee Clock Card is automatically terminated which is a PITA. There's a post I put in the database to make it switchable but I doubt you'd like to go that far.

Peter

Re: clock setup sanity check

PostPosted: Wed May 17, 2017 10:21 am
by arjepsen
One thing that annoyed me was, that I could get several setups to work, but only if all three devices was on. The d8b as last in the chain wouldn't get a lock on the clock if the HDR wasn't turned on.

Re: clock setup sanity check

PostPosted: Wed May 17, 2017 3:40 pm
by Dreamsequence
Try turning the d8b on first, and let it boot completely. Then turn on the other devices. See if that makes a difference.

As far as the stability and output level from the Apogee card, it should be more than adequate. It is likely a better source for Master Clock. Make sure the termination button is Off or up (out) on the HDR. The other thing is to watch out for a) the wrong type of coaxial cables, and b) exceeding the recommended cable lengths. The information is in the tech manual, and I believe the Owner's Manual for the d8b.

You indicated this won't work unless all three devices are turned on; which ones are you attempting to use together?

Pat