Clocking issue -- mac audio output (optical) to 96k PT session (192)

[jeremyroberts]

As a newbie to 96k, learning that I must be doing something wrong...

If PT session is @ 44.1, clocking to external wordclock, I can simply take the optical out of the mac, and route it to optical [encl] in on the 192, and listen to mac audio just fine. iTunes, browsers, anything that is mac system audio goes out optical, and into the 192. make an aux. Listen to the mac. Happy.

However, if the PT session is 96k, static -- clocking issues. Is there a clicking setting somewhere? How do you guys do this @ 96k?

Thx

J

[DigiTechSupt]

Is your Wordclock source also set to 96k?

I think there may be something wrong about your configuration - all devices must be clocked to the same source so, in your case, since the Mac doesn't have a Wordclock input, you should run an optical cable out of the 192 to the in on the Mac and set the Mac to clock to that input. Assuming your Wordclock source is at 96k and your 192 is set to 96k, the Wordclock will get translated to optical to the Mac and everything should sync.

[crizdee]

Originally Posted by jeremyroberts

As a newbie to 96k, learning that I must be doing something wrong...

If PT session is @ 44.1, clocking to external wordclock, I can simply take the optical out of the mac, and route it to optical [encl] in on the 192, and listen to mac audio just fine. iTunes, browsers, anything that is mac system audio goes out optical, and into the 192. make an aux. Listen to the mac. Happy.

However, if the PT session is 96k, static -- clocking issues. Is there a clicking setting somewhere? How do you guys do this @ 96k?

Thx

J

Hi Jeremy,

Have you tried in the AMS setup,

On the new MacPros the internal can go to 96k...



At the bottom of the AMS page there's a small cog where you can select to use the revenant input device



Chris

[jeremyroberts]

Originally Posted by DigiTechSupt

Is your Wordclock source also set to 96k?

I think there may be something wrong about your configuration - all devices must be clocked to the same source so, in your case, since the Mac doesn't have a Wordclock input, you should run an optical cable out of the 192 to the in on the Mac and set the Mac to clock to that input. Assuming your Wordclock source is at 96k and your 192 is set to 96k, the Wordclock will get translated to optical to the Mac and everything should sync.

Hi DTS,

My external clock does not do 96k, so for the few sessions I have to work 96k, I trust the internal clock of the 192 won't suck too much. I am not using my Giga rig on the 96k sessions, so there is no reason why the 192 internal clock can't be master clock for the sessions that are 100% in 1 box. Right?

My routing of the optical is FROM the mac TO the 192 enclosure.

Are you suggesting I also route optical FROM the 192 back TO the mac optical in as well?

Hmm... that may be difficult as I am also using the optical enclosure output to feed a Nicecast stream --

Hold on... re-reading your post:

and set the Mac to clock to that input.

How would this be done? Is there a mac sound/audio pref. AMS? Only goes to 48k (I'm on G5 2.7 for this).

I'll try simply plugging 192 back to the mac (round trip) and see if anything changes.

Thanks.

J

[jeremyroberts]

Originally Posted by crizdee

Hi Jeremy,

Have you tried in the AMS setup,

On the new MacPros the internal can go to 96k...



At the bottom of the AMS page there's a small cog where you can select to use the revenant input device



Chris

Thanks Chris,

But I am constrained to 48k (G5 2.7)

I tried the round-trip (192 enclosure optical out ==> Mac optical in) and that made no difference. Next post replies to DTS.

[jeremyroberts]

Originally Posted by DigiTechSupt

Assuming your Wordclock source is at 96k and your 192 is set to 96k, the Wordclock will get translated to optical to the Mac and everything should sync.

Tried home-running the 192 optical out back to the mac. No change.

My routing is simply:

mac optical output -> 192 optical [encl] in
192 internal clock @ 96k

And this does not allow playback without massive clocking errors.

It was my understanding that the 192 [encl] inputs were supposed to be real-time SRC , yes? But that doesn't solve the clocking. Hmm...

What did you guys do working 96k before you got your MacPros?

[Sean Russell]

We'd go out analog to an unused stereo input on the console (1/8" to TT's)

[crizdee]

Originally Posted by jeremyroberts

What did you guys do working 96k before you got your MacPros?

I used a M-Audio Super Dac 2496


Chris

[Danny Caccavo]

Unfortunately, the Mac Pros (unlike the G5's) cannot lock their digital output to their digital input. They basically botched something in the Mac Pro design.

The reason why you don't get clicks when outputting the mac into the 192 (when the 192 is clocked from another wc source) is pure luck, as both the mac and the 192 clocks are running "close enough" for you not to notice clicks. However, if you start using pulled down sample rates, you are SOL for doing this.

There's a nice feature on the Omni where you can SR convert the lightpipe input. Unfortunately, we've got 192's to deal with, and on those you cannot SR convert the built-in s/pdif input, and I don't believe the digital card optical input accepts 2-channel S/PDIF -just ADAT, so there is no elegant solution to get the mac audio into Pro Tools digitally. I, for one would not feel comfortable locking Pro Tools to the Mac clock....

dc

[crizdee]

Hi,

Best thing to do is get an external soundcard for this! a basic firewire or USB with word clock and digital i/o would work fine.

I use a firewire Tascam 1804 just for these tasks and for streaming Logic into PT via ADAT. all works sweet up to 96k all clocked from the 192



Chris