Anyone know how to route Mac Pro Digital Output into 192 I/O

[Oakdale Post]

I use Soundminer for SFX and Music searches. For years I've used the mini plug line output of the Mac for auditioning sounds. I got to thinking, there must be some way to route the Mac digital output into a 192.
Has anybody done it? And if so, what is the method you use.
Thanks!

[Mr.Ed]

The new Macs cannot be locked to external word clock. What this means is that if you connect the mac to the 192 optically you will need to set Ptools to external digital clock (resolving from the mac)

While it is doable, there is probably many people that would be uncomfortable with the mac providing the clock source for the ptools system.

If you do want to do this, connect the optical cable to the main aes/spdif connector on the rear of the 192. Then in hardware setup specify the input 1/2 to be the digital optical input. Then set the mac sound output to be digital optical output, connect the appropriate optical cable. Set protools session setup to digital input from the spdif/optical port for the clock source.

This should get you going.

[Eric Lambert]

^ That's absolutely incorrect.

We use SoundMiner and our preferred method for auditioning sound is via the digital output of the Mac into a 192 via optical. It's exactly what the OP asked for and it's exactly what we do, and we don't need to change PT's clock in the process. No pops or clicks whatsoever. Anyway, it's just a path for auditioning sounds - the actual audio is automatically imported from the disk into ProTools - so total integrity isn't crucial.

To the OP: again, an optical cable from the Mac to the 192 does the trick. Obviously you'll need to have the 192 set to monitor that digital input. We have an Aux track within every session simply called "Mac" which is set to listen to that optical cable and muted, but we can un-mute and monitor easily and at any time.

[Oakdale Post]

Eric,
What is your Clock source? I'm using a Sync I/O referenced to Black burst Standard def

[Mr.Ed]

I am disappointed that one would dismiss my post and label it incorrect without obviously reading it. While the posters method of auditioning mac audio via optical without changing the session clock source works for him. He is auditioning a unlocked digital audio source. Glad to know that works for him, but it sure does not for me and my purposes. A hack is a hack, it may work but its still a hack.

[Oakdale Post]

Look guys I'm not trying to start a war here. But do know that Eric correct in that this is just for auditioning purposes, actual audio is transferred from Hard disc to session.
In my TV and video sessions I am always clocked to video ref (Black Burst) as I am working with short :30 second commercials to 9 minute corporate videos with on camera talent, testamonials, and the big cheeses of the Corporation, so I need to be referenced to BB to avoid Lip Flap.
There is usually ISDN involved as well.
I will go into this in more detail a bit later as I am still building this system from and Original Mac Pro in 7.4 and have made a big step into the new Mac and 8.0.4cs2.

What you may be referring to Ed is music based sessions while Eric maybe involved in Post.

Regardless, I appreciate both of your input.

[crizdee]

Hi,

I have been routing the digital out of my mac for years with no issues! and with the new mac pro's you can even work at 96k. you simply go to the AMS and select the digital out as the "device to use" and then set an input for optical, in the PT hardware setup page.

Yes technically the mac should have some clock to be 100% accurate, but it doesn't have any external clocking facility so it seems to be a bit hit and miss!! as some of us have no problems and others get pops and clicks. guess i'm one of the lucky one's

I recommend getting another USB/firewire interface solely for getting sound out of the mac! for the cost of a basic 2x2 interface it will sort a lot of problems!!

As Rail as indicated in the past, Soundflower doesn't output an exact correct frequency, so it will work for some and not for others.


Chris

[JFreak]

If you connect anything to 192's digital cards (instead of enclosure connectors) they will have realtime sample rate conversion which also means they will resolve clock differencies on the fly. This is why some (practical) people have had success and some other (theoretical) people claim that things must be done properly.

Sure, things must be done properly. It just happens to be so that 192 handles things properly FOR YOU and it means you don't have to worry about this. Having an 192 abailable the both are right, it just works.

[Oakdale Post]

Chris, it seems you and I have been chatting on DUC quite frequently!
What is this Soundflower of which you speak?

For all perhaps I should explain my typical workflow on a video based sessions.

1. Set Sync source to Sync I/O referenced to standard definition Black Burst typically at 29.97ndf. (I haven't made the jump to Tri-level Sync required for Hi-Def)

2. Record Voice Over via ISDN. When recording one talent I use either a Musicam Prima 220 or Prima LT. I take the digital output out of either Prima into AES 1-2 to avoid an additional D-A conversion. Each Prima has a sync input so when recording 2 talents simultaneously I use each Primas Sync input and record into AES 1-2 and AES 3-4. To do this without getting digital click and pops because the digital outputs of the Primas are not clocked to each other I use an Aardsync word clock that is referenced to Black Burst and output that into the sync ins of the Primas.

3. Edit VO(s), add music and send full temp mixes and stems to video house so they may do the edit.

4. Receive Quicktime from video house at H.264 and OMF file of any on camera talent used in the project.

5. Begin sweetening. THIS is where the Digital Output of the Mac comes in. As Pro Tools is using the Digidesign Hardware for sound output and I'm using Soundminer to audition and spot SFX I have for years used the analog output of the Mac to audition SFX and Music into inputs 9-10 of 192 #1 set at -10 level.(I have two 192s, #1 with an extra A-D card and #2 with an extra D-A card thus giving 24x24 I/O)

Therefore all I am looking for is better sound quality when AUDITIONING SFX and Music before placing them in the project. Once the right SFX or Music is found, it comes off of another Hard Drive as a bwav file and into Pro Tools.

I know I'm kind of picking nits here, but has always bothered me that I'm using a -10 analog mini plug for listening to anything in a professional environment. The audio is not that bad for audition's sake, so it's not a deal killer. I would just like to have the option of doing it in a more pure fashion.

Make sense?

[ggegan]

I can use the optical input when working on a single Pro Tools system by getting sync from the optical input, but when syncing multiple Pro Tools, I haven't figured out any way of connecting the Mac digitally. If anyone knows a way to do this, I'd love to hear it.