Mac built-in digital input

[rainsong]

Curious if anyone who's upgraded to PT9 has tried using the built-in digital input on their Mac (Mac Pro, specifically) to record via outboard converters.

If so...is it stable? And how low of buffer settings are you able to use?

Seems in theory like this would be better than using a USB or FW interface, if you're only tracking two channels at a time...but somehow it also feels to good to be true.

[getz76]

I played around with it last night. I had it working with two inputs in from my RME ADI-2 via optical SPDIF to my Macbook Pro. It was working fine, but I did not have the time to really test it out.

[getz76]

Spent a couple of hours with headphones. Everything is working well. Very lovely.

Hardware Buffer Size is at 64 samples.

Looks like my light mobile rig just lost the Mbox 2. My 2U rackbag with the RME ADI-2 and the pair of Summit Audio 2BA-221's just pairs with my Macbook Pro. Dead simple. I am going to do a stereo recording this weekend to see how the system holds up.

This is very cool. Not that the MBox 2 was heavy, but one thing less to carry is nice. And more often than not, the issue was table space. Now I can literally just put the Macbook on top of the rack bag. If I can get a mic-stand at the location, I can carry my entire rig in my backpack (Macbook, cords, charger, and say a pair of Crown CM-700s with mounts) and my rack bag to do a stereo recording of a live show or rehearsal. Very, very cool.

The only issue I can identify is clocking. I cannot get the Pro Tools Aggregator to use the ADI-2 as the clock source. Instead I am stuck using the Macbook's as the clock source. Not a big deal, but I should be able to choose. Maybe I'm missing something.

[gearhead2010]

I've done extensive testing with my MacPro and Rosetta 200 and found that you can not have the Mac lock to an external clock even if you have a digital port selected in the Audio MIDI setup set to "Make master clock" etc.

Here's the simple test to prove it:

In PT 9 make a mono aux track and insert a signal generator plug-in on it.

Listen to the track - hear the clicks and pops and little skips? That's bad clock.

Set the clock back to internal and have the external AD/DA set to external clock and it goes away.

This all has to do with the MacPro being unable to clock externally.

I used to have no problems clocking my old G5, as it would let you choose external in the Sound Preferences panel, but not anymore with the MacPro.

It's a real shame too, it performed pretty well using core audio and the built-in sound chips.

gH

[getz76]

Thanks for the info. That is exactly what I am experiencing, so I believe you.

[rainsong]

That's a shame. Not the end of the world, I guess, but I was hoping to clock my Mac Pro to my API A2D and have that be that.

Thanks for the the followup.

[ScottRobinson]

Originally Posted by gearhead2010

I've done extensive testing with my MacPro and Rosetta 200 and found that you can not have the Mac lock to an external clock even if you have a digital port selected in the Audio MIDI setup set to "Make master clock" etc.

Here's the simple test to prove it:

In PT 9 make a mono aux track and insert a signal generator plug-in on it.

Listen to the track - hear the clicks and pops and little skips? That's bad clock.

Set the clock back to internal and have the external AD/DA set to external clock and it goes away.

This all has to do with the MacPro being unable to clock externally.

I used to have no problems clocking my old G5, as it would let you choose external in the Sound Preferences panel, but not anymore with the MacPro.

It's a real shame too, it performed pretty well using core audio and the built-in sound chips.

gH

If this is the case, how do I clock my AD to the macbook clock?

I am using a Lucid 24/48. I want to use my headphone output and digital input to record a mic or two. Can't set the macbook to clock off the Lucid, and don't have a way to run clock signal from the macbook to the Lucid.

Location recording tonight.. help would be appreciated!

[John_Toolbox]

I also have tested this and came to the same conclusion, the mac needs to be the master.

[ScottRobinson]

Originally Posted by John_Toolbox

I also have tested this and came to the same conclusion, the mac needs to be the master.

Yep.. I have also come to that conclusion. So any thoughts as to how I can clock my AD to the macbook?

[ScottRobinson]

On a side note, I've been monitoring it for about 30 minutes and haven't caught a single click or pop or glitch... still worried though.