Can't set clock source from Mbox 3 to external dbx386

[octoruss]

Hello friends,

I'm hoping you can help me out. I have an external dbx386 mic preamp connected by S/PDIF cable to my Mbox 3. It used to work, but for some reason, I can no longer set the clock source in ProTools to "external" so the dbx can connect.

In the "Hardware Setup" menu, there's a drop down box for INTERNAL and S/PDIF. But nothing happens when I click on S/PDIF.

Does anyone have any suggestions? I think I need to do something in the MBOX control panel, but not sure what....

[mesaone]

Can you set the clock source from within the MBox Control Panel? Click the Setup button on the top right.

[octoruss]

Unfortunately, no. It doesn't permit me to do that either....

[Darryl Ramm]

First Power off the PC and Mbox, Power up both again. PC first. Try again.

I also _think_ that option won't show up unless there is a signal present. Is the dbx box set up to output S/PIDF? Try a different S/PDIF cable. Make sure you are using a 75 ohm/digital coax cable (not any old RCA cable). And make sure that you have the cable going from the preamp out to the S/PDIF in on the Mbox. If that is not it hook up some other S/PDIF source (CD/MP3 player etc.) to the Mbox to test if the problem is the preamp not sending S/PDIF out.

[octoruss]

Thanks Daryl for the reply...unfortunately that didn't work either. Everything was fine, until one day it stopped working. Maybe I did something to the settings I wasn't aware of, but the DBX unit and the cable I know are ok...

[Darryl Ramm]

Originally Posted by octoruss

Thanks Daryl for the reply...unfortunately that didn't work either. Everything was fine, until one day it stopped working. Maybe I did something to the settings I wasn't aware of, but the DBX unit and the cable I know are ok...

So you have checked that by connecting the cable from the dbx to another device with an S/PDIF input and that is received a signal? It's easy to set the dbx output to AES/EBU not S/PDIF and I would no just rely on the dbx front panel LEDs to show things are working OK.

I'd give equal odds of hardware failure in the dbx or Mbox 3 Pro. So as best as you can test the dbx S/PIDF output with another device and test the MBox 3 Pro S/PDIF int with another device (CD or MP3 player).

[Darryl Ramm]

And (not sure this will cause this, but...) make sure nothing on Windows has control of the interface. The MBox 3 is not selected as the system audio device, no other apps are using it etc.

[octoruss]

Damn, I spent another 3 hours playing with this last night. Unfortunately, none of those things work. I don't have another digital device to check the connection, but I don't think it's the hardware.

Reason being, I had this same problem about 6 months ago when I first upgraded to PT11. I couldn't get some things to work, and had Avid do a remote control to tweak my system. At that time I was having the same problem getting the dbx to connect, and AVid did something in the Mbox control panel, I think. But I don't remember what they did to get it working again.

When I click on the "clock source" button in the MBOX Setup control panel, nothing happens. Sooooo frustrated, because I have a great song idea that I can't put down and am afraid I'm going to lose it!

[Darryl Ramm]

I don't have any other bright ideas except just debug as much as you can with what you can. You don't have any other device, like a CD player, DVD player, MP3 Player, computer etc. with S/PDIF out to debug with? I'd take Pro Tools out of the picture, physically unplug the MBox and test it in stand alone mode, maybe just putting it into AD/DA mode in the control panel and seeing if the MBox will decode the S/PDIF input to it's Output 1/2. If not it's really likely a source setup or hardware problem (source, cable or Mbox).

If Avid support fixed it before I'd be calling them back...

[unkJE]

Originally Posted by Darryl Ramm

First Power off the PC and Mbox, Power up both again. PC first.

I always power-up the “other way around”:



Turn Mbox on first. Then turn computer on.