D/A converter looses sync from Mbox 2

[Silvermannen]

Hi,

- (new)Mac Book Pro Intel DP2.8, 4GB RAM
- Mac OS 10.5.5 including latest "USB" Firmware update from Apple
- Mbox 2 (Tested both firmware 1.38 and 1.43)
- Pro Tools 7.4.2
- Mytek Stereo96 DAC (via SPDIF output of Mbox 2 to Mytek SPDIF input).

ProTools is working flawlessly all the time.
But the external Mytek Stereo96 DAC looses sync from the Mbox2s SPDIF out.
Tend to think that the Mbox 2 does not get the proper amount of current from the MBP to produce a decent SPDIF signal out.
Despite the Mbox 2 connects directly to (either) of the external USB buses on the MBP.

Sometimes the combination works for 11 hours in a row or sometimes just for 30 seconds.

Sometimes it syncs back by it self OR sometimes it takes 10 minutes of total shutdown before it works.

In the Mac control panels the Mbox 2 is always connected and the analogue outputs on the Mbox 2 is working all the time.

Just the SPDIF connection that malfunctions.


All help appreciated,

Daniel

[albee1952]

2 things I would look at. 1-are you using the USB port that is farthest away from the screen(i.e. closest to you)? It makes a difference. 2-are you using a real SPDIF cable, or just whatever RCA-RCA cable was handy? RCA audio cables are not spec'd for digital so while they may work "okay", they may not be up to the task at hand.

[Silvermannen]

Hi albee1952,

Thanks for your reply.

I have tried both USB ports, I have not been able to trace any difference.
I know that other models of the MBP have been said to have that particular issue.

Have you hear anything about the latest (2008) MBP to have the same issues?

I will get some further cables to day.

Thanks,

Daniel

[Silvermannen]

Followup day #1

After getting the most expensive SPDIF cable, a 12 hour day has passed without any problems at all.

So thanks for your advices albee1952.

Regards,

Daniel