I'm using a MOTU 828 Mkiii firewired into an Acer laptop, with a MOTU 8Pre as Optical A in and a Fostex VC-8 (essentially an ADAT AD/DA i/o section) into Optical B. Recording with Nuendo 4 in WinXP Pro. Getting good results except for this:
The SECOND Optical I plug in gives me very minute rhythmic clicks (actually, more like small white noise bursts), about 300ms apart, on all inputs. E.g., if the 8Pre is enabled first, the Fostex has the clicks. Plug in the Fostex first, the 8Pre has the clicks. (I can switch the clicks by powering each off and back on, in the correct order.)
If I change the buffer size, the clicks then default to the Optical B and stay there. Not sure what that signifies, but I'm mentioning it in case it is a clue as to the glitch. (I also swapped out an actual ADAT for the Fostex, and it behaves in the same way.)
This happens at 48k/24, 44K/24, 48k/16 or 44k/16. I've tried clocking the Fostex with both Optical and Word clock, no difference.
The clicks are very low, maybe -56 db, but they are very high frequency, and they do show up on the tracks.
Once again:
- Windows XP Pro
Nuendo 4
MOTU 828 Mkiii, FW interface
MOTU 8Pre
Fostex VC-8
Acer laptop, 1.9 Dual core, 2Gig RAM