Considering going back in time with an old MOTU interface

[digitaldrummer]

you mentioned having it not connected to the id22, so maybe you already tried this... but if not, another way you might be able to check if it's the channel preamp or the ADAT connectivity/clocking, is to disconnect the ASP800 and power it up so that it syncs to it's own internal clock. Then connect the analog out (looks like it has a DB25 so you would need a DB25 to 1/4" TRS snake) and connect that to a different interface (all analog at this point) - if it works ok, then the preamp is OK and it's likely pointing to the ADAT clocking or digital conversion on the ASP800 (or between the two).

Also as others have mentioned, the order in which devices are powered on can make a huge difference in stability. When I had different devices connected via ADAT, that was something I always had to be aware of, and found that if I powered up in a specific order then it was stable 100% of the time (otherwise it was flaky). The interface I currently run has 16 I/O (the UA Apollo) and that was one of the factors that led me to buy it (although I still have to power up and down in a particular order because UAs firewire drivers are flaky too...).

I would suggest 1) power up interface that will be main clocking 2) power up secondary interface (make sure they are locked/sync'd 3) power up computer. And shutdown in the reverse order. Again, this may be old news, but if not, give it a try.

[Artifacts]

Just to report back. Maybe I had two issues. I still have the channel one noise problem. But paying attention to the order that I booted them up (and also the master ADAT settings within the id22 mixer software -- I think I had some saved settings where I was using the ASP800 as the master instead of internal) and making sure I had selected internal for the clocking source, I was able to record some drums (4 tracks on the asp 800 and 2 on the id22) with no issues whatsoever. Of course, I did not use the first channel of the asp800.

This is good news, and I'm stepping away from the cliff and my MOTU time machine.

Thanks for all of the help!