If you are monitoring from the 828 CueMix monitor outs and you can hear sound when you plug a mic into all 10 XLR inputs in turn, then the 8pre->828 ADAT expansion is working correctly, including clocking the 828 from the ADAT clock.

If the monitoring works, you have to turn your attention to why Cubase is not seeing the additional input ports. It could be that your MOTU drivers need to be updated or you should be using a different driver. Are you using the ASIO or the WDM driver?

I'm using the ASIO.

Today I made some progress. I'm trying to get 10 tracks for each microphone on a drumkit. I set it up so each track is picking up a different input. I created 8 new buses for each ADAT preamp on the 8pre, as well as the 2 preamps on my 828MKII. Basically, I set it up so track 1 would be mic preamp 1, track 2 would be preamp 2, etc.

But when I went to record, it seemed like each track was not independent, so when I went through with a single mic one preamp at a time, I discovered this:

Preamp 1 records to tracks 1, 2, and 5.
Preamp 2 records to tracks 1, 2, and 6.
Preamp 3 records to tracks 1, 2, and 7.
Preamp 4 records to tracks 1, 2, and 8.
Preamps 5, 6, 7 and 8 only record to tracks 1 and 2.

I also can't seem to get the 2 preamps on my 828MKII to be recognised either.

I set it up so that there were 10 buses; 8 for ADAT inputs 1-8 on the 8pre, and then 2 for the mic/guitar preamps on the 828. Can anyone tell me what the problem might be? The ultimate goal is to have 10 independent tracks for 10 independent preamps so that each microphone will have its own unique track and editable waveform.