Hi Jed,
Thanks for your message.
Congratulations to the Yamaha THR II amp, which seems to be a great choice.
Please have a look at the routing example in our Getting started with Cubasis tutorial, to learn how to connect your THR II amp with Cubasis and select the available channels for recording.
In case, you use Cubasis LE, please note that the available inputs/outputs are limited to 2/stereo.
Hope that helps.
Best wishes,
Lars