Here's my set up
On the Yamaha CVP 96
The regular audio out goes to the input of the TubeAmp, and that output goes to an input on the back of the Firestudio so I can play the piano, as a piano, through Logic.
Then, the midi output of the Yamaha is plugged into the midi input of the Firestudio so I can play the Yamaha as a midi input.
I had it working once, and when I played/recorded, it sounded like a bass. But now it just sounds like a piano and it is not very inspiring during the record process. I can get it to record midi events, but it only sounds like a bass when I play it back.