With Cubase and the Garritan Personal Orchestra I want to record training mp3s for my choir. My idea is to have one instrument on the left channel, all others on the right channel. So in the aria player mixer I put one pan knob far to the left, all others far right. But whatever I do, on the left channel I hear the other instruments, too (yes, not that  loud, but I hear them). All insert effects are turned off.

What is the mistake I make?

Regards, Christoph