Chiro C800, how do you work Zone 2?

I have an old Chiro c800 preamp and can't seem to find the manual. I press the zone button on the front panel and can switch which source goes to zone 2, but I can't seem to figure out how to change the volume for that zone. I've never used that feature, but would like to do so now. And, I can't find an online manual either.

If anybody knows the answer, I'd appreciate it.
Rich, perhaps we can help each other out. I too having
problems setting up C800......VERY complicated. How does
one even determine if unit fully functional in the first
place. Anyway, I have copy full manual. I would be more
than happy to share with you if you could help me set up
my C800. Please contact me if you are interested. Thanks,
Can u email a copy to me too? I also face the same problem. Thanks, Alan
hi i could help you set up and i also need the manual please if u could email a copy of the chiro c 800 manual ill help you