Alesis Andromeda A6

hey, I have a problem with mix mode, when in mix mode my 1st program 
in mix mode gets to be really distorted, sounds like a chip is 
busted or something.  what's up with that? it sound so bad in mix 
mode.  I just picked this up, i hope it's not broken.

Also, how can i assign a full keyboard utilizing multiple progs in 
multimode?  is it just turn off external and then cincrease the 
range?  

I don't have a manual, so this is being a REALLY big pain in the ass 
to me.  giving me such a headache:(...