Can I use a multichannel amp to bi-amp my speakers

A multichannel amp will only work to bi-amp if each 'amp section' has it's own input, which (as noted) requires an active xover.  In my case, I've dispensed with a pre-amp, gone to active eq, and use a matrix (actually a pair) to control inputs and how various elements interconnect.

I really don't miss a stand-alone pre-amp, BTW...