Can I mix different yet similar amps...

Hello to all...

I am using a Parasound HCA 750A (in stereo mode) which can be used with or without a preamp. I'd like to use it in mono (for one channel) but am having a hard time finding another 750A ( without rack handles) for the other channel. Could I use a Parasound HCA-1000A instead for the other mono channel, or must they match?
It really probably is best they match.

Unless you passive bi-amp, and use the 750 for the top end, 1000 for the bass.
The transfer function on the amps must match if you care about time and phase, otherwise welcome to Baskin Robbins where there are no wrong answers.. pick flavors you like