looking for a quality integrated that allows for bypassing of the preamp section

In a simple A/V 2-channel system, I run an Upgrade Co. modded Oppo BDP-83SE directly into my amp, which is currently a Cambridge Audio 840W.  I prefer the extra detail and transparency that going preampless offers but occasionally find the output on some movies too low, even with the volume full up.  I've thought about getting a simple preamp (Parasound zpre) and connecting just for those hard to hear movies but that seems like a real hassle.  Also considering a Creek Destiny integrated that allows for either passive or active preamplication but may need more power than the Destiny offers.  Perhaps the simplest solution would be an integrated that has the inputs that allow one to bypass the preamp and use the integrated solely as an amplifier (what's the term for this input?).  What feature would I be looking for and could I get some recommendations up to $1500 used?  Many thanks.