I’ve purchased a couple of monoblocks for my system. Is there a way I can modify/hook up my older B & K ST-140 in mono for my center?
There is no need to modify the amplifier, just use one channel. The amplifier does not care if only one channel is active.
I’ve been trying a different type of biamping-- one stereo amp (PSAudio S300) out wide, and another stereo amp for the “center” (Forte 1A to mini maggies). So you might consider trying a stereo center to see how it sounds. The concept here is having the wide sound stage with a solid center. Check out the Magnepan Tri-Center for further info (they use some pricey Bryston processor, not sure what it does).