I know somebody who has placed his OPT's behind the speakers and has connected them to his EL34pp amp with long wires. That was not my plan, I am not desperate. But what is better, placing amps next to the loudspeakers and a long connection to a preamp, or simply long speakercables to the amps?
It’s easier for the amp to drive distant speakers than it is for the preamp to drive a distant amp due to many factors.