After reading Tls49's response, I think I may have missed something.
"Swapping the monoblocks left to right the louder sound swapped too. The left channel is now lower in volume."
Did you actually swap the amps so that the IC's going from the preamp to amp remained connected to the same channel, or did you just swap the IC's? If its the former, then Tls49 is right. Disregard everything in my 1st post except the part about the Balanced/SE switches.
"Swapping the monoblocks left to right the louder sound swapped too. The left channel is now lower in volume."
Did you actually swap the amps so that the IC's going from the preamp to amp remained connected to the same channel, or did you just swap the IC's? If its the former, then Tls49 is right. Disregard everything in my 1st post except the part about the Balanced/SE switches.