Guys he's running LaScala's he doesn't need more gain he's already got 65wpc more than he needs. he need a good quality preamp that's not hi gain and that's very quiet.
If you have the funds look at the matching Mac preamps, they are dead quiet even the tube ones and have many features that are quite handy. The volume control will give you a good range of use with your hi efficiency speakers as well.
Also the MC275 is a balanced amp and runs balanced, the single ended input is immediately converted to balanced so your better to run it balanced, one less tube in the circuit. If your running it balanced the first tube closest to the inputs is not critical as its only used in the heater circuit. It's for converting the single ended signal to balanced for the amp.
I have a C2700-MC275 and the paring is excellent. I will say though get the JJ tubes out of the amps/preamps and find something better sounding that's the limiting factor in the new mac tube gear the factory tubes are not the best but they are reliable.