You must like the sound of woofers bottoming out.I've enough good sounding amps , I need power to juice the four 12'' woofers .
I already have the Thel Audio Accusound 100 bud I need a second one that can perform the same . See the pic of the Accusound
Btw, your idea of adding one extra output mosfet would not work. Because you lowered the supply voltage. See, original first post calls for +/_80 volts. You asked if you get more power with one extra output, but with +/_75 volts.
That's why i suggested to get behringer or lab gruppen. Perhaps classD would be for you. Perhaps start new thread, ask question. I used 2000 watts behringer for our company amateur music group. Used to be soundman, just for fun.
(50^2)/8 = 312, depending on the weight of your ptx, could be lower..How much power ( Watts ) would this version have with 75 Vdc rail voltage by 8 Ohm ?