I wanted to know the power O/T of a push pull amp, by ohm's law, I calculated the full swing of the amplier in to 4 ohms, like this.

I=E/R so I = 55volts/4ohms thus I=13.75amps

P=E*I so P = 55volts * 13.75amps thus P=756.25 watts

but first of all, that seems like a lot of power for 55 volt rails

next, a person told me another formula for this which is

vcc^/4/2 where you have supply(55) squared divided by the speaker imp divided by two, which gave me 378 watts for the same amp!

Can anyone tell me whats going on here and confirm the proper way to calculate power output??