parang ganito po?

your midband gain is ~30000/3300 or ~ 9.1 say 10.....
for an output of 14 watts into 4 ohms, output voltage is 7.5v rms....
now your 24 volt rail gives you 12volt peak(assumes no voltage lost in the output trannies) or 8volts rms...
thus we can see that with the rail voltage as shown, it will not be possible to get 14 watts output...
another thing to consider is the voltage drop on the rail once big current is drawn from the supply...
therefore looking at the schematics alone does not give you the whole story....
we have to consider the completed amps with its power supply to find out exactly what the power output will be...