This one is the most recomended Thimios
Power:
80 watts RMS at 8 ohms.... total harmonic distortion 0.002%
150 watts RMS at 4 ohms... total harmonic distortion 0.003%
250 watts RMS at 2 ohms... total harmonic distortion 0.004%
300 watts RMS at 2 ohms... total harmoni distortion 10%
Supply voltage is 42 volts and cannot be 43 and cannot be more than that because BD139 transistors will melt....so...maximum voltage is 42..and this is the supply voltage.
Power needed is 150/300 and 550 watts to 8/4 and 2 ohms
regards,
Carlos