This the circuit diagram of 260W power audio amplifier capable of delivering up to 260W RMS at 8 Ohms load. The signal level of 1 VPP standard amplitude is input to a differential stage composed of BC556C Transistor. Then the signal is input to the post-formed by complementary transistors in order to achieve the desired power.
All transistors except BC556C, should be mounted on a suitable heatsink to prevent overheating. It would also be ideal to mount the plate in a metal cabinet to prevent unwanted noise.
This power amplifier uses complementary transistors in order to achieve the desired power. It is powered by a dual polarity power supply of +/- 45V and consumes 4 amperes, the circuit diagram provided. ALL diodes labeled A, B and C in the amplifier scheme diagram are 1N4001 and also be mounted on the heat sink but with silicone grease. The entry should be 1 Volt to deliver full power.
The power supply can not be regulated, but the filter must be very good to avoid “hum” in the speakers.
In this case the transformer has a secondary with midpoint of 32V / 0V / 32V (center tap). For mono configuration must have a current of 4A, 8A stereo. The diodes must be at least 100V by 6A (mono) to 12A 100V (stereo), you may use bridge amplifier for the rectifier diode. The capacitor should be minimum of 4700μF x 63V each.
Well, I tested it (only at +/-30VDC) and got an output power of around 60W peak. That was using TIP3055/TIP2955 as ouput devices instead of the Darlington ones. Having said that, Darlington transistors would not constitute higher power, rather higher current handling capabilities. So, I’m not sure how you calculated it’s output power, but I’m assuming you did P=V*I, so you took the output p-p swing and multiplied it by it’s current draw. This would be incorrect. The calculation is P=(Vpeak^2)/R, so half the p-p voltage squared divided by the output load. Secondly, I have no idea why you have a 10R/5W resistor in series with the output before the speaker, without an inductor coil. This serves no purpose except introducing distortion, unless you were attempting to use it for short-circuit protection. Finally, I also have no idea why you’re using a 5W 10R resistor in the Zobel network, a 1W devices will be sufficient. That aside, the frequency response is good and produces a nice power of 50W (not 260W) which is clean.