The main advantages of this solution are the following:
– High power with low voltage.
– Considerable power, even at high load values (Up to 16 Ohm).
With a load of 8 Ohms and a power supply voltage of ± 25V, the maximum performance that can be obtained is 150 W per channel. While with 16 Ohms load, and a power supply voltage of ± 35V, we will have a maximum of 170 W per channel.

This 300W RMS stereo power amplifier require symmetrical power supply to work, the circuit diagram is included in this post.

300W RMS Stereo Power Amplifier Schematic Design

300W RMS Stereo Power Amplifier Part List

SEMI-CONDUCTORS
4 TDA 7294

RESISTORS
56K Ohms (green, blue, orange) : 8
8K2 Ohms (gray, red, red) : 3
5K1  Ohms (green, brown, red) : 14
8.2 Ohms 1W (gray, red, gold) : 4
2.7 Ohms 1W (red, purple, gold) : 4
22K Ohms (red, red, orange) : 2
1K Ohms (brown, black, red) : 4

CAPACITORS
4700 uF / 35v electrolytic capacitor : 2
22 uF / 35v electrolytic capacitor : 12
1 uF / 35v electrolytic capacitor : 4
0.1 uF / 250v polyester capacitor : 4
0.1 uF / 100v polyester capacitor : 4
0.47 uF / 100v polyester capacitor : 4
10 pF / ceramic capacitor : 4
390 pF / ceramic capacitor: 2

MISCELLANEOUS
25-amp diode bridge : 1
Diodes 1N4148 : 2
fuse holders for printed and 6 amp fuse : 4
small 3-pin connectors : 2
large 3-pin connectors : 2
small 6-pin connector : 1
18x18v to 12 Amp transformer : 1
Square mica insulation. : 4
coils of 10 coils with air core : 4
Of 1/4 inch and wire 18.

The resistance of the 12v cooler is calculated:
(15 / milliamperes of fan) = x Ohms.

300W RMS Stereo Power Amplifier PCB Layout Design

Power Supply for 300W RMS Stereo Power Amplifier

This is the scheme diagram of 20 Watt stereo audio amplifier which use dual IC TDA2005, one IC for left channel and the another one for right channel. Each IC will give you 20 watt output, so the output will be 2×20 Watt. The supply voltage for this circuit is 8VDC to 18VDC, use regulated power supply for better audio output performance.

Use a good quality transformer (of course it wiil be more expensive) to get less noise. It will be another good way to use a sufficient battery to power the circuit. Keep the supply wires as short as possible. Input source should be isolated from the external noises too. It is recommended to use coaxial cable to connect the input audio.

Bottom PCB Layout:

Top PCB Layout and Component Placement:

20 Watt Stereo Audio Amplifier Technical Data:

• Performance of TDA2005M: (for this circuit); At 14.4 V supply voltage: 2 x 20 watts (stereo) into 4 Ohms.
• Distortion: Approx. 0.2% at 4 Watts into 4 ohm load.
• Frequency Range: Approx. 20 Hz to 22 KHz.
• Input Sensitivity: Approx. maximum 150 mV rms.
• Power supply: + 8 to 18 volts, approx. maximum 3.5 Amps per channel.