This is the DIY amplifier circuit using transistors 2SC5200 and 2SA1943. This diagram can make 150 watts using 35-0-35 voltage. We can also use other PNP and NPN transistors. like C5198 and A1941. However, this pair can produce a maximum of 100 watts. This diagram is mono.

Crossover for the speaker:
This is a Crossover for the speaker and the tweeter. This crossover saves the speaker and tweeter from the high watts. Without crossover, the horn or tweeter can’t run for a while. Here in this circuit, we can see 2 speakers, one is the bass speaker, and the middle speaker is for mid-range. The inductor size is 1 inch. The copper gauge is 18, and needs 24 turns to make 1mH. 14 turns need to make 0.6mH. Here have 2 pf capacitors. One is 10uf and 250 volts. Another one is 0.47 μF 250V. These capacitors are Non-polarized capacitors.
Details about 2SC5200
2sc5200 Polarity is NPN. The maximum collector power dissipation is 150 Watts. The maximum collector-base Voltage is 250 volts. Max Collector-Emitter Voltage is 250V. The Max Emitter-Base Voltage is 5V. The Maximum Collector Current is 17 amperes.
Details about 2SA1943
2sa1943 Polarity is PNP. Max Collector Power Dissipation is 150 Watts. The maximum collector-base Voltage is 250 volts. Max Collector-Emitter Voltage is 250V. The Max Emitter-Base Voltage is 5V. The Maximum Collector Current is 17 amperes.
The diagram is

Details about C5198
C5198 Polarity is NPN. The maximum collector power dissipation is 100 watts. The maximum collector-base Voltage is 140 volts. Max Collector-Emitter Voltage is 140V. The Max Emitter-Base Voltage is 5V. The Maximum Collector Current is 10 amperes.
Details about A1941
2sa1941 Polarity is PNP. Max Collector Power Dissipation is 100 Watts. The maximum collector-base Voltage is 140 volts. Max Collector-Emitter Voltage is 140V. The Max Emitter-Base Voltage is 5V. The Maximum Collector Current is 10 amperes.
This is the Speaker protection circuit diagram. It can protect our Speaker from the burn. If the amplifier has any problems, this circuit can save our soundbox. Normally, when the transistor makes a short circuit, the voltage comes out from the speaker output line, and this circuit protects that voltage. This circuit should not allow direct voltage to be sent to the speaker. This circuit is essential for protecting the speaker.

This is the Stereo audio amplifier circuit. This circuit can make 30+30 watts using 12 volts. We can also use a 12-volt battery. Stereo audio circuit diagram with bass tone control.
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