This is an audio amplifier circuit using integrated LM1875 stereo to 2 x 20 Watts. With power supply for ease of assembly for any hobbyist. With a power of up to 20 Watts stereo amplifier that is suitable for use as power audio amplifier in various applications such as power amplifier for PC audio, FM radio, MP3 speaker, finally you’re sure to find great uses for this amplifier with LM1875 easy to assemble.
Diagram of stereo power amplifier lm1875
Suggested printed circuit board for mounting the amplifier chip LM 1875
Part List for assembly of a stereo amplifier with LM1875
| Parts | Value |
| Capacitors | |
| C1 | 100nF/63 V Polyester film or ceramic capacitor |
| C2, C3 | 3300µF/35V Polarized electrolytic capacitor |
| C4, C5, C12, C13 | 2.2µF/25V Polarized electrolytic capacitor |
| C6, C9 | 220nF/63V Polarized electrolytic capacitor |
| C7, C14 | 10µF/25V Polarized electrolytic capacitor |
| C8, C11 | 2200µF/35V Polarized electrolytic capacitor |
| Semiconductors | |
| D1, D2, D3, D4 | 1N4004 |
| B1 | KBL406 4A Bridge Rectifier or equivalent |
| LED | Red LED 5mm |
| IC1, IC2 | LM1875T |
| Connectors | |
| IN-L | Connector Left channel audio input |
| IN-R | Connector Right channel audio input |
| OUT-L | Connector Left Channel Audio Output |
| AC | Connector to the transformer |
| OUT-R | Connector Right channel audio Output |
| Resistors 1/4 watt 5% | |
| R1, R6, R12 | 10k Brown, Black, Orange, Gold |
| R2, R3, R4, R8, R9, R10 | 22k Red, Red, Orange, Gold |
| R5, R11 | 220K Red, Red, Yellow, Gold |
| R7, R13 | 1R Brown, Black, Gold, Gold |
| Several | |
| J1 – Jumper – piece of wire | |
| Heat sink for the IC, printed circuit board, solder, Box to the amplifier, speakers, 30 watts 4 ohms | |
| Transformer – 12 to 18 VAC / 2A to 3A | |
Download PDF Files Mounting amp with LM1875
Download PDF Mirror
This schematic is incorrect. R5 and R11 should go from pin 4 to pin 2 of their respective ICs, not the junction of the 10k resistor and the 2.2uf capacitor. Also, much better performance can be achieved using a centre-tapped transformer and dual-ended supply. See the datasheet’s typical application schematic.
hi i have problem i don’t have any voice and should i put capacitor c10 or not?
There is an error r5 and r11 220k must connect straight to pin 2 off ic1 and ic2.
hello hi do you have WhatsApp or something else to help me thanks a lot
after making this circuit when i give power,there is a bang voice,what is the reason..plz guide
sir
i need help regarding soldering diode whichis with right side of 1R resitor,should it be sold with +ve
please print circuit pdf file. thank you!
Trafo 12 V ct or 12V simetris please,
12v dc amplifier stereo audio top hi fi power sistem please sir my numbers 09417825411, 09417812056 please back call me
Why my left out make noisy sound, but the right one dont issue anything. That problem can be related with suuply?
Help !!!!!!!!!!
Hey …..
Very good,that’s like a professional project.Easy to make,assemble,looking beautiful….
Thanks…..