Audio Power Amplifier with TDA2050

This project is an audio amplifier based on TDA2050 and LM1875.


This is not an ordinary project, but an attempt to make a PCB that is suitable for TDA2050 andLM1875 and has all the necessary circuitry on board – power supply, speaker protection, delayed turn-on and fast turn-off. This is achieved using the convenient uPC1237 IC.

TDA2050 and LM1875 are pin to pin compatible, the differences in their schematics are the values of a couple resistors and one capacitor. All this allows to make an universal circuit board, suitable for any of these two ICs.

It is 2x30W, but it depend of the power supply voltage and the impedance of the speakers connected to the output.


Parts List

C1 100nF C050-024X044 
C2 100nF C050-024X044 
C3 1000uF E5-10,5 
C4 1000uF E5-10,5 
C6 2.2uF C050-075X075 
C7 220nF C050-030X075 
C8 22uF E3,5-8 
C9 100nF C050-024X044 
C10 100nF C050-024X044 
C11 1000uF E5-10,5 
C12 1000uF E5-10,5 
C13 4.7uF E2,5-6 
C14 2.2uF C050-075X075 
C15 220nF C050-030X075 
C16 22uF E3,5-8 
C17 4700uF E7,5-18 
C18 4700uF E7,5-18 
C19 47uF E2,5-7 
C20 22uF E3,5-8 
C21 22nF C050-025X075 
D5 1N4148 DO35-7 
D6 1N4004 DO41-10 
D7 BZX85C12V DO41Z10 
IC1 LM1875 T05D 
IC2 LM1875 T05D 
IC3 UPC1237 SOP8 
IN 6410-02 
IN1 6410-02 
J1 OUT1 AC2 
J2 OUT2 AC2 
J3 AC AC3 
JP1 JP1 
K1 G2R2 G2R2 
LED 6410-02 
LED3 6410-02 
R1 1k 0207/2V 
R2 20k 0207/12 
R3 22k 0207/7 
R4 1M 0207/7 
R5 1R 0414V 
R6 1k 0207/2V 
R7 20k 0207/12 
R8 22k 0207/7 
R9 1M 0207/7 
R10 1R 0414V 
R11 2k2 0207/7 
R12 120k 0207/7 
R13 120k 0207/10 
R14 56k 0207/7 
R15 9k1 0207/7 
R16 10k 0207/7 
R17 92k 0207/10 
R18 330R 0207/10 
R19 68k 0207/7 
R20 3k9 0207/10 
R21 10k 0207/7 





  • Audioguru

    The TDA2050 is not available at both of the largest electronics parts distributors in North America. Is it obsolete?

    4 years ago
    • availlyrics

      Its available in India (even TDA2030 for 0.25$), but can’t say same whether they are fake or not. I’m currently using TDA2030. If you need any help email me – availlyrics at the rate rediffmail dot com

      4 years ago
  • Setya-tech

    Bridge transformator less??

    1 year ago
    • admin

      Bridge rectifier B1 is rated at 8A and we recommend using same rating for this project.

      12 months ago
  • Anirvan

    How much supply voltage can be given to a cheap tda2050 or tda2030A ?

    5 days ago
    • TDA2050 can accept a maximum absolute supply voltage o +/-25V and TDA2030A +/-22V

      5 days ago

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