Power Amplifier Speaker Protection Circuit Schematic

Power Amplifier Speaker Protection Circuit Diagram

Power Amplifier Speaker Protection Circuit Schematic

While switching a power amplifier on, a loud thump sound is heard to sudden heavy discharge current through the speaker at the time of power on. This current may damage the speaker, especially in case of direct coupled amplifier.

Speaker Protection Circuit Schematic

R1 5KΩ Preset
C1 1000µF 25V
C2 0.1µF (104)
D1 IN4001
Q1 BC107
RL1 9V 500Ω Relay
LS1 Speaker

The circuit given here protects speakers from the current surge. When the amplifier is off, relay switch is also off. When the amplifier is switch on, R1 and Ci provide delay of a few seconds to switch the transistor on which energizes the relay.



Delay time is proportional to value of R1.

Power Amplifier Speaker Protection circuit Speaker Protection Circuit Diagram

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18 comments on “Power Amplifier Speaker Protection Circuit Schematic
  1. Hotwaterwizard says:

    Nice circuit. I would love it if it could use a 12v Cube relay instead of the 9v relay

  2. pasanlaksiri says:

    Hmm hey, you better at least use 555 timer for this instead of capacitor.

  3. sandra akoth says:

    please send me a 50w power amplifier design driven by a pre amplifier

  4. Yoram says:

    Capacitor use is just fine do not listen to Pasanlaksiris advice!

  5. Nkwenti says:

    I use C945 transistor for this schematic and it works well….thanks for the diagram sir

  6. GreenDiamond says:

    I am an idiot so I would rather not risk my speakers by making one myself so I am wondering where I can buy factory made units on line?!

  7. muththu says:

    very nice jobs

  8. mostafa says:

    plz i want a full picture i want to put all the components above on the board plz

  9. Madhavi says:

    This is interesting and useful circuit. Would try to build this by myself. Thanks

  10. AudioAmps says:

    This weel not protect speakers from dc , only 5sec on start.but nice circuit i build one, only puted BC548 and dual contact realy for stereo is work perfect! 🙂

  11. djbluegee says:

    i need help about relay, it not protect speakers from dc

  12. okudzeto osei says:

    good job sir

  13. okudzeto osei says:

    can someone me help here…what are the things you need to consider when parallel output drives(transistors) of an amplifier…views are warmly welcome thanks.

  14. Sv says:

    Can someone please provide a working multisim file for this

  15. joseph says:

    pls I want a full picture and the Components

  16. chayapol says:

    It is so easy circuit no “Tump!” on speaker start.

  17. Gyampoh says:

    Good Job this is universal, the applications are many.
    Keep up with your work.

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