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A really small and cheap audio stereo amplifier 3w/3w from 5V psu

shumifan50

Jan 16, 2014
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I found this cheap and cheerful amplifier based on PAM8403 chip. It gives 2 channels of audio, is a D-class amplifier(no heatsinks needed). Several breakout boards are available. The chip requires the absolute minimum external components which are included on most of the breakout boards. The breakout boards can be driven directly from a DAC output and can be directly connected to speakers. The chip supports a a shutdown and mute pin although not all breakout boards make these available. Overall it is perfect for battery driven projects and needs 2-5.5v power. I provide no link, just search for "pam8403 breakout".
The D-class amplifiers have efficiency of more than 90% which makes the pam8403 a much better choice than the lm386, which I used in the past.
 

crutschow

May 7, 2021
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That will only do 3W with a 5V supply if you are using a 4Ω speaker.
 

dave9

Mar 5, 2017
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For what application, general purpose music listening?

I'd think a better target for a class D battery powered amp is 12V, powered by a cordless tool battery or 3 x 18650. What battery arrangement is a good match for 5V, max 5.5V anyway?

PAM8403, even within the use of a 4ohm speaker to get 3W, that's at 10% THD. Why build something that's always leaving you wanting more? Then again it comes back to the application, a watt or two would be enough for some purposes.
 

shumifan50

Jan 16, 2014
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This suggestion was not for high fidelity or filling a room with music. It is intended for portable devices, most likely using earphones. The PAM8610 is more powerful, but more output = more power hungry. At 5V this is easily driven with most micro controllers. If you need more then go a different route. I use these for gate doorbell and gate intercom. It is small (VERY small) with convenient power requirements and sound quality is not that important as the DAC that I drive it with can only do 8KHz.
I just thought I would share for those with requirements for such an application.
 

shumifan50

Jan 16, 2014
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This thread really belongs in the micro controller section as this is a board typically used in micro controller applications and not really an audio device - merely a device enabling easy audio output from a micro controller like the ESP32/ESP32-S2.
Useful for limited audio quality like robotics etc ( 8 bit DAC/8KHz sample rate).
 

Audioguru

Sep 24, 2016
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When the supply is 5V, the PAM8403 produces 3W per channel into 4 ohms with horrible 10% distortion, 2.5W per channel with less distortion and only 2W per channel when clipping begins.
The PAM8610 datasheet says "Not Recommended", Use PAM8006A".
 

shumifan50

Jan 16, 2014
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I reiterate that this is not an audiofile amplifier, but it provides an easy solution to add sound to a MICROCONTROLLER, which is what I use it for. It is ample for implementing an intercom - we lived with 3 khz on telephones for decades, so driving this amp with the 8 bit dac at 8khz on the esp32 will provide acceptable, to most, performance. I stress again that this belongs in the microcontroller section.
 

Audioguru

Sep 24, 2016
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I remember hearing 8 bits audio many years ago. It sounded awful.
 
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