I've set up a ESP8266 to play MP3 radio from a web server, using the ESP8266 Audio library. My circuitry is pretty much like this:
enter image description here

My question is, how can I amplify the volume of the sound, as it is not high enough for me. Is it merely connecting higher voltage to the circuitry, like a 9V battery? If so, how can I know the limits my speaker and my transistor can handle? Is there a max voltage specified for speakers and transistors? Are there ready-made amplifiers for such things?

I would appreciate if someone could tell me exactly what kind of products I need in order to amplify the ESP8266. I prefer plugging to the electricity rather than using a battery.

Thanks !

  • \$\begingroup\$ The output of an audio amplifier is AC. Your darlington transistor produces variable DC that will fry your speaker. The transistors in an audio amplifier are biased. Your transistor is not biased so it will produce extreme distortion and will not be loud. An audio amplifier IC like an LM386 in a circuit shown in its datasheet produces only 0.22W (which is a low level) into an 8 ohm speaker with your 6V supply. An LM1875 amplifier with a 50V supply produces 22W (which is a loud level) into an 8 ohm speaker. \$\endgroup\$
    – Audioguru
    May 6, 2021 at 0:11
  • \$\begingroup\$ Your speaker appears to be tiny and has no enclosure so it will sound vert tinny and produce only high frequency sounds. \$\endgroup\$
    – Audioguru
    May 6, 2021 at 0:13
  • \$\begingroup\$ @Audioguru: The ESP8266 doesn't have an analog output. The library is providing on/off pulses to drive the output. A single transistor is all it takes. I'm not saying it'll sound good, but it doesn't require a regular amplifier. \$\endgroup\$
    – JRE
    May 6, 2021 at 8:49
  • \$\begingroup\$ @Audioguru - So you're saying that all I need is just higher voltage? \$\endgroup\$
    – YoavKlein
    May 6, 2021 at 8:51
  • \$\begingroup\$ PN2222 NPN Transistor \$\endgroup\$
    – YoavKlein
    May 6, 2021 at 9:14


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