Amplifiers

Most of the amplifiers here are class-D speaker drivers — some take I2S digital audio directly, others take an analog signal in. A few (the MAX9744, the TPA2012) go loud enough to fill a room.

MAX98357A and MAX98357 I2S class-D amps, PAM8403 and TPA2012 analog stereo amps, MAX9744 20W stereo amp, LM386 and PAM8302 mono amps, and discrete op-amp packs for signal-level work.

• Adafruit's MAX98357A breakout takes I2S digital audio straight from an ESP32 or Raspberry Pi and drives a 3 W mono speaker with no separate DAC stage; DFRobot's MAX98357 I2S Amplifier Module is the same idea at 2.5 W.
• PAM8403 and TPA2012 boards are analog-in stereo class-D at 3 W and 2.1 W; Adafruit's Stereo 2.8 W amp adds I2C gain control and AGC to keep audio from clipping.
• The MAX9744 stereo 20 W class-D amp handles larger speakers; the LM386-based Gravity module and PAM8302 mono amp cover simpler single-channel builds where a full I2S pipeline is more than the project needs.
• For signal-level work, Adafruit's dual rail-to-rail op amp (2.7–6 V supply) and Pimoroni's op-amp packs are the discrete building blocks; the STEMMA Speaker bundles a class-D amp with a 1 W 8-ohm speaker for plug-and-play output.