Skip to content

Adafruit I2S Amplifier BFF Add-On for QT Py and Xiao

12 units available with a short lead time.

Express post shipping available (product has a short lead time)

The Adafruit I2S Amplifier BFF is a compact add-on that brings high-quality 3W audio to any QT Py or Xiao development board. Featuring a MAX98357 Class D amplifier, it delivers crisp I2S digital audio using just three GPIO pins (A0, A1, A2) that don't conflict with I2C, UART, or SPI.

Designed as a "Best Friend Forever" board, the BFF mounts directly onto the back of your QT Py or Xiao — solder it permanently or use pin and socket headers for a removable setup. Connect a 4Ω or 8Ω speaker via the onboard picoblade-compatible connector and you're ready to play audio.

Key Features

  • MAX98357 3W Amplifier – Class D I2S amplifier pre-configured for stereo mix output at 9 dB gain
  • BFF Form Factor – Mounts directly onto the back of any QT Py or Xiao board
  • Picoblade Speaker Connector – Easy plug-in connection for 4Ω or 8Ω speakers
  • 3-Pin I2S Interface – Uses A0 (data), A1 (word select), A2 (bit clock) — no conflict with I2C/UART/SPI
  • Wide Chipset Compatibility – Works with ESP32, nRF52840, and RP2040-based QT Py and Xiao boards
  • Solderless or Permanent – Use headers for a removable connection or solder in place

Ideal For

  • Compact audio playback projects with QT Py or Xiao
  • Portable sound devices and notification systems
  • IoT projects requiring audio feedback
  • Space-constrained builds needing amplified speaker output

Package Contents

  • 1× Adafruit I2S Amplifier BFF PCB (assembled and tested)
  • 1× Header for soldering to QT Py
Compatibility Note: This BFF does not work with the original ATSAMD21 QT Py, as its A0–A2 pins are not I2S capable. We recommend the QT Py RP2040 or any ESP32-based QT Py instead.
Note: Speaker and QT Py board are not included.

Resources

The Adafruit I2S Amplifier BFF Add-On for QT Py and Xiao appears in the following collections:

SKU AF-5770