Review on 🎤 Adjustable Electret Microphone Amplifier by Adafruit by Rachel Guzman

Causes capacitive baseline shift effects at high sample rates (40kHz). I'm guessing it's some weird interaction between the output of the amp and the sampling pin. It's like a spike and then an exponential decay for about 6ms, and the spike is about 5 times larger than the signal itself, making it useless for sound perception. Bought 2 to make sure it wasn't just an accident and the second (separate order and production batch) did the same. Other mics like this work just fine.