The components for the second two Space Rocks needed to take up less space. In the case of Undarum, the amplifier was too large. Shown here is the circuit on a new PCB (version 3) using an Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302), which has a much smaller footprint and height than the previous self-assembly amplifier kit I was using.
Testing the speaker inside a (one-half) Jesmonite Space Rock.
Love the packaging for this. One of these.
It’s definitely louder than the previous one, and with a better frequency response, but I think I will still need a pre-amp.