#356 PX088A Audio Effects Chip

Figuring out how to use the PX088A “Für Elise” music chip.

Build

Here’s a quick demo…

Notes

The PX088A potted music chip is usually listed as something like “Alice Music Voice Module Tone Loop Control IC Chip Board for DIY/Toy 3V-4.5V”.

Turns out it plays the main theme from Beethoven’s Für Elise.

PX088A_chip

Usage and Schematic

This is one of the simpler chips to control, as it only has a single effect. But as with all these potted music chips, information is scarce and ofter wrong or misleading!

There are 5 connectors:

VCC: some sources indicate a working voltage of 3 to 4.5V. It actually works down to 1V (although volume suffers)
“T”: apparently a tone switch?
C: transistor collector and signal out
B: transistor base
E/GND: transistor emitter/ground

The documentation I have found (listed on some sellers’ aliexpress pages) indicates the music chip should be used with:

3-4.5V battery
a small signal NPN transistor e.g. S8050
a speaker or buzzer of some description

The picture below shows 3 (of many possible) configurations:

A: the “recommended” configuration. I found this to be totally unsuitable for an 8Ω speaker: it presents a very low resistance to the battery and draws as much current as it can, and smits a continuous tone. Bad!
B: adding a 22Ω resistor tames the circuit. This works.
C: this wierd configuration also works without needing a resistor.

In all cases, the “T” (tone?) button has little if any effect. I think I can discern a slight tone shift, but it is minimal.

PX088A_schematic