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#356 PX088A Audio Effects Chip

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


Here’s a quick demo…



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.


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.


Test Board

Thinking I might use a common board for a few different chips, I laid out a version of configuration “B” Manhattan-style on PCB stock.



Here’s a quick demo of configuration “B”:


And alternative configuration “C” for comparison:


Credits and References

About LEAP#356 AudioMusic Chips
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This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.