#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.
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
- Alice Music Voice Module Tone Loop Control IC Chip Board for DIY/Toy 3V-4.5V - seller on aliexpress
- S8050 Datasheet - NPN BJT
- Für Elise
- ..as mentioned on my blog