#521 CK9561 Audio Effects Chip

Figuring out how to use the CK9561 music chip with 4 sound effects - alarm/siren/weapon sounds that sound strangely familiar if you have ever walked through a toy department at Christmas!

Here’s a quick demo..

Notes

The CK9561 is the latest in a series of music effects chips I’ve been testing. The CK9561 is sometimes labelled KD9561 of XK9561 - I presume these are just different manufacturer’s names for boards based on the same chip.

The module,with pins attached for testing on a breadboard:

Usage and Schematic

The chip requires just a few external components to operate:

• the resistor (100kΩ-390kΩ) controls the speed of the effect - higher resistance slows the effect down
• a small signal NPN transistor (I used a 2N3904) for controlling the speaker
• and switches - not shown in the schematic below:
  • the effect is “always on”, so a switch in the power line can be used for on/off control
  • switching connections “1” and “2” between unconnected/pulled-low/pulled-high select from the range of sound effects according to the following table

Testing on a breadboard:

I also added the chip to one of my “audio effects” copper-clad test boards. I’ve added a few components:

• resistor is 100kΩ fixed + 200kΩ variable resistor
• mini push-button switch on the power connection (effect on/off)
• a 3-position switch for toggling pad 1 between unconnected/pulled-low/pulled-high
• mini push-button switch on pad 2
• external 8Ω speaker

Credits and References

• KD9561 CK9561 Alarm Module - from a seller on aliexpress
• 2N3904 datasheet