The schematic of DR-110 is:
![](https://gaje.jp/blog/wp-content/uploads/2020/01/bossdr110-1024x759.gif)
For this circuit, each percussion element seems to sound when you put a negative pulse of width 1 ms. I’ve put oscilloscope to observe the pulses come as expected.
Here are the pulses to the bass drum and output:
![](https://gaje.jp/blog/wp-content/uploads/2020/01/bd-1024x444.png)
![](https://gaje.jp/blog/wp-content/uploads/2020/01/bd2-1024x444.png)
The pulse width looks to be around 1.3 ms.
These are the pulses to the snare drum and output:
![](https://gaje.jp/blog/wp-content/uploads/2020/01/sd-1024x444.png)
![](https://gaje.jp/blog/wp-content/uploads/2020/01/sd2-1024x444.png)
For the hand clap, I only took pulses:
![](https://gaje.jp/blog/wp-content/uploads/2020/01/hand_clap_pulses-1024x444.png)
This is a simulated output of the bass drum circuit:
![](https://gaje.jp/blog/wp-content/uploads/2020/01/image-1024x731.png)
The output would be weaker when the pulse is narrower:
![](https://gaje.jp/blog/wp-content/uploads/2020/01/image-1-1024x731.png)
A wider pulse gives a stronger output, but the waveform starts distorting significantly at certain point.
![](https://gaje.jp/blog/wp-content/uploads/2020/01/image-2-1024x731.png)