Basari

• Jan 26, 2025
• edited: Jan 27, 2025

For a long time I’ve felt that I need a nice kick drum in my rack. In August I decided to build one and started looking around for circuits. I looked at the 808, 909, Moritz Klein’s EDU Kick, Thomas Henry’s Bass++, Juanito Moore’s DoublePlusBass, David Haillant’s DM77 and probably some others too that I have since forgotten. None of these really felt right for me. They all either didn’t sound how I wanted, or were too complex to build on stripboard, so I decided to design my own.

I really liked the efficient design of the Bass++, managing to create a whole kick drum with just an LM13700, a TL072 and some transistors and passives. It just doesn’t sound very good, mainly because the volume and pitch are controlled by the same envelope so you’re very limited in how you can shape the sound.

I also liked Juanito’s DoublePlusBass a lot. It’s based on the Bass++, but has added many improvements, like a dedicated pitch envelope, an exponential CV input and a wave shape control that can turn the drum from a triangle to a sine to a square. With all those additions comes complexity though. The DoublePlusBass has roughly 3 times the amount of components the Bass++ has, so it’s not really viable to build on stripboard.

I based my circuit on the Bass++, removing everything I didn’t need and adding features that I wanted. Here are my changes:

• Removed the “master volume” and “shell volume” controls.
• Removed the “impact tone” control.
• Added a dedicated envelope for the pitch with decay and amount controls.
• Added an exponential voltage-to-current circuit for the VCO.
• Added a switch to select whether the pitch envelope affects the frequency linearly or exponentially.
• Added a “sag” control, which sends some of the volume envelope to the pitch, adding another way of shaping pitch decay.
• Added a wave shape control, which I implemented by overdriving the input of the VCA in order to minimize component count.

I’m very happy with the end result. Basari sounds great and has a big range of kicks it can make, while having 1 less knob than the Bass++.

Demo

Schematic

Download:

• Basari-schematic.pdf (0.3 MiB)
• The KiCad project files can be found at https://codeberg.org/Sandelinos/Basari

Stripboard layout

Download: repository/Basari.diy (0.1 MiB)

BOM

Panel

Here’s the template I used to make the panel:

• repository/Basari-panel.svg (0.0 MiB)
• Basari-panel.pdf (0.0 MiB)

Photos