This is the Hex Oscillator PCB, a playground of sound built around the classic CD40106 Schmitt Trigger chip. It’s a simple, resilient, and endlessly creative circuit that turns logic gates into tone generators, noise machines, and experimental instruments.

Each of the six inverters on the chip becomes a free-running oscillator — capable of drones, chirps, glitches, and percussive pulses. By patching their outputs together with a few jumper wires, you can explore countless sound interactions and modulations. It’s a circuit that rewards curiosity more than perfection.

A little backstory

This was the first circuit I ever built that made sound, right after finishing my electronics course. It felt like magic — a handful of resistors, capacitors, and one little IC suddenly singing. That experience changed everything for me: it was the moment I realized sound could be sculpted directly from circuits.

Now, I’ve redesigned it as a robust, educational PCB you can explore and abuse freely. It’s practically indestructible — you can connect jumper wires anywhere, mix signals, and bend the circuit in real time. Perfect for classrooms, workshops, synth experiments, or your next noise art performance.

What makes it special

• Six independent oscillators — all based on the CD40106 Schmitt Trigger chip.

• Practically indestructible — experiment freely without fear of shorting or damage.

• Fully patchable — use jumper wires to connect outputs, inputs, and modulation points.

• Wide range of tones — from drones to clicks, sirens to chaotic interference.

• Simple power — runs on 9 V (battery, adapter, or modular bench supply).

• Educational design — a perfect way to learn about oscillators, feedback, and wave interaction.

• Maker-friendly layout — large pads, clear labeling, and forgiving tolerances for beginners.

What you get

• 1 × Hex Oscillator PCB (silkscreen + drilled).

• PDF with schematic, BOM, and basic patch examples to get you started.

Who it’s for

• Students and educators exploring audio electronics.

• Sound artists, synth builders, and circuit benders.

• Anyone who loves the raw poetry of electricity turning into sound.

Collect all 6 modules to create your own Audio Sequencer with modulation!