Part 3. In this post, we modulate the oscillator we previously built from a Quad NAND CMOS chip. We use another gate from this CD4093 chip to achieve this. All we need to add is another capacitor and resistor to modulate the second NAND operator by the first one.
In this series, we build a simple LFO module for Eurorack. After an initial design phase, we’re now ready to test it on the breadboard to see if it actually works. We only need a handful of easy to find components to build a single LFO based on a relaxation oscillator.
Almost no modular synth patch can go without the use of a low-frequency oscillator (LFO). So I decided to build one myself to get my hands dirty on building modules for my Eurorack system. It is based on a fairly simple relaxation oscillator circuit.