Quick Tip: Cowbell Eurorack Modular Synthesizer Patch Tutorial

Published on Oct 8, 2019 Perfect Circuit

"This quick tip shows how to make a cowbell sound inspired by the famous TR-808 cowbell.

You will need:
- a trigger source (clock or sequencer)
- one envelope generatorr (with exponential decay)
- two VCOs (voltage controlled oscillators) with square wave outputs
- a mixer with at least two channels
- one VCA (voltage controlled amplifier)
- a bandpass filter

The patch:
- square wave outputs of two detuned oscillators to mixer inputs
- mixer output to VCA audio input
- trigger source to trigger input of the envelope generator
- envelope generator output to VCA CV control
- VCA output to bandpass filter
- bandpass output is your cowbell

The TR-808 cowbell is one of the most distinctive of analog drum sounds, and it is a fairly simple sound to recreate with a modular synthesizer. Two square wave VCOs are mixed together and then run through a VCA. The VCA is opened with an exponential decay envelope and then run through a band pass filter.

To get a sound similar to the 808 you can tune your oscillators to 587 and 845 Hertz. The fun thing about building this sound in eurorsack is that you can try different tunings, or even modulate or sequence the tuning of the oscillators."

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