Attenuator

Eurorack attenuator dongle

Features

• Passive attenuator, approximately -20 dB
• A small dongle that can be patched between modules or devices
• Bidirectional - plug it in either way around!

Notes

I made two of these small attenuator dongles for my Eurorack system because I kept running into situations where I want to knock down the signal level by a large amount. I have a fancy attenuverter module but I just wanted something small and simple that would leave the attenuverter free for more important jobs.

My particular reasons for using this attenuator are:

• Using a tuner (or other external device) - I have a tuner that has trouble with the signal level straight out of a Eurorack VCO, so I keep one of these attenuators plugged into the tuner.
• Bad design choices - I made the pitch mod inputs on my oscillator modules way too sensitive. Even though there's an attenuator control on the input, it's hard to get a reasonable vibrato when I patch in an LFO. Sending the LFO through this attenuator gives a much better range of adjustment on the pitch mod input, for most purposes.

The device is assembled on a small piece of stripboard PCB. See the attached layout diagram.

Please note that I am a hobbyist, not a trained electronics engineer. No guarantees!

Software Used

• KiCad 7.0.8

© 2024 Len Popp CC BY
This work is licensed under a Creative Commons Attribution 4.0 International License.