hands on acoustic interface
Color your eurorack system
3 hp guitar spring tool in eurorack
passive
comes with 4 replaceable springs for different sounds
see demo
hands on acoustic interface
https://www.errorinstruments.com/a-53377378/new-on-error-welcom/raw-spring-nano-colors/
Available as an assembled Module and as a DIY project.
This Module is currently available.
$38