Stepped output resistor values with switches for music project

Thread Starter


Joined May 25, 2019

I am new on this forum. I am professional musician and use to be a computer engineer, I have done electronics in the past but it has been a long time.
My project is related to music gear and how to control some musical effects with a home made foot pedal that I want to build.
Now I am using an expression pedal to control some effects parameters in my effect processor. Basically it is a 100k potentiometer plugged into the expression port of the the effect processor which is a TRS jack connector. The TRS plug deliver 3,3V from tip to sleeve and the potentiometer give back the reduced tension from ring to sleeve.

So electronically speaking, I have 3,3v at input of my circuit, now I use a potentiometer to have a variable tension from 0v to 3,3v at output.
I would like to replace the potentiometer with 12 switches to have 12 stepped output values :
Press switch 1 : output = 0v
Press switch 2 : output = 0,3v
Press switch 3 : output = 0,6v
Press switch 4 : output = 0;9v
Press switch 5 : output = 1,2v
Press switch 6 : output = 1,5v
Press switch 7 : output = 1,8v
Press switch 8 : output = 2,1v
Press switch 9 : output = 2,4v
Press switch 10 : output = 2,7v
Press switch 11 : output = 3v
Press switch 12 : output = 3,3v

Note that the tension at output needs to stay still once the switch is pressed, and change only when the next one is pressed.

Do you have any idea how to achieve this?
Any help will be very appreciated.

If you are curious about my music, you can go check my YouTube channel, I play an electric hurdy gurdy :


Joined Feb 20, 2016
Are you able to build an Arduino controlled device? that is the way I would go. Then a momentary switch can trigger the required output and hold it until changed.
An R-2R ladder on the output is used to generate the voltage, but you may get away with using the analogWrite function and filter the PWM.
My vote is the R-2R approach.
Here is a little bit of info...

As a bonus, if you want, pre-defined sequences could be programmed too.