Author Topic: how to add an input for an expression pedal  (Read 696 times)

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Offline fbirambaTopic starter

  • Newbie
  • Posts: 1
  • Country: fr
how to add an input for an expression pedal
« on: May 08, 2020, 09:36:12 am »
Hello I would like to add an input for expression pedal on my effect pedal for guitar.
The expression pedal is a potentiometer of 10k (generally) controlled986438-0 with the foot.


This pedal will control a 50k potentiometer (if the exp pedal is not on, the user can use the normal pot) there will have a switch to choose between exp pedal or normal pot

I do a schematic with vactrum vtl5c3/2 but it's expensive. If someone know an Ic to replace this ...
I post the schematic and tell me if there's mistake

best regards
franck
 

Offline sam[PS]

  • Contributor
  • Posts: 46
  • Country: fr
Re: how to add an input for an expression pedal
« Reply #1 on: May 15, 2020, 11:18:03 am »
You don't need any IC for that, just a Jack socket with switching contacts (they takes different names from one manufacturer to another)  here is an exemple : https://www.neutrik.com/en/product/nmj6hc-s

On one side you got the three terminals from the jack plug and on the other side you got three corresponding terminals that we'll call the switched terminals. How it works is when no jack is plugged both side are connected, but when you plug a jack that mechanically disconnect the switched terminals so they end up floating.

So what you do is connecting the three jack terminals to your circuit in place of your internal pot, then you connect the internal pot to the three switched terminals of the jack socket and Bob's your uncle.


Just my 2cts...
 


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