# Chaos machine expression pedal pot values



## Bobbyd67 (Jul 5, 2019)

I was just wondering... do the expression jacks need a 1m and 100k expression jack like the interstellar orbital from eqd ? If so can i add some resistors on the jacks so i could have the same range with a traditional 10k expression pedal ? :/. Thanks !


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## zgrav (Jul 5, 2019)

The expression jacks replace 100K and 1M pots on the PCB, so I think those are the values you need for the expression pedals.  I don't know how you could get either of those ranges by adding resistors in series and/or parallel to a 10K pot that would give you that same sweep range.


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## zgrav (Jul 5, 2019)

I saw a post suggesting that amplifiedguitarparts.com sells replacement pots for expression pedals in case you want to go that route.


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## Bobbyd67 (Jul 5, 2019)

I dunno about making a expression pedal just for that pedal xD. I guess i will try my expression pedal first... if it sounds bad i will try to solder a 2m and 200k resistor across the switche lugs of each expression jacks to see if that helps ! But thanks for the info zgrav


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## Robert (Jul 5, 2019)

Bobbyd67 said:


> I was just wondering... do the expression jacks need a 1m and 100k expression jack like the interstellar orbital from eqd ?



That's correct.   It'll still work, it just won't have the same range.



Bobbyd67 said:


> I dunno about making a expression pedal just for that pedal xD.



Couldn't agree more.    If _anything, _you might consider putting some trim pots on each side of the jacks so you can "center" your expression pedal into the sweet spot.


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## zgrav (Jul 5, 2019)

using trim pots to adjust to the sweet spot of the 10k range would certainly help.   seems like the 10K would give you 10% of the range of the 100K pot, which could hit the spot you would want for the pedal.   maybe that would be enough for the sweet spot for the 1M pot as well.   

Maybe you could even use a dual ganged pot so you could have one knob to add and decrease resistance to dial in your sweet spot.


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