Ernie Ball Expression Drive Volume Pot Trim

[pgorey]

I have been trying to make this pedal work because I like being able to control the amount of dirt with a rocker pedal.  However, as many people have commented on it, the fully down mode is not a bypass at all.  I solved this by building a dual effects loop switcher to properly bypass within my signal chain.  I also removed the output jack and threw a 100k A pot in its' place and side-mounted a new output jack.  I did this because the pedal has a super hot output that messes up anything after it in the chain.  Works great as a trim but now has affected the sweep of the rocker pot with a slight pop in the middle of the range.  I had to take the pully system apart to make room for me to work on the circuit/volume trim and new output and I'm curious if my tension and range were affected when I put it all back together and maybe THAT is the reason for the pop / funky range settings throughout the sweep.  My first guess is that the output section of the circuit is tied to the rocker pot but I'm curious what the pros here think. Thanks!

[idy]

I don't think there is a schematic out there for this, and the pictures at the EB web site look like it is digital, so kind of hard for you to trace.

It seems easiest to first experiment with the tension/travel of the treadle pot. You took it's mechanism apart once...

The old school wah pedals did have the pot "exposed" to the next circuit in line, it seems unlikely that this behemoth of DSP would be so crude.

[pgorey]

I think this is a completely analog circuit from my first look at it when I removed the board to get to the output jack.  I will remove the board again and snap a photo of it to see what ya'll think.  Will also look at the treadle tension and range setup again to make sure that's good.  Will likely start with that since it's the first part that needs to be removed to get the board out.