SOLVED AION Lithium depth control is not linear

harmaes

Active member
I’ve juist build a Lithium from AION Fx which is an EHX Small clone with a mix control and a depth pot instead of the 2 way switch.
I didn’t get any chorus at first which turned out to be a broken bias trimpot.

In the description it says this about the depth control:

Depth knob
The original Small Clone only had a 2-position depth switch to change the intensity of the chorus sound. We’ve converted this to a potentiometer that allows fine-tuning the depth across the whole range and beyond, instead of being stuck with two presets.

I was expecting a linear depth control but it’s not behaving that way. I demonstrated that EHX pedal in the past and I remember the two settings also affected the rate where one side could go into Leslie kinda territory and the other was slow(er). The issue I have is that the rate is not affected linearly by the depth knob. Somewhere around the center there’s a max rate which reduces to either sides. Maybe that’s the design Kevin did but its not very user friendly IMO.

I have no deep knowledge about the MN3007 or the CD4047 so maybe someone can validate that the behavior of the depth knob as I’m describing is correct?

Here’s the documentation and schematic: https://aionfx.com/app/files/docs/lithium_documentation.pdf
 
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Anyone trying to build this one, the TL022 can be the cause of this. Replacing it with an LM358 should solve it. I replaced it with a TL072CP and the depth now works linearly before it increased the rate in the middle of the depth pot and both sides (cw/ccw) reduced it.
 
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Thanks for the info, glad you got it sorted.


Quick question for you:

C14 is a bi-polar (bipolar) electrolytic 2µ2 cap. Did you use the specified part or did you McGyver a couple of Polar Electrolytics in series to make the bi-polar?


+4µ7 <> 4µ7+ = 4µ35 bipolar
or
-4µ7 <> 4µ7- = 4µ35 bipolar

Either way above works, just don't connect positive of one cap to the negative of the other cap.


Quick question for you and/or anyone else:

What I'm wondering is, I've got a bunch of 2µ2 box film caps, and am tempted to just shove one of those in.
 
Thanks for the info, glad you got it sorted.


Quick question for you:

C14 is a bi-polar (bipolar) electrolytic 2µ2 cap. Did you use the specified part or did you McGyver a couple of Polar Electrolytics in series to make the bi-polar?


+4µ7 <> 4µ7+ = 4µ35 bipolar
or
-4µ7 <> 4µ7- = 4µ35 bipolar

Either way above works, just don't connect positive of one cap to the negative of the other cap.


Quick question for you and/or anyone else:

What I'm wondering is, I've got a bunch of 2µ2 box film caps, and am tempted to just shove one of those in.
I used a tant 2u2.
 
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