Geofex Lera not working properly

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freshmex18
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Post by freshmex18 »

Built RG Keen's Lera from Geofex to add to a PedalPCB clone of the Walrus Julia.



https://postimg.cc/K3LKqVd2

http://www.geofex.com/article_folders/lera/lera1.gif

http://www.geofex.com/article_folders/lera/lera.htm

The On/Off switch works and the Lera does affect the sound of the Julia by adding a warble. The speed is quite fast. Neither the ramp up/down switch, the instant/delayed switch, nor any of the three trimpots have any effect on the sound.

I added the optional 10uF capacitor to the output of the 78L05 but no difference to the sound.

The build doc says "Once you get it wired up, check it out with a voltmeter on the 100uF capacitor to see that it does indeed ramp up and down, and on the + and - inputs to the opamp - they should go up and down in concert with the capacitor voltage." I checked and there is no ramp up or down on the 100uF cap. Unfortunately, the doc doesn't say what to do if there is no ramp up/down detected.

I did use an LM358 as I could not find an LM158. I also tried a RC4558 and no difference.
https://postimg.cc/K3LKqVd2

Can anyone see what I did wrong? Or is the Lera simply incompatible with the Walrus Julia?

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