Single Pot for Univibe rate (GEOFEX)

Frequent asked about building blocks: gain stages, buffers, clipping configurations, ...
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Diodes3Ground
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Post by Diodes3Ground »

I came across this while searching up information on univibe circuits:

http://www.geofex.com/circuits/ldrlfo.htm

Has anyone ever tried doing this when building a univibe or such? I'm designing my own vibe right now, and the ability to use a single pot and with an opto coupler instead of a hard to find double gang 100kC pot is very appealing. Problem is, I have a bunch of questions about implementing it (ie. ideal part values, what D1 and Q1 should be, etc.).

Anyone got any tips? I think this could be used to achieve slower rate speeds and make it easier to add an expression jack, so I really hope some of you are able to help out. Thanks!

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Yazoo55
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Post by Yazoo55 »

I built the Univibe in a Wah shell project. An option for this project includes an optocoupler to avoid using a dual gang pot. The project file for this might be worth reading:

http://www.geofex.com/FX_images/UVICS-3 ... File-3.pdf

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Diodes3Ground
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Post by Diodes3Ground »

Cool, I'll check it out. Did you build it with the single pot option? If so, how well does it work?

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Yazoo55
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Post by Yazoo55 »

Yes, I managed to get the Vactrol from Banzai in Germany. It works fine, a really good project.

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