Harmonic Percolator Troubleshooting

Forum dedicated to helping people debug and troubleshoot non-functional pedals or builds. Please use an clear and informative title, indicating circuit and basic problem. Don't forget to mark the issue as fixed if this is the case.
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megatrav
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Post by megatrav »

Hi, I originally posted this in the wrong place..

I am trying to build a Harmonic Percolator based on the layout on the tagboard effects blog spot (http://tagboardeffects.blogspot.com/201 ... lator.html) with the switch to take the diodes out.
Whenever I plug it in, I get a horrible squeal when it is engaged. The bypass works just fine.
I thought that I might have the germanium transistor in the wrong way, so I flipped it (crossing the middle leg over) and it didn't resolve it. Maybe its something obvious that I am missing
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Any help is appreciated

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mauman
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Post by mauman »

Check the bypass footswitch, it looks like lugs 2 & 3 might be shorted? I can't see lugs 8 & 9 but check them for a short as well. If the bypass switch allows output to loop back to input while the circuit is active, you'll definitely get oscillation (more than you would want from this circuit, at any rate.)

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