Positive ground and input output jacks.

Frequently asked questions regarding powering your pedal.
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the9mmsolution
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Post by the9mmsolution »

So I'm having a lot of trouble wrapping my brain around the concept of positive ground. I built myself a beavis-boardesque prototyping setup. In an enclosure i have a true bypass switch, battery, volt starve etc with leads going to breadboards. I've managed all that and have built several fuzz circuits of the modern (?) npn variety with much success.
Today I built RnFR's toecutter, using PNP Ge trannys, and I worked out what parts of the circuit go to + ground and which parts go to -9v. The only thing I can't figure out is what do I do with the input and output jacks? Does the sleeve remain negative from the battery? or should that be positive, too? In that case, I can just attach my battery snap the other way around. I've searched for build instructions on old fuzz faces and things I know are positive ground, but it still isn't clear to me what to do.
Thanks!

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mysticwhiskey
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Post by mysticwhiskey »

The input and output jack sleeves are positive ground as well. See this layout of the Fuzz Face on Tonepad: http://tonepad.com/getFileInfo.asp?id=82

On the positive-ground version of the schematic, the ring terminal of the input jack is switching the positive ground to the sleeve when an input jack is inserted.

Because the signal ground and power grounds are connected together in a typical pedal, if you have the battery negative going to the jack sleeves it would short-circuit the battery.

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the9mmsolution
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Post by the9mmsolution »

Well I messed that one up then. Thanks for this!

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