[sdiy] backwards pots. Whats the deal?

[Donald Tillman]

Not directly related, but possibly of interest...

This is also an issue with electric guitar wiring.

The standard Gibson wiring for a guitar with two pickups has a (forward) volume and tone control for each pickup, and the pickup selector chooses either or both, where it shorts the wipers together.  So turning down one pickup in the mix turns them both down.  Which is counterintuitive.

So some guitar models wire their volume pots backwards.  Specifically the Fender Jazz Bass and many Rickenbacker models.  This provides a more sensible pickup mix at the cost of a resistive load on the pickup at lower volume settings.

Why did Gibson standardize on a shorting pickup mix?  The intent was that the guitarist would use the pickup switch to select between the two pickups like presets, each with it's one volume and tone control.  And the middle switch position, with both pickups on, was considered less important.

  -- Don

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Don Tillman
Palo Alto, California
don at till.com
http://www.till.com