The answer has been found

[DanTheBluesMan]

it was this doohickey sitting in a drawer. I saw it today and asked myself:

"Self, what is this for? Why a female to male DC adaptor ... unless it's for swapping polarity?"

Snapped a battery clip onto a fresh 9v, plugged into the adaptor and into my Browne Protein. Success. I no longer need to make my own properly polarized clip.

I have absolutely no idea where this came from. My pack rat gene kept me from throwing it away. Serendipity smiled on me and brought it to my attention at a time when I needed it.

[S. Cane]

Oh, those do come in handy!

I just ordered a brand new power supply for a pedal chain project that involves several 9v center negative pedals, one 9v center POSITIVE pedal and one 18v center negative pedal. Yeah, a pain in the saddle hole to power without having trouble.

I needed isolated independent outlets for the center positive and the 18v pedals. The center positive will need... yes: an adaptor just like yours.

[DanTheBluesMan]

I wish I knew where it came from, so I could direct people to get one if they need one

[S. Cane]

I wish I knew where it came from, so I could direct people to get one if they need one

They're pretty easy to find, you can order them on eBay for instance.

I’d color tape it btw