I'm about to land a vintage ("green") Electric Mistress, but I'm wondering how I'm supposed to power it safely. I've heard that I only need a 12 v adapter, since the pedal limits the 18 volts down to 12 on the inside anyway, but I'm unsure if my adapter cable works. I got a Boss-style-to-1/8"-audio-plug adapter with a power supply I bought a couple of years back (Godlyke Power-All). However, the Mistress requires a "tip positive" plug, and I'm pretty sure a regular pedal power supply is tip negative. Is the polarity reversed within the adapter cable, or do I need to put anything in between?
I just want to make this absolutely sure, 'cause if you're gonna take risks with your gear, an irreplacable vintage pedal isn't exactly the optimal place to start.