boss gt6b power supply polarity

[poomwah]

I've got a gt-6b with a 14 volt power supply that has the end missing. I have another end from something else that fits the jack in the back of the gt. I don't want to wire it backwards, how do I find out what the polarity is supposed to be. It doesnt say on the power supply or on the gt6. that little diagram that usually shows whether the center is positive or negative, no luck. So I don't know which wire is positive or negative on the power supply brc-120T or on the processor.

[poomwah]

ok, I hooked up a voltmeter to the wires on the power supply and found out which is positive. So I'm half way there.
anyone know about the plug? anyone have a brc-120 power supply that could check with a volt meter to see if the center is negative or positive?

[poomwah]

nevermind, I feel totally stupid, just realized its an AC adapter, there is no polarity.