Testing for - ve versus + ve

[Jayco]

Hey all...

Really dumb question here, but I've never had to think about it before.

What's the easiest way to test to see if a pedal is + ve or - ve?

I assume its as simple as plugging a cord into the input jack (so that the circuit's electrical path is connected) and then testing to see whether the + side of the battery clip or the - side of the battery clip has continuity to the sleeve of the input cable?

Alternately, I assume you can also take the power cable (if using a power supply) and seeing whether the + or - side of the cable has continuity to the sleeve of the input cable?

The reason I ask is that I just purchased a new Pedal Power 2 Plus power supply and need to attach more than one pedal to most of the channels.  I know that it will automatically change each channel to +ve or -ve as needed, but you obviously can't mix the pedal types within each channel.

I tested all of my pedals and they APPEAR to be all -ve...  take a look and let me know if I'm off my rocker!!

Dunlop Mr. Super Crybaby (90's era)
MXR Dynacomp (block letter with LED)
MXR Distortion+ (block letter with no LED)
Ibanez TS-10 (80's era)
NPN Boost (home built)
ProCo "The Rat" (90's era)
Boss TU-12H tuner
Electro Harmonix Small Stone... modified to use barrel plug instead of 3mm plug

All pedals use the boss style plastic barrel jack with the exception of the Dynacomp and the Rat.  They both use 3mm, but they STILL seem to be -ve (yes, I know that the TIP of the 3mm is +).

So.. am I safe to think that these are all -ve pedals?  Every single one of them tested for continuity between the sleeve of the input cable to the - terminal of the battery clip.

Thanks,
Jim