I have the following foot pedals: * [MXR Dynacomp][1] * [Pro-co RAT II][2] * [BOSS CE-5 (Chorus Ensemble)][3] * [Korg AX30G][4] ... and of course would like to add more. :) I'd like a single power supply to <strike>rule</strike> power them all (for example this [Chord 9Vdc Power Bank][5]). I'm not necessarily after a recommendation per-sé, as it'll go out of date eventually. However, what should I be checking/looking for when trying to choose one of these adapters so I get one that will work without frying my gear. I'm thinking adding up amps and checking centre-pin polarity etc, but I don't know for sure. [1]: http://en.wikipedia.org/wiki/MXR_Dyna_Comp [2]: http://en.wikipedia.org/wiki/Pro_Co_RAT [3]: http://www.bossus.com/gear/productdetails.php?ProductId=136 [4]: http://www.musicgearreview.com/reviews.php?man=Korg&cat=Guitar_Effects&mod=AX30G [5]: http://www.amazon.co.uk/Chord-9Vdc-Power-Bank/dp/B000NVU9GG/ref=wl_it_dp_o_npd?ie=UTF8&coliid=IMPMQFWACBE2D&colid=393V5K5ZB37K5