I just bought a used Akai headrush II and in the description it reads

"Beware of using these with a low amp 9V chain as they are power hungry and sound bad without enough current."

Can someone explain this in simpler terms? I'm just starting to use effects and I don't understand what a lot of this means

Thank you in advance!
They want to make sure that you're using a power supply that can supply enough current (milliamps, mA, why they say "low amp") because if it's a wimpy  supply the repeats sound bad. 

All this means to you is that you need to make sure that the power supply you're using has more than 165 mA of output current capacity, and is a center-negative 9V supply. Some power units like the Pedal Power 2+ have some outlets that are less than that and some that are more, but your average single-pedal adapter like the Boss PSA-120 tends to be 200mA or more, which is plenty. The "chain" part in the description is there because some people string a bunch of pedals together on the same adapter like christmas lights. A good adapter like the One Spot will have plenty of juice for a whole bunch of pedals, but daisy chaining ten pedals on a single Boss adapter might not work.
Have a look at the link in my signature "Guide to powering your pedals".

(Or whatever it says. Sig doesn't show up on my phone)
Last edited by CodeMonk at Mar 14, 2017,