I have a decent amount of effects pedals that I use in my guitar rig. Since I'm not really a fan of changing batteries every three or four hours, I try to use a DC adapter for each one(some of them came with the adapter, some did not). I rarely use all of the pedals at the same time, so, I have some adapters that are free to use elsewhere. However, upon closer inspection, I noticed that they almost all have different current ratings; the voltage is the same 9V DC as is the polarity(negative center). My question is, is it safe to interchange some of these adapters, and could someone explain to me why or why not?

Thanks,
Drew

 

You could make up a lead to place a current meter in line with one supply to measure the actual current each box draws.
There is no problem running a higher current supply into a low current device. The problem just may come up if you have a box that tries to draw more current that the power supply is rated for. As long as the voltage and polarity are correct, bigger current capability is good.

 

Thanks. That does help explain a few things. For instance, why the latest pedal I bought has a "greater than or equal to 200mA" figure in the tech specs. Most of the pedals just give a specific current rating. I'm going to say this out loud just to make sure that I got it right: Higher current than rating=good. Lower current than rating=bad, but would probably do no damage, just wouldn't work. Incorrect voltage=very bad. Incorrect polarity=very bad. I want to be as informed as possible to avoid frying any of my expensive gear, or even my cheap gear, or frying myself, etc.

Drew

 

Lower current than rating=bad, but would probably do no damage, just wouldn't work.

It does depend on the overload. If, for example, you were to put a 12V headlight lamp on a 12V 200mA power supply, and the power supply had no real overload protection, as is the case for most plugpacks, the supply would be damaged.

But otherwise, yes, you have it now