Hey guys, I bought my Boss os-2 pedal new. I find there is a high pitch buzzing sound coming out of the amp from the pedal when a power supply is plugged in. When I run it off battery power, there is no buzzing. I have other Boss pedals that I bought new and there is no problem with them either way. I tried buying a new power supply, but got the same result. I really don't want to have to buy a noise suppressor pedal or anything else like that, so any help as to why it would be doing this is appreciated.
that sometimes happens to me, are you using a daisy chain or on a multi-plug adapter? These seem to be one reason why it happens to me on my od3 bass pedal. Usually switching to a separate plug socket fixes it!

On second thought have you the correct voltage plug adapter? My Boss things usually have a 9volt requirement
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Last edited by Benny_W at Jul 29, 2010,
have you tried plugging in your stuff in different outlet? or setting up your stuff in a different room? it might have something to do with the electrical in your house. (i know.. weird)
Are you using a filtered 9V negative tip power supply? Anything else will cause problems.
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Yup, 9v negative power supply. I use only on direct power supply to it, no daisy chains or anything. I doubt it's something else electrical in the room interfering; none of my other boss pedals make the noise at all. I shall try plugging it in elsewhere and let you know.