AC or DC ?

Hi hopefully someone can help me out here:)


if a synth/drum machine/keyboard etc has a power input on the back of it saying DC INPUT , i use an AC or a DC adaptor?

i would have thought DC yet i am constantly finding manuals and other sources telling me AC.

the 3 units im tryna suss out here are,

Roland MC-202 -

ive read that i should use a Boss PSA-240 9v 200ma AC adaptor. i have one and it makes unwanted noise on the signal.

i also have used (and it works fine) a generic 9v
180ma DC adaptor.



Roland PMA-5 -

has a DC input but the manual asks for a PSA series AC adaptor.


last but not least...

Roland TR-707 -

DC input 12v unsure of ma rating.


thankyou ;)

seems like a problem with naming conventions. to fully specify what an adapter does, you need to name the input and output. ie, AC/DC or AC/AC. something called just an "AC adapter" might be either of those. usually if something wants DC coming in, an AC/AC wont work at all, even at the correct voltage and amps (and you risk damaging it).

i think whats happening is theyre calling these adaptors AC that output DC like the boss psa series...

so it seems that if it says dc input its an "ac" adaptor that outputs dc.

confusing indeed :shock: