This is probably a super noob question, but do these use AC or DC adapters?

I was given a second hand one today, and I can't get it to turn on. The back of the box says 9V DC, which I have, but online everywhere seems to say it needs 9V AC.

I downloaded the manual but that confused me even more, as it has a drawing of the back of the box which says dc, but the text box says AC.

(bottom of page 6 at: http://cdn.roland.com/assets/media/pdf/ME-30_OM.pdf)

I put batteries in, and it worked for a bit before stopping again, but it could just be that the batteries aren't supplying enough power.

Not super invested in it, as it's a pedal my uncle wasn't using and I hadn't expected to end up with. Now I'm curious though, and it's going to annoy me til I fix it lol