Updates!
I googeld a bit :p

Fund this: 12V DC 200 mA negative center

But also this: The TR-707 requires a special power supply, with a
limited current.. odd but true. a regular adapter won't work on a TR-707.

Whats up with that
Could someone affirm "12V DC 200 mA negative center"

Link to "special power supply":
http://www.livepa.org/board/viewtopic.php t=933&highlight=&sid=f8114f6a814c0635c4c6c626996af165


Thanks!