Audio Systems: Turntable wiring, exact model number, ac dc adapter

Question
The servo(MMI-6TRW0)is marked with 9.12vdc. Does this mean that any ac-dc adapter that is between 9-12vdc will work? What is the best way to determine positive and negative on the unit and adapter?
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-----Question-----
I purchased a Sony PS-LX43P turntable. It was probably part of a rack system. The power cord is a three wire(small wire)with a three prong female plug on the end. Can a conventional wire with plug replace the factory cord? Is the power required 110 volts?
-----Answer-----
before putting a plug on, do a search on your exact model number and make sure it's the usa version. if so, then there's no problem, but since it's part of a rack system, it's not at all impossible that it requires 12 volts ac with ground..do model search before doing anything, and let me know what you find out and we will go from there.

Answer
a 9vdc wall wart will work, third wire isn't used, you just have to guess which is positive, unless you take unit (turntable) apart to see where wires tie in, board is marked + and - once you get to it. if you hook it up backwards, all it will do is run backwards, so initially just twist wires to end of wall wart's wires, if turntable spins backwards, just switch wires before making it a permanent connection. i'll be here if you need further...