I was considering buying another AES system recently(I used to have one long ago, not anymore...) and looked on eBay. I notice that 99% of the listings are for JPN AES systems.
Where's all the US systems? Can a JPN system play US games? What about the power supply issue(different current/voltage)?
I tried doing a search for "US AES systems" on here, but had a hard time finding threads that explained what I wanted to know.
People like you are the reason US systems are practically non-existent and in such artificially high demand.
The Neo Geo has no region locking at all, any AES will play any region cartridge. However, the BIOS chip determines the language used. a Japanese AES plays everything in Japanese. If you were planning on getting a Unibios chip, then there's now zero difference at all between a Japanese and USA AES.
As for power, you could probably use the Japanese 100v adapter that would come with an AES, but if that bothers you, it's not hard at all to find a USA 120v equivalent. You just determine the voltage your AES uses and find a local power brick that fits the voltage, amps and polarity needed. Local second hand shops are a great place to find loose power adapters.
Source: Jamma-Nation-X
Okay, maybe it's not overly easy but power bricks aren't rocket science either.
Game consoles that use external power transformers are all the same, they take a DC voltage, they don't care how exactly you're converting down from AC voltage, be it an official adapter or a random replacement you found that still fits the required output specs (volts, amps, polarity, barrel jack size). Being able to import an AES or a Genesis or Famicom and sourcing a local adapter for your country's power grid is what makes those systems awesome to import. Then you have consoles with shitty fucking internal transformers like the Saturn, Dreamcast and fat PS2. With those, you are forced to use external AC step transformers which can be dangerous if you try to skimp on quality.