I donated a new NP31 in a country where 220v is used. I forgot to bring the Yamaha AC adapter, but it was easy to find a replacement. When you look for a placement power supply, the voltage must match always, but on the ampere, you can go higher but not under. That's why the one on Amazon will work but not the Live Wire Solutions you found. Also, polarity should be always checked. If I remember correctly, just about all Roland power supplies are center negative. With Yamaha center positive. You might want to get a multi tip/multi voltage power supply on eBay which can be used for many devices.