Well, it's an adapter. But I didn't buy it for a Yamaha keyboard but for a Behringer Odyssey, as I lost my adapter. Works fine. Like most adapters, as long as the connect is the same and the voltage/amps are correct, it will work with any piece of equipment needing a similar output. The only negative is the actual direction of the prongs--if you are using a power strip and need every plug, you will have to make sure it is plugged into the end receptacle, or use a short extension cord to plug it into a different part of the strip. But hey, the workaround is simple, and like I said, it works.