When I purchased a "Sega CDX power supply" from sega-parts, they sent me a Model 2 Genesis one. I don't seem to have any problems using it with my CDX, but with my X'Eye it causes issues.

Just get one from Radio Shack. They should have a 9v, 1.5a power supply. The voltage being a little off shouldn't hurt it, I don't think. I do know that the amps can be higher, just not lower.