Phono preamp power cable not long enough. New wall wart or use an extension cord?

My power cord for the wall wart of my phono preamp isn't long enough to reach my power conditioner. What is the best solution to fix this issue? Should I look for an aftermarket wall wart or use an extension cord? If extension cord, does the quality matter? Or will a cheap brown extension cord be find? If I should search for a new adapter, where can I find a high quality one that won't have any negative effects on sound quality. I appreciate any advice.