I had a similar situation with my Crown XLS 2002 amp when I needed a 25ft cord for a gig. I was worried about power drop too, but getting a high-quality
extension cord transparent made all the difference. It’s cool because you can actually see the internal wiring, which gave me peace of mind about the build quality.
I found mine after looking into options on a site like Global Sources, and it handled everything perfectly—no overheating or power issues, even when the amp was cranking. Just make sure to go for at least a 14-gauge wire, or even 12-gauge if you’re pushing the amp hard.