Getting the best from Usher Mini Dancer II's

Hoping some in the A'gon community can help with ideas and suggestions. I recently got a pair of used Usher Mini Dancer II's, but have been underwhelmed by their performance. I'm using a Yamaha AV receiver, which of course is the issue, and wanted to hear what amps match well with these speakers.

I have an older NAD amp sitting around that I'm going to try, but figured I'd ping the community to see if anyone has had success in a good matching amp for these speakers.

Thanks much!