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!
I have used several amps with my ushers - musical fidelity, nad, jolida, pass labs, rogue audio - all with good results. they are fairly easy to drive. They are also revealing, and you are correct that your Yamaha is the weak link (although a very good home theater rig Im sure).
I am using the rogue Cronus magnum with great results. Using the 4 ohm output. The DMD tweeter with an all tube amp is a very good pairing IMO.
Do your Ushers have the beryllium or DMD tweeters?
I have home brew speakers using Usher drivers and custom crossovers. I use a Doge 8 Clarity tube preamp and Monarchy Audio SE-100 Delux MKII class A mono blocks. Preamp, used ran me $1500 with good NOS tubes, the amps were $980 the pair as factory refurbs direct from Monarchy Audio back when the economy was at its low point.
Very happy with the combo. Detailed, musical, yet neutral, with a big sound stage
The Usher speakers are good enough to take advantage of better gear. In my case I traded up on better gear without the need to trade up speakers. The improvement was easy to detect.