Integrated Amplifier for Sonus Faber Guarneri Evolution

I just purchased second hand SF Guarneri Evo's. They are the nicest looking stand mounted speakers I've seen.

I'm currently driving them with a NAD M33 and I think it is not the right match for them. There is no dynamics and they sound thin to me. I think these speaker have a lot more potential.The speakers are 4 ohms with a sensitivity of 86db. I listen to jazz, blues, instrumental and classical mostly.

My room is about 13 by 17 ft.. I have a Bluesound streamer and a Denafrips Ares II DAC.

I'm open to suggestions or recommendations for a nice Integrated Amp. I have a $10-12K budget. I rather buy it used, since I think I get a better value. I live in the Los Angeles area.

Thanks.