Tube amp for "difficult" speakers,,,

The impedance specs you post above are pretty favorable for a push-pull tube amp running on 4 ohm taps, IMO, since the peaks and dips are relatively flat.

So, I think the recommendations above would be good possibilities...namely VAC and Music Reference.

I have owned a couple of VAC amps including the VAC Phi 110/110, which was stunning. I have heard the VAC 30/30 Signature, which was also magical on a pair of Merlin speakers (although you'd need the extra power of the VAC 70/70).

Have fun!

I forgot to say, a Velodyne DD18 with a sand bag on top. I love these tweaks that are cheap and make a clear improvement on the sound...Thanks Tvad, I will.

listen to some manley neo classic 500s or older reference 500s I dont think some of the other suggestions on this thread will drive your speakers adequately

Which amps mentioned would you not recommend and why? I'm interested to learn the reasoning.

I dont have personal experience with your speakers but I have pretty inefficent speakers myself and have owned the Rm9 (not special edition) and Vac ren 70/70 both great amps but were a little lifless compared to the manleys my experience is that there is no shortcut you need alot of output tubes and massive transformers( I also owned joule grand marquis.) If you are moving from solid state I think the others will leave you a little underwhelmed unless you get a more efficent pair of speakers. But no doubt a tube amp is the way to go!