If this speaker is used with tube amplifiers, the significantly higher impedance in the treble compared with that in the midrange will tilt up the high frequencies.
@soix This is a good example of how Stereophile comments are not always correct. If the amp is designed properly its very likely the output of the amp will not increase at all. This can be true even if the amp lacks feedback.
@mdemaio Since this is a lower efficiency speaker of only 87 dB (quite common with speakers of this size) you will need some power. But you may not need all that much. I would expect a Dynaco ST70 to do quite well on this speaker. The load is benign so you have a wide range of amps that will do the job.
But just to be clear a lot will depend on how you play your system and the size of the room. My speakers in my bedroom system are the same efficiency and I drive them with a 5 Watt/channel integrated stereo tube amp that has no problems playing plenty of volume; in fact I've never run it out of gas. My bedroom is not that small; it takes up the entire second floor of my home.
Dynaco made a small integrated amp called the SCA35 which might be a consideration. I don't know if they still make it; if you get an older one it will have to be refurbished. But you could do that for under $1500.00.