Vintage Tube amps

Tubes do tend to have a marvelous midrange, but not only midrange the whole thing top to bottom if you're listening to a good one. Tubes of course are obvious but in reality only a part of the equation. Transformers, caps, diodes and the overall design or topology all play important roles and contribute to the sound you hear. If it was rolled off at either end that was as likely transformers, or something to do with the amp and the speakers, and all the rest of the system as well.

Neither tube amps nor vintage amps are anything you can group into broad generalities like you are talking about. You really do have to take them just like everything else, one at a time.

There are great vintage tube amps that will give you plenty of the sound you are looking for. Especially if you are happy to use subs, that will allow you to use some high sensitivity speakers without having to worry about bass, you can focus on midrange and up, should be plenty of candidates to choose from. A modded/upgraded ST70 probably would fit the bill. But there are plenty of others.

Depending on your budget and timeline, I just ordered a Raven Blackhawk and will be listing my Melody when the Raven is ready in a month or so. https://systems.audiogon.com/systems/8367 Something like this will definitely perform like you are looking for.

Obviously, most tube amps are not like that, but the sound of any amp is affected by the impedance curve of the speakers it is driving.

A high output impedance tube amp + a speaker with a low and falling impedance in the high frequencies will sound rolled-off! Conversely a speaker with a rising impedance in the bass frequencies will sound excessively heavy! 

Tube amps with output impedance of 1 ohm and higher will act like "tone controls" as they track speakers' impedance curves! 

Most of the best systems I’ve heard had tube amps....some old, some new. How they sound depends on a ton of variables, but the sound on all of them can be tailored a bit by the tube choices. At their best, tube amps offer great frequency response, and a holographic image.