Much of the guitar's signal is in the midrange, so the "shape" of the midrange reproduction contour is very important when balanced off the bass and treble. Here is your obscurity for the day: just because there isn't a midrange knob doesn't mean there isn't a midrange control built into an amp.
Huh? Back in the 1970s I used to play a 1966 Gibson GA-55RVT
Ranger amplifier. It was a 50 watt, 4x10 amp, very much like the Fender Super, but with a far, far different sound. It had a much gentler treble and broke up more gently and at a much lower volume. The only way I tended to like to run the amp was with the midrange and volume controls maxed out. I sold that amp because it lacked a master volume control and I didn't want to irradiate myself anymore. Fast forward to a couple of years ago when I stumbled across an example of its little brother, the GA-45RVT
Saturn.
The main differences between the Saturn and the Ranger is that the Saturn has only two 10" speakers, it has a smaller transformers so that it only puts out 35 watts, and it doesn't have midrange controls on the channels. Well, at least it doesn't have midrange
knobs. The amp sounded a bit thin so I pulled up the schematics of the Ranger and the Saturn and looked at the midrange control. Lo' and behold I discovered that they were very nearly identical except that the Ranger had the potentiometer to control the midrange and the Saturn had a fixed resistance, basically the same as running the pot all the way closed, in the same position. Makes me want to go in and jumper the resistor to see if I can fatten up the amp.
I've got a similar situation with a newish Fender Custom '68 Princeton Reverb. Fender wanted to voice it more like a Bassman so they altered the tone stack to increase the midrange - a fixed mid increase. You can go in and alter a couple of components and jumper one connection and you've got the standard Princeton.
Soooo... Whether an am has a pleasant midrange can be a function of a midrange curve set by something other than a midrange knob!
Bob