SET the best?

@Atmosphere - boring is kind of crude for my description so I'll tell you what my 10 year old at the time said- We were listening to Metallica comparing the Luxman 590AXII to the SPEC (intro integrated but like $6K) with Devore Nines.

He thought through the Luxman, the band had authority and energy- real drive! He said through the SPEC they sounded like they were dressed in their Sunday best sitting neatly around a dinner table.

The amp had fine detail and was dead quiet but when you listen to metal the system should convey the kind of energy that makes you want to throw a chair through the window or at least be able to get you excited. It was awesome with electronica on the other hand.

We always seem to hear this when guys talk about an amp or speaker being good for this or that genre. For me there has to be some magic in the midrange without being too hyped that it gets fatiguing or makes my ears ring at 85 db.

So this is a mono set? I assume you recommend your tube pre, or is that coming soon too?  You seem to be the closest we have to a genius on this site, I hope you knock it out of the park!

due to to the presence of the 5th and 7th harmonics, which tell the brain how loud the sound is.

Intrigued. Could you please point me in the direction of any credible scientific documentation which arrives at this conclusion?

So this is a mono set? I assume you recommend your tube pre, or is that coming soon too?

@bjesien We've been making preamps since 1989- the MP-1 was the first balanced line preamp made for home audio.

Intrigued. Could you please point me in the direction of any credible scientific documentation which arrives at this conclusion?

@pesky_wabbit  This fact that the ear/brain system uses higher ordered harmonics (5th and up) to sense sound pressure is well known and you can prove it to yourself with simple test equipment. All you need is a speaker, an amplifier, a VU meter and a sine/square generator. Set the generator to sine. Run the signal into the amp and then to the speaker. Use the VU meter to show the level. Set the level to 0VU. Then cover up the meter and turn down the volume. Set the generator to squarewave output. Keep the meter covered; run the volume up until its as loud as it was before. Uncover the meter and you'll immediately see what's going on- typically the meter will be showing -20dB or less. Square waves have lots of higher ordered harmonics and sine waves have none.

On page 31 of the Radiotron Designer's Handbook (3rd edition, from the 1930s) we see that it was understood back then that the higher orders were more audible and so should not be created in large amounts for the critical (or casual) listener. Here's a link to a pdf of that tome:
https://worldradiohistory.com/BOOKSHELF-ARH/Handbooks/Radiotron-Designer%27s-Handbook-3rd-Edition.pd...You might want to read the chapters on audio power amplifier design; its quite interesting to see how well were understood the principles we use today. Keep in mind that the Radiotron was meant as a guide and is not greatly in-depth.

General Electric did a study on this in the 1960s which I read in college but I've yet to find that study on line.

Suggest you look at my thread: “Is there a SS amp that can satisfy a SET guy?”:
https://forum.audiogon.com/discussions/is-there-a-solid-state-amp-that-can-satisfy-a-set-guy?highlig...
Mostly, the answer is no. With 1 or 2 exceptions.
Bakoon and AGD
I now live with my destination amps-AGD Audion mono blocks.
By far, the best amps I have experienced in 50 years.
They have the magic of great SETs with the detail and impact of great SS. Yes, SETs can be magical, beautiful and musical. But the metaphor from the above thread that I held on to is: “SETs are like a sonic screwdriver loosening the sound.”. The detail and scope of the AGD SQ speaks to the “magic” of a great Class D GaN amp.
Shockingly real. After years of SETs, I do not miss them at all.

Well one would have to have heard each and every class A, AB, D, GAN, Tube push/pull, OTL, Chip and Hybrid amp produced to say only one or two amps. Right?! Hear them all in the same exact system. Right?! 
We must be careful making sweeping statements that are always based on such little experience relative to all that is out there.