Can we create a consensus list of the TONALITY of different amps/preamps/brands?

@hoodjem If you want correlation, here's what needs to be done:

1) show the distortion spectra of each amp

2) show the frequency at which distortion rises.

Rising distortion with frequency usually isn't a good thing. Ideally it should be a straight line. THD doesn't tell you everything, because usually its measured at a frequency too low to show the rising distortion. As a result, distortion can be quite a lot higher at higher frequencies than the THD otherwise suggests.

Distortion spectra is important since it will show what harmonics are audible or not. For example, if there is a lot of the 2nd and 3rd they might be able to mask the higher ordered harmonics. If the higher ordered harmonics are not masked, they can contribute to harshness and brightness, two common complaints about solid state (which is why tubes are still around 60+ years after being declared 'obsolete').

These are engineering problems that are solvable and some do it better than others. So now you have something to look for in the measurements (if you can find them; these measurements are not always published).

https://forum.audiogon.com/posts/2548923
"What…No McIntosh…conversation done!"

I would love for you to suggest a time-number (or position) for any McIntosh

amps or preamps, with which you are familiar.  That would be most helpful. 

https://forum.audiogon.com/posts/2548923

"hoodjem. Pls explain your numerical grading."

The numerical grading was based on a partial list started by a professional audio reviewer that I read somewhere along the way. He was the person who first suggested the notion of a clock face using 12:00 as absolute neutral tonality.

Since reading that review and list, I have tried to add to it whenever possible.  But only if the reviewer makes a specific comparative remark about a brand or component that is already on the list.  For example, if the author compares the reviewed unit to a Boulder 2060 amp--on the list at 12:00--and says the reviewed unit is "slightly warmer," then I might extrapolate that the reviewed unit should be at 11:45 or 11:30. 

Do Michi M8 and Boulder 1160 play in the same league? Regardless of their tonality, is one a little more neutral, the other a little more lush, they have the same sound quality, or is the michi M8 weaker?

I have heard both of those amps in the same system. Michi delivers a lot for the money. I think some people who have never heard a Michi amp will "knowingly" relegate Michi to a lower status because it is a Rotel product. I'm always amazed at how much some folks know about a product without any actual experience.

I have auditioned Michi against  McIntosh and Classe products and much preferred the Michi-obviously a personal preference. The Michi could power a small city, is built like a tank and seems to be well engineered. I find it to be a bit warmer than the Boulder but nowhere near the McIntosh sound. I think its a bargain and a very good performer even if you don't consider price.

As much as I like the Michi, I don't think it is quite in the same league as the Boulder, which I think is an elite brand. The Boulder amp is about as close to dead neutral as you will find-it neither adds nor subtracts. Some might call this analytical, not sure I would. Very clean sound and a superb product. If you are looking to add warmth, not for you. If you are looking for neutral Boulder is an excellent choice and its "entry level" range gives you much of what you get from the superb but incredibly expensive higher ranges.

Just my thoughts, everyone hears differently.