Short List of Amps I prefer over the Pass Labs XA25 or INT 25

Thanks for these notes.
Then you need a good DSP unit I guess. Perhaps in future a miracle can happen and digital speakers without any amplification will reproduce the sound. 

Meanwhile, another related practical question. Conrad Johnson preamplifiers have notably high thd I saw in specs of all the recent models et6 et7 and gat it is 0.15 (I was surprised to see this). I didn't have a chance to audition them but I assume they sound good.
Do they (do the higher order harmonics help)? I ask this question also because am considering to try one of these preamplifiers. Thanks

Then you need a good DSP unit I guess.

The DSP is built-in to such amps that have a direct digital input.

Conrad Johnson preamplifiers have notably high thd I saw in specs of all the recent models et6 et7 and gat it is 0.15 (I was surprised to see this). I didn't have a chance to audition them but I assume they sound good.
Do they (do the higher order harmonics help)?

There is a huge difference  between high THD and higher ordered harmonics! Higher ordered harmonics as distortion is bad and highly audible, but high THD might not be so bad, if the harmonic content is mostly lower orders (2nd, 3rd and 4th) as the ear is far less sensitive to them.

but high THD might not be so bad, if the harmonic content is mostly lower orders (2nd, 3rd and 4th) as the ear is far less sensitive to them.

Can we know, based on specs, whether THD referes to a lower or higher order harmonics? Is there another common parameter that refers to the higher order harmonics? I.e., is then a way to know about the "real" distortion (one we do not like) based on the specs? 

Actually no. I've been advocating for that for years, but the industry doesn't like the idea of a spec sheet that would actually tell you how the amp or preamp **sounds**.

too fuzzy. this is what  Jeff Fischel answered on my question on the distortion: 

"CONRAD-JOHNSON preamps are designed for optimal sonic performance , yet this is not always reflected in the specifications of distortion." 

well, we know CJ amps and preams sound well,where from comes this high distortion, or can it be good high distortion or CJ amps sound good despite high distortion (or because of that)? 

i have three alternatives for a preamp for my Cherry Megaschino
(now I am using $650 class A SS Nuprime HPA 9 headphone amp/pre which is not really bad, still might be worth to look for a replacement) : 

Pass Labs XP-12
Conrad Johnson ET6, and
Conrad Johnson ET7 

all of them have some promo, Pass is a demo unit. 
Did some of you guys compare XP-12 with a CJ prse, or ET6 with ET7 
(ET7 costs double of ET6!)?