Talking about "sonic signatures" of amplifiers it is worthwhile to mention (and read about) Bob Carver and Bruno Putzeys.
The Carver Challenge | Stereophile.comBob Carver - Wikipedia"Carver caused a stir in the industry in the mid-1980s when he challenged two high-end audio magazines to give him any audio amplifier at any price, and he’d duplicate its sound in one of his lower cost (and usually much more powerful) designs. Two magazines accepted the challenge."
Bruno Putzeys: Head of the Class (D, That is) | Sound & Vision
6moons audio reviews: Acoustic Imagery Atsah
"Here's a quote from Bruno Putzeys
to get back on sonics: "It's always a dilemma whether an amp should be tuned for things like subjective bass control, sweet mids or not. One of the tricks a McIntosh does by design is to have a highish output impedance—because of the autoformer—which makes for a more liquid midrange sound and then to add a subjective sense of bass control by allowing a slight THD rise in the top end. When things like those are really tastefully balanced, such an amp can really make life hard on a 'straight wire' amp in a shootout. The signal actually comes out sounding nicer and more impressive than what went in. But on the other hand I think that to make the greatest number of people happy, one can't afford to give an amp a sound of its own because the number of new fans is probably immediately offset by the number of people who don't like that particular tuning. But it's tough to resist the occasional sonic touch-up. I can emulate the sound of pretty much any amp out there if I wanted. But so far I'm resisting. If ever I give in, it'll be obvious from the measurements and I hope someone calls me out on it. Anyhow that's why I decided I actually wanted the NC400 to have this unvarnished dead-pan delivery." His
white paper explains the details on the Ncore technology."
