the "multi tube per rail" detail smearing problem exists in solid state as well.
the ’sweetest’ sound of any given amplifier line up is the single pair output devices or even single ended. A 20 year long living example was always the Bryston 4b vs the 3b vs the 2b. Essentially the circuit between them was the same, but the 2b was always the sweetest of the bunch. Only one pair of output devices per channel on that one.
More interesting ways of trying to solve the problem are amplifiers that use the same output device (regarding transistor designs - being more rare in that arena), which you’ll have to look closely at the specs or product information to find. The BHK series of amps from PS audio are done that way, all the way down to the cheap (DIY-rebuilds) favorite (this week’s flavor) of the Realistic SA-1000 integrated amplifier.
Execution of the given circuit also counts, obviously. There is so much overlap not just in amps but the rest of the given system, that this all important point of understanding you are aiming at - can be difficult to discern. Or even hold onto, in the face of the onslaught from the rest of the sometimes forcefully opinionated audio world that may be out there.
Usually, if one is asking this particular question, then one is beginning to knock down the correct doors, regarding one’s search for the best sounding gear that is also more correctly reproducing what the hear expects to hear, with a music signal.
Keep asking and looking for the sonic tonic or solution to this particular problem and your ears will eventually hone in on the correct parameters for proper reproduction of the most critical of the signal components -regarding how the ear works. Your mind and ears will learn as a pair due to correct focus and the expected learning from such a path.
Congratulations, you are walking down the correct road with the correct questions. You are in the act of building a stable reference of discernment. Your ears and mind -working together- to put yourself in front of the gear you might think embodies these given critical aspects... and then learning from what you hear..learning in that all important way..the way of --correct context/pairing of question and answer.
This will lead to learned discernment of this fundamental point being applied to the rest of the distortion problems and the sussing out of those as well. What you first need to do is to learn, with your ear/brain..this all important micro signal differential..and it will lead you successfully though the rest, over time.
To help relate on how important this issue is, how germane to the scenario and audio scene it is....I'd say it is one of the biggest quandaries in perfectionist audio amplifier design that existed at the beginning and still exists today.
