Weseixas, Timlub, thanks for your reaction and comments to Atmasphere and Mapman, they are coming from very close to what my take on the situation is.
What I hope to inject into this conversation is something that for me has been very intriguing and frustrating over many years. That, which all hard core tweakers know, is that fiddling with any and everything makes a difference, and my reaction has been, what the hell is going on ?? Agreed, the topology, or circuit type of the amplifier can make a big difference, but once you improve your amp, then you more clearly hear the effects of making changes to other components, and the impact of everything else becomes more significant. Hmmm... not sounding too good at the moment ... gee, I wonder if that fluorescent light outside in the garage is on or off?
The trouble is, that last sentence is NOT funny, because it's true! Again, everything matters, and why does it matter? Because all the little, little things alter the makeup of my "micro" distortion, and the ear/brain has no trouble, no trouble at all picking up the change. It may sound better or worse, but it will definitely sound different!
Distortion can be linear, that is, altering the frequency response and phase angles, or nonlinear, which is everything else. The latter is the "baddy", big time: my experience is that if you minimise nonlinear distortion then linear distortion becomes totally benign, and the ear/brain can dismiss it as irrelevant. I've had a very ordinary amplifier (Sony) with classic tone controls, and managed to get the overall system working extremely well; then wound the bass and treble fully up and down, and I couldn't hear anything happening to the sound! Why, because the ear/brain could reject those changes as being unimportant to the musical message, enough "good" information was coming out of the speakers to compensate for a change that would normally be very obvious.
Yes, feedback is somewhere in there. But there is correct feedback, and "bad" feedback! If feedback was inherently not good then no piece of recorded music could ever be made to sound good, since every recording device and studio is riddled with feedback design techniques and circuitry, going back to almost the very start of electronic recording.
The quip earlier about the light points to a key factor that people play around with: power supply quality, or maybe, maybe it's RFI!? The trouble is, it's all very messy, but it ALL has to be taken care of!
Why should one? Because, if you do, then the level of "nasty", NOT "nice", micro distortion is reduced to the level that the ear/brain says "Yes! I can now accept this as being a thrilling experience, I won't be fatigued no matter how long I listen, it's magic, it's real!". And the convincing soundstaging, etc, automatically follows ...
Frank
