Agree, just about any stereo sytem sounds good to excellent at low volume levels. I'm refering to less than 9 o'clock on the control. Now just after 9 o'clock on the contriol, this is point where any average sounding amp, begins to show its coloration/distortion.
As you crank the control even higher to say 11 o'oclock, this is where the coloration/distortion make for fatigue.
Same applies to pseakers as well.
So when testing equipment, don't listen to low/nor to loud. Too loud will overwhelm the senses and if you are not experienced in what is true fidelity , you may be misled.
I'm amazed at how poor some audiophiles senses are when it comes to high fidelity. When doing a comparison listening, try to be as objective as possible. Your mind should somehow make the hearing sense as an objective function.
I had a friend back in new orleans had a $$$$ system with a Audio Research 200 tube amp and pre, Cary 202, Talon speakers, and Mirage One speakers. Sounded aweful, I did not enjoy the sound one bit.
I imagined he thought his system sounded great.
btw since he had the power, he use to listen loud, which made it worse.
Big money does not ever equal great sound. And never ever forget that.
Paul