I'm opening this thread because recently, I had a debate with stv014 over at Full-Size Headphones and we both had quite a heated exchange.
I'll apologize again to stv014 for my attitude, and I hope we can have a more civil discussion this time.
I'll make the intention of this thread clear and simple:
Would lack of power for an amp causes lack of bass, lack of soundstage, congested midrange, among... other audiophile claims regarding sound quality degradation?
So... is there any technical truth to that? Or is it all just placebo?
From my experience, I'd say "yes" without a doubt, and the way I look at it, it's both technical and placebo.
Now, my backup for this statement is simply this:
For an amp that lacks power to drive high impedance headphones, a lack of volume would be notable. Attempting to increase the volume past a certain threshold will clip the amp and causes distortions. That's the technical part. Also technical is the fact that some amps have undue colorations or distortions even at low volume either intentional (bass boosting) or unintentional (ground loop issues, EMI issues, impedance mismatch, etc...), and I think that plays into this myth as well.
Now... solely lack of volume, in my opinions, can cause this lack of bass, or lack of soundstage, because different people react to volume differently, and I think subjectively that even a slight volume difference (approx. 1dB) can cause quite a noticeable difference in perception of the sound. Maybe it is due to this difference in perception that we read about claims of "improved bass", "improved soundstage", etc... And this is the placebo part of my backup. However, I'm not placing too much confidence in the placebo part since many reviewers volume match their different amps before reviewing and still find this "difference", so I'd say it's mostly technical.