what's the point?

I have to confess that I found the information in the link posted by to OP and the related article interesting. It tends to substantiate my own experience. If two amps have a flat frequency response between 20Hz and 20KHz and provide ample non-clipping power output to the speakers  (e.g. 300 Watt @ 4 Ohm in my case), then a listener will have a very hard time in discerning a difference between them under the same testing conditions, no matter how "golden" your ears may be.

I have some hearing loss but could immediately tell the difference in my new Bryson 14b3 and the 14sst it replaced. Next question please. 

According to this, all amps that are played below clipping sound the same (indiscernible).

Obviously the statement is false.

It presumes that all amps have the same amount of feedback (they don't) and further that the feedback renders them a perfect voltage source. It doesn't.


The differences we hear between amps has mostly to do with distortion and to a far lessor degree in the case of zero feedback tube amps (which have a high output impedance) frequency response errors. The ear tends to favor tonality induced by distortion and so if the amp has inaudible distortion (small amounts of lower orders being the only kind that might be considered 'inaudible') it will appear to be quite neutral despite the FR errors. This is due in no small part to the simple fact that loudspeakers without FR errors don't exist; they tend to be the source of the most FR errors in any system.

Back in the 1970s and clear into the 21st century, no-one made an amplifier that was able to employ enough feedback (due to poor gain bandwidth product) such that higher ordered harmonics were rendered inaudible. In a nutshell this is why solid state amps (and to a lessor degree, tube amps with feedback) tend to sound bright despite being flat frequency response on the bench.

The hubris involved with the statement in the linked article of OP is really off the charts, made by someone who clearly had no clue of what they were writing about.