Richard Clark $10,000 Amplifier Challenge - Why Couldn't Anyone Pass this Test??


Any guesses? 
seanheis1
Notwithstanding my personally-held belief that high end stuff sounds better to me, I am willing to concede that some of the claimed superiority I (we) claim to hear in amplifiers or perhaps cables as well is due to the fact that the products we are attempting to A/B are not level matched to within a very tight tolerance.  There are just too many people that seem to fail these comparison tests when the products are level matched to ignore the statistic totally.  I think. 
Damping factor of the Macs is said to be 12.
What, if any, difference in frequency response of my speakers should I hear due to the varying impedance curve?
@dentdog with that much feedback, none at all. OTOH, the fact that the amp runs feedback means it will *sound* a little brighter on top due to added trace amounts of higher ordered harmonic distortion. The emphasis is added on account of on the bench no change in frequency response would be seen.
What Ralph said

https://benchmarkmedia.com/blogs/application_notes/power-amplifiers-the-importance-of-the-first-watt

This explains why my amps are designed as Class A to 2/3 power. The switching distortion at high output is insignificant compared to everything else. However at very low levels switching distortion is audible (at least on test signals) - so it is preferable to be in Class A at low levels (of less than 1/10 of a watt)

The article confirms to me that only carefully designed listening tests at very low levels will lead to audible differences between well designed high quality power amplifiers. Alternatively, stressful loads or extreme power requirements would audibly differentiate the amplifier with better performance.
You guys should Google the famous Sunshine Stereo  amp challenge. Owner of Sunshine Stereo couldn't  identify his  Pass Aleph 1.2 monos  between a Yamaha  integrated  in his own  system with his music.
There are of course many legitimate reasons why someone might not be able to hear the difference between two amplifiers or between anything else, like say cables. Unfortunately most of those reasons are not very complimentary.