[RRod]

Interesting. I wonder much 0.1dB can change the tonality of things. I'm big into turntables. I'm pretty sure my preamp applies the RIAA curve with an accuracy of about ±0.2dB. However, even expensive stuff like McIntosh is only as good ±0.3dB. If 0.1dB makes a difference in an ABX test would a 0.1dB difference in frequency response make a difference in audibility on a phono preamp? Everywhere else I ask the question people just tell me "specs don't tell the whole story" and to "trust my ears".

As bigshot said, who knows What else they messed up in the test. I am probably mistaken in assuming it's ONLY 0.1dB of gain that is causing audibility. Whether the FR variation among different pre-amps is audible comes down to particulars. Assuming a well-tuned system, -0.3dB at a given set of frequencies will be harder to detect than -0.3dB at ALL frequencies, but of course volume matching actually cures the latter…