Tube Preamp Reviews

I believe a lot of people would actually like to see a blind test like A. Hourst suggests, so he's not the only one.
I, and probably many others would find it very interesting, and I'm not convinced it would necessarily turn out one way or the other. So, it would be nice to find out if there really are audible differences between two amps that measure the same :-).

Maybe you have already noticed that the blind test advocates usually ONLY ask Fremer (or anybody else) to do blind tests with certain things.
As far as I know, nobody has ever asked him to do a blind test comparing ANY of the speakers he has ever owned to a pair of 200 dollar computer speakers or even to 1000 dollar KEF speakers. Nor do I see any requests for a blind test between a Lyra cartridge and a 50 dollar Audio Technica cartridge.
And why?
Because the objectivists already know that there are readily audible differences between most speakers and also many cartridges. As for cartridges, I've compared my own cart to 35 others, and the blind tests I have done, only with the ones that were the most similar, I passed. I even passed blind tests on some adjustments (overhang, stylus pressure, etc.) that I didn't expect to pass.
Even some of the very first ABX tests done in the late 70s and early 80s showed that speakers and volume levels were by far the easiest categories to hear a difference. On that note, recently I successfully ABX'ed 0.2 dB volume difference on actual music with 15 out of 16 correct (the test I'm the most proud of).
So, the objectivists are usually (not always, as some objectivists really are obnoxious and OCD) asking for blind tests of more controversial topics.
Personally, I think that blind tests will/should reveal differences between certain amps, but some objectivists disagree, and amps seem to be the category that splits the crowd a lot. But even hardcore objectivist Arny Krueger said in "The great debate" in 2005 that he has successfully heard differences between power amps in blind tests.
Then there are categories where it's simply highly unlikely that people can hear a difference, because nobody else has done that so far in a properly conducted blind test. This category includes hi-res vs. the same material down-sampled to CD quality, analog tape vs. a properly digitized copy, and cables. However, some cables are not transparent in the sense that they can be faulty or have certain properties (impedance, etc.) that will alter the sound. Someone at Hydrogen Audio did successfully ABX speaker cables, and a measurement showed quite a different frequency response for the two pairs. Also, Audio Critic showed in the early 90s that certain cables rolled off prematurely or had a spike in the treble, and some of this is audible, and some people buy these cables for exactly those audible properties.
And lastly there's the category of products that simply cannot produce any audible difference based on the currently known laws of physics. This includes expensive power cords and tiny acoustic products by Synergistic Research. Although some people report differences, so far no properly conducted blind tests have shown any difference – quite the opposite.
It's also worth noting that Synergistic Research, Nordost and Audioquest have been shown to do fraudulent demos, where they changed the volume level and used other tricks to "show" an obvious difference that everybody could hear. Obviously, they do this as their products simply don't produce a difference.
This is why we need blind tests. Blind tests are the kryptonite for the golden eared, but also their bragging rights if they pass (I've passed many and failed many) :-).