How will he make sure of that?
He requires a perfect 24 out of 24 score for identification of the amp in question. This is far more than requiring statistically signifigant evidence (say, for example, if the subject could identify one amp over another correctly 65% of the time, which would indeed indicate the subjective differences exist and disprove his hypothesis...but it is his $10K, so I can see why he is so restrictive. To get the money, you have to prove absolutely that you can pick the better sounding amp each and every time.)
This really makes me think some folks have too much time on their hands. Look, this whole hobby is about what connects you to the music in the most engaging and entertaining way. For some, that may mean specsmanship and gear weiner wagging. Their goal is absolute true to source replication of the musical waveform. For others, it is recreating the most vivid and believable recreation of a musical event. This latter sect often use gear which specs horribly, but somehow creates a more engaging musical experience where the gear gets out of the way and lets the music through.
Fact is, hearing is subjective, and 'good sound' is purely in the mind of the observer. Also, unless your room and system is an exact replication of the mixing booth or live venue, an exact recreation based on pure measureable metrics (which I propose do not fully encompass the qualities which we subjectively identify as 'good sound') is simply impossible. I suppose it is much easier to convince oneself that their mega-buck, mega-watt systems are superior simply because they spent so much to get there (such systems typically are quite impressive, after all).
Given the unrealistically high bar set by this challenge, I doubt I could identify my amps 100% of the time, but I strongly suspect I could get a statistically signifigant number of correct identifications. Although I have not been stringent re level matching and such, I have tried numerous different amps in my system without making any other changes, and the differences are quite distinctive. I've tried several solid state amps, all of which support the 'no audible difference' hypothesis; these include a Yamaha receiver (RX396), a couple NAD amps (and old 2100 and a new C372), an Emotiva (RPA-1), and an old Crown pro-audio amp rated at something like 500w rms. Aside from the Yamaha with it's much more modest power reserves, these all sounded pretty much indistinguishable.
Recently, I took the plunge into tubes. Now, I know that these new amps are reactive to the speaker load, don't have the ruler-flat freq response (although they are +/-1.5db from 23hz-22khz, not bad for a tube amp), are severely power limited, and as single ended designs exhibit prominent 2nd order harmonics when approaching their limits. I fully understand the on-paper limitations to such gear. However, the listening experience is so much more enjoyable, and the sonic qualities seem so superior to my ears, I can't deny it.
The ss amps all sound extremely powerful, capable of raising the roof without strain at all. Unfortunately, they only seem to come alive during listening sessions at or above 100db, and I just don't listen that loud except for the briefest of periods. Also, the soundstage is notably blurred, with individual instruments not quite localizable in the image, with the image-depth contained in a shallow range and localized between the speakers. I would never have thought that these amps lacked for anything performance wise, at least until I tried the SETs.
The tube amps, on the other hand, sound rich and full at any volume setting, from the threshold of audibility to their limits (which, in my room and with my speakers, allows dynamic peaks in the high 90's/low 100 db range, plenty for all but rockin' house party levels). Sure, compared to the ss amps, it is like viewing through rose tinted glasses, but despite the coloration, the image is far more focused, deep, and revealing of the recording space. Despite the coloration, these tube amps really get out of the way of the music and let you get absorbed into the performance. They recreate the musical event in a far more compelling way; even in complex orchestral numbers, you can precisely locate individual instruments, and their tone is far more realistic, to the point that it sounds like the musicians are present in the room. The solid state amps just fail to do this; with the tube amps, the 'speaker disappearing act' is typical.
As an example, I was recently listening to an old Widespread Panic CD which is particularly harsh on most ss amplified systems. Specifically, the album is Space Wrangler, and it is characterized by quite a bit of chimes and other high freq percussion instruments. The ss amps without fail blur this high frequency info, resulting in an edgy, fatiguing listening session. With the tube amps, each and every single strike of the chimes and cymbals is noticeably more distinct and well defined, and the kit is noticably placed deeper in the soundstage. Likewise, the violin/viola on this album is screechy and thin when played on the ss amps, where the tubes produce a realistic woody reverberance and you can practially smell the rosin flaking off the bow. Vocals are more distinct, clear, focused, and well rounded. Keep in mind that aside from the amp swap, the room/system/speaker placement did not change. These qualities, even if they are an aberration from a perfectly replicated signal, result in music that pulls you in. It is virtually impossible to avoid an emotional connection with the music with these tube amps. I personally will take the added realism, clarity, and vividness of the tubes, even with the rose colored lenses, over the harsh bright light of solid state amplification.*
Many, particularly the regulars here at AH, cannot seem to wrap their heads around the fact that a sub $500 SET tube amp kit can sonically crush just about any ss amp costing thousands of dollars. I suspect that if such amps were used in this challenge, a statistically significant number of listeners would be able to identify them when compared to ss amps (although I doubt anyone would meet the 100% correct criteria of the challenge), and I also suspect the subjects would greatly prefer their sound.
*I've recently had the luxury to listen to a Pass/First Watt ss amp, which is class A, and it exhibited clarity and depth of field of my tube amps, and has a flatter and much more extended freq response. Of course they cost >$3K. My modest amps cost a tiny fraction of that and get me 95% of the performance. I've never heard any class AB amp that possesses the imaging prowess of pure class A amps, ss or tubed.
