The editor does a double-blind test to determine if amplifiers that are burned-in sound better than those just right out the box. The test that some didn't think about doing and others were afraid to do! The results indicate....come on, read the article. You may or may not agree but you will not fall asleep.

Over the years there has been a desire on this reviewer's part to make a unique, "first time it has been done" contribution to ascertaining the validity of claimed differences in sound between two components via blind-testing. Oh, I've done my share of testing via rigorously setup blind- testing procedures for determining if there are differences in sound-at the speakers-between cables, interconnects, amplifiers, preamps, CD players, etc. Alas, no one has paid attention. All of these comparisons have been done by the leading intellectuals of the "blind-testing" fraternity. These guys lead the way (with a deep respect from this writer for their contribution to sanity in the audio world) and anyone who follows is going to be ignored. That's the way of the world, especially the scientific/technical world. Everyone knows of Einstein but who knows of Ed Witten, huh? I accept the role as an outsider in the world of blind-testing, but like Theodore Kaluza (Who? You guessed it. He also followed Einstein!) I would like to be included in at least a historical footnote to blind-testing experiments.

Upon receiving two identical amplifiers (same manufacturer, same model) for review I suddenly realized that here was my opportunity to do something-via the blind-testing route-that had never been done before. To wit: To test the tweak claim that that an amplifier that has been burned-in has superior sound to an identical amplifier that is right out of the box.

From time immemorial tweaks have been claiming that, just like a fine wine, an amplifier needs a period of time to reach the ultimate peak in aural stimulation. I believe this old tweak tale got its start from the heyday of the tube amplifier when aging tubes had to constantly be rebiased for their always changing electrical parameters. Add to this the tweak reviewers incessant comparing of sound to a fine aged wine (Perhaps this group should call themselves oenaudiophiles!) and an oft stated analogy is accepted as fact by many in the audio world.

The tweak claims for amplifier aging have ranged from slight improvements in sound to improvements that border on the miraculous (Golly, it sounds like a different amplifier!) Unfortunately, no rigorous blind testing has ever been done to refute or confirm this belief. There are several reasons for this lack of scientific testing.

Most rational individuals write off the idea of amplifier aging as ludicrous. Why bother to test a claim that is the audio world's equivalent of testing the claim for the presence of a spaceship behind the Hale-Bopp comet! And performing such a test is the proverbial pain. You need two identical amplifiers. Then you have to burn in one of the amplifiers for a period of time while the second amplifier sits unused in the shipping box. After this period of aging you have to setup a blind-test comparison of the two amplifiers. All of this is dependent on borrowing two amplifiers from a manufacturer who is understanding enough to loan out a piece of saleable inventory for the sake of science.

Having two identical amplifiers in for review presented me with an opportunity for possibly becoming a short footnote in the historic annals of the audio world. I would join those great men who pioneered blind testing techniques in the audio world as a means to discover the audio truth. I immediately went into action.

One amplifier was placed into my listening system, playing music and test signals twenty-four hours a day for two weeks without letup. The amplifier was never turned off and its idling time was minimal. Prior to leaving for work every day I would choose a CD that was a test of frequency range and sound pressure level, place it in the CD player and remove the ear protection as I exited through the front door! To keep the house from being shaken to the ground (and to keep my neighbors from shaking me to death!) I configured my system for mono operation, connected the speakers 180 degrees out of phase and facing each other, resulting in minimal sound pressure levels while attaining maximum power levels. Upon my arrival home I would reconfigure the system to a normal stereo setup. At no time during a two week period was this amplifier ever turned off.

At the end of two weeks I conducted three single blind tests between the "aged" amplifier and the amplifier taken directly from the shipping box. The tests were taken over a period of slightly more than three hours and the results indicated no audible differences between the two amplifiers.

After the testing was completed I immediately shutoff the "unaged" amplifier but kept the aged amplifier on. For another two weeks I endured twice-a-day self-imposed flagellation of moving speakers and reconfiguring my system. The aged amplifier was always playing music or test signals and the unaged amplifier was never turned on. Two weeks later another round of three blind tests (three blind tests, three blind tests, see what they prove, they all ran ¼.! Sorry!) checking for audible differences between the two amplifiers. No audible differences. I continued on.

Another two weeks pass with the aged amplifier on continuously and the unaged amplifier turned off for six weeks, except for the time it was turned on for the duration of the two previous tests (approximately six hours). Same test. Same result. No audible differences.

So much for the old cliché that sacrifice is good for the soul. As of this writing I never want to do another blind test, but that's just speaking figuratively; rigorous blind-testing takes effort and time. And to hell with achieving a footnote in the annals of the blind testing discipline. I feel good doing something the tweaks wouldn't know how to do (or dare to do!) and the blind testing contingent wouldn't take the time and effort to do. Oh, I've saved the best for last.

One of the objections to blind testing by the tweak contingent is the (supposedly) degradation of the audio signal as it passes through the switch contacts in the switchbox. I don't think this argument is valid (As Peter Aczel notes, if the this is true then the function selector switch in a $20,000 preamp also degrades the sound, huh!) but unlike the blind testing fraternity I have taken the bull by the horns and proven the claim is bull. How? Simple! ,p> Identical setups (amplifier and preamp) were used, sharing a common CD player and speakers. These shared components were switched by moving cables from one system to another. No need for a switchbox when doing blind testing; something the blind testing fraternity has not fully explained; I don't think they have ever done a blind test sans the switchbox. Anyway, if you have objected to switchbox contacts causing possible sound degradation you'll now have to come up with another objection. And another. And another. And another. Which reminds me....

Coming to blind-testing somewhat later than most I realize that to argue "science" with zealots who believe in audio voodoo is rather fruitless. But....I am more than willing to have a sane and rational dialogue with those who wish to learn (I don't exempt myself!) or think they have credible evidence to prove me wrong or, more importantly, prove that double-blind testing is flawed. All of the individuals who contact me (testdetail@aol.com) will be given the courtesy of a reply and the list of equipment used and the test results. One caveat: Please don't use an argument based on what a dealer has told you or what you heard in a dealer showroom. If you can't understand why then there's no need to go any further. This is not a knock against dealers, they're the lifeblood of the audio world.... but you don't need a Ph.D. in psychology to realize that there's a vested interest in the dealer having you believe in differences!

Concluding on a humorous note and for extra credit: What popular three letter identifier for a switchbox have I not included in this review? Hints: It begins with an A and ends with an X. The middle letter is between A and C in the alphabet. The first correct answer submitted to this reviewer will earn the submitter an autographed copy of the original article, signed by the author.