One of the problems I believe I and others have, is though the arguments are convincing, I am not an electrical engineer, and I don't understand a lot of the things being said when you say I should level match with an "AC volt meter" that alone is hard to understand, I will have to research this. For me, In order to show myself that there is no value in high end amps, or that there is value in high end amps, I can't settle for just experience, that's why I want to AB test in some way, even if it's hackneyed, to get myself started in one direction or the other.
Another problem is testing myself seems to be prohibitively expensive / require experience. There are testers that claim differences in amps (Tyll from InnerFidelity) and testers that claim no difference in amps.
So I suppose i'm looking for some way to roughly test myself, without breaking a huge amount of bank (on testing equipment), if that makes sense. Even a rough test is satisfactory to me to start me on a path.
The best way to match levels is to measure the voltage across the speaker terminals while playing a test tone of 1000 hz or so. If you are using headphones, then you would measure the voltage at the cable connector. Set the meter to AC volts and put the probes on the connector. Very simple.
The major problem in audio is the existence of hearing bias. What happens is that people fall prey to expectation. They expect one unit to sound better than another because it is prettier, or more expensive or because some magazine writer said it does. Expectation bias is a self fulfilling prophecy. The only way to eliminate bias is to use the ABX test you are talking about. That means the listener has no idea which unit in a comparison is playing at any give time. Those audible differences caused by bias will disappear and those audible differences caused by the equipment will be real and confirmed. Because some writer says something sounds better than something else, unfortunately, means nothing at all. It may be true and it may not be but the writer's saying so is meaningless. Remember these folks are in the business of entertaining good prose is good entertainment. To know if one piece of gear has an audible difference from another, the only meaningful method is the blind ABX test.
All amplifiers have different measurements and it is easy to make measurements as long as you have the expensive equipment to do it. the problem is that not all differences in measurements are audible. Testing audibility is lot different than testing electrical performance because of hearing bias.
I got started with bias controlled testing when people began claiming that one digital cable "sounded better" than another. Since it is impossible that a competently made cable can change the values of the data, I knew this was nonsense. So I did some tests with my wife helping me to determine that I was right. One thing led to another and I got an audiophile group together to do a bunch of tests of nearly everything hifi. It is a very boring and very time consuming process and can't be done by oneself. It always requires help, otherwise you will know which unit is which. Personally, I would never go through it again. I learned from it to be sure but it was a hassle.
Edited by blades - 7/14/14 at 8:21am