For whatever reason, there is a constant stream of people that like to "prove" that audio equipment all sounds the same. Only speakers sound different. Everything else, amps, cables, sources, all sound identical and this is easily proved with ABX testing. And these people keep proving it.
Here's the latest from a blog showing cables all sound the same:
http://consumerist.com/2008/03/do-coat-hangers-sound-as-good-monster-cables.html
My own theory is that ABX testing for audio is flawed. I don't know exactly why but the brain is obviously a very complex and sophisticated instrument. For whatever reason, ABX testing of audio equipment does not work IMO. My evidence is all anecdotal, but I do belive my own ears. I will give you an example. Before I got back into hifi years ago, I spent a decade owning a yamaha receiver and a pair of B&W speakers. The system was fine but I always thought it sounded bass light. One day I spoted a brand new NAD amp on ebay and purchased it. I had done zero reading on the NAD product and only new NAD from seeing the brand in stereo shops way back in the early 90s. I only new it was good brand I knew nothing about the signature of NAD products. After putting the NAD in place into a system that I had logged many hundreds of listening hours on, I immediately noticed the sound change. The most prominent change with the fuller bass. In fact, the bass was so much fuller that now I found the speakers to be somewhat too bass heavy on certain recordings. The exact same system that I felt was bass light for years. I change nothing but the amp, everything else was identical. I later learned that NAD was known for warm, bassy amps. That this was well known by the hifi community, but it was totally unknown to me. From this I conclude that the NAD amp did not sound identical to my old Yamaha amp. I believe this as a 100% fact. YET, the famous 1987 stereo review ABX test for amplifiers resulted in the panel failing to tell the difference between a Mark Levison solid state amp, a TUBE amp, and a cheap receiver. From this, and other ABX testing I have to conclude that ABX testing just doesn't work for audio gear. Either that, or my NAD experience is complete dillusion and it's just coincidence that I concluded it had more bass which ended up comporting with the overall hifi communities opinion. I refuse to believe that.
Here is an interesting article discussing this:
http://positive-feedback.com/Issue56/abx.htm
