How are you hearing no difference?

Listening with just your ears does eliminate the effect of psychoacoustics quite plenty if you are totally blind, and you ask the in-store consultant not to tell you which one of the several amps, or preamps, or players, or cables, etc...   in the lineup you are listening to... Particularly if the evaluation and results are repeated with consistency.

I found there can be significant differences in performance between components of same price ranging from freeby earpieces given out by airlines in flight or 50C RCA wires supplied with old boomboxes and cassette recorders, all the way upto multi thousand $$$ wiring and high end speakers... Same thing for other components in the audio chain.

While this has usually been the case, it has not been universally so... There have been some less than common cases where I have perceived little or no difference.

G.

Listening with just your ears does eliminate the effect of psychoacoustics quite plenty if you are totally blind ...

This is mistaken and a common misnomer. It is impossible to listen "with just your ears." Just as with vision, what we perceive is determined as much by our brain as it is by the physical hearing mechanism. There is simply no way to completely eliminate psychoacoustic phenomenona from a listening test. Those who completely reject scientific blind listening tests - and I’m not one of them - often cite that as a flaw in blind testing. It’s a valid point, but doesn’t completely discredit the value of such testing, imo.

... ask the in-store consultant not to tell you which one of the several amps, or preamps, or players, or cables, etc... in the lineup you are listening to ...

If you want a meaningful blind test, it has to be double-blind. And there’s more to it than that; to be scientific, you need to match levels, and you need to provide quick switching while also allowing the subject to listen for as long as he likes to each DUT, such as is provided in the abx protocol.

Conducting a valid, double-blind, scientific listening test is a tricky business. And even when properly conducted, it’s easy to misinterpret the results. For those reasons and others, I believe that audiophiles have very little practical use for blind listening tests.

Some very good points made here. I take care quite often to have a friend come help blind test; I also compare over time, and get my wife's "golden ears" opinion until she gets annoyed (humor).

I understand and agree that certain components will sound similar, especially DAC's. I've had to do some very careful listening to reveal the smallest of differences. On one occasion, the difference was so slight, it came down to a two second section where I could hear a difference of a faint bongo beat that DAC A presented with more percussion than DAC B (about the 6:56-58 mark on the song "Morning Mist" performed by Ahmad Jamal).

If you think that two components sound the same, then you need to keep listening until you hear the difference.

I'll admit that sometimes the differences can be so small they aren't worth mentioning or not meaningful enough. In the DAC comparison I described above, that difference had meaning to me, small as it was.