You can disagree all you like. However, unless you do a listening test under blind conditions, you will convince no one. Toole & Olive, as well as many others, have repeatedly shown that the results of audio gear listening tests are heavily skewed if the listener is aware of the identity of what items are being tested.
You must also include negative control tests of A-B comparisons, where the listener is presented with A-A or B-B comparisons. How often do listeners believe they hear differences when in fact there were none?
Each listener must be tested when two identical items are compared. In theory, they should all answer “NO, they’re not different”. But you cannot assume people can always tell when test items are identical. You can think of a Negative Control as a measure how many “false positive” answers there are. You must measure the amount of these false positive answers that each listener reports. The false positive percentage for each listener must be subtracted from the percentage of YES or NO answers that listener provides when there really were two different items being tested. If all listeners have a low average false positive rate, you would be in good position to make useful conclusions about the cable comparison results. If that average false positive rate is high, 50% for example, you could only conclude that listeners could not reliably report what they heard. No useful conclusions about the listening comparisons could be made.
This isn't about dishonesty. It's that no one is infallible. You can think of the Negative Control as a measure of the background noise in the test. It won’t be zero. Measure it and find out what it is.
None of this should be a surprise, as the necessity of blind comparison tests has long been known in comparison tests involving taste, smell, or other types of human sensory perception.
The first principle of scientific inquiry is that you must not fool yourself – and that you are the easiest person to fool. – Richard Feynman, Nobel Prize winner in physics
Sword, appreciate the answer. Yes, I do disagree and you're welcome to disagree with me too. I have no motivation to try to convince anyone of any conclusion other than gather more information for myself. Prior to me playing with op amp swapping, I'd already read the opinions of those who say it makes no difference and those who said otherwise.
It's because of that, I bought several amps and many different op-amps to test it out for myself. I can distinctly tell differences in sound stage between op amps, I can distinctly tell differences clarity and other characteristics.
For low budget IC amps, yes, for the most part they are neutral, and hard to distinguish between one another. For that reason I would not bother. When you get into discrete op amps or different higher priced ones, you can distinguish between clarity in leading edges, sound stage characteristics as well as others. Some of those sound characteristics can be explained by FR charts, but not everything.
Whether you agree or not, if an end user perceives a difference, and that difference is worth the expense, then that's their prerogative. No one said that you have to agree or do the same. If you don't hear it, then it's not worth it. My mother could care less if she listened to a song on a crappy phone speaker, than through a high end system. Not worth it for her.
Regardless of what type of listening test you do, we're talking about perceivable differences from the human ear. In this way, it's never going to be perfect - so trying to "science it" is not very productive in my opinion.
We all have different hearing ability. It also matters how "trained" your ears are. I'm not saying you need golden ears, but someone who is not trained to look for certain attributes may not notice them.
Even if you show the same painting of a house to 2 different people who have 20-20 vision and ask them to describe what they see, you may get different responses. They both may say a house. The person who has trained to analyze artwork may tell you much more - like the the name of the artist, based on the color palette used, or the style of brush strokes, etc. A noob would not make any of those inferences even though they are looking at the same image unless they were taught to do so.
Again, I don't care to convince anyone here, this if for my own peace of mind. Thus far I have not heard any convincing, logical, scientific arguments for what I am hearing - other than I am audio fool and this opamp swapping is BS. Very dismissive.
It's a complete logical fallacy to say if YOU can't measure it, then it's just subjective and it does not exist. It could mean (but not necessarily) that you just haven't discovered the right testing method to measure that characteristic. It could mean that existing testing methods are incomplete.
Think 3 blind men and an elephant.
I've yet to see a spec sheet of an op-amp show a "measurement" of a sound stage, but from my personal experience and it seems many others, they can discern a difference between the soundstages of op amps, clearly and consistently.
Are we all just fools? Or is it just easier to name call when we can't explain what does not fit into our own cognitive bias limit of knowledge.
