Yes I am definitely confused. I know you are not confused and many here sounded like they are not.
So you are saying if level matched, no one will be able to tell apart say a dac with tube output with heavy distortion over a SOTA dac with minimal distortion.
I own a Schiit Freya tube preamp and a Benchmark LA4, if I level matched them, I will not be able tell it apart?
Sorry for W.O.T. but this is complex.
Only you can tell .... but level matching and knowing which pre-amp is playing will still make you hear differences. That's simply how the brain works... bias and this cannot be 'shut down' by knowing there is bias as this bias works at an unconscious level.
You would need to level match within 0.1dB so within 1% (both channels, chances are there is channel imbalance in the Schiit).
Then someone else, or a nifty random device, needs to switch the output signal to the power amp.
You must regulate the volume on the DAC or software. Cannot touch the amp vol controls during the test.
The one doing the switching (at your request) is to randomly (flipping a coin or using some app that gives a random 1 or 0) disconnect (or switch) the output connectors of the preamp and insert the cable from the chosen pre.
This must be done in such a way there can't be any 'tells' say different RCA cords that make a different 'sound' or move the power amp more or less depending on how easy the connector goes in or the time it takes to reinsert or grab another cable and or sounds like laying down a cable and grabbing another one.
He/she/whatever must make a note (which you aren't allowed to see) what is connected and must not give 'secret' clues such as a smile or you seeing if he grabs a different cable or you seeing a cable move etc.
You must 'guess' or 'hear' the difference and can take your time, adjust volume, skip music etc. Write down what you think you are listening to and maybe even add a 'confidence level' (how sure you are).
Do at least 20 'switches' (they may be 5x the same amp in a row) and compare notes afterwards.
Can you really hear differences when not having any clues as to what is connected ? This is the key thing. As you can see doing a proper controlled blind test (measured within 1%, not knowing what is playing (the blind part), and statistical relevance) is very hard to do. In fact no one would really go through with it but it will reveal the truth.
That truth might be: you can hear differences with high confidence or you cannot hear differences with high confidence.
That truth will certainly differ from the 'I know what is playing' truth.
And so you know I actually did tests like this decades ago and came to my conclusions.
I won't these days as it is pointless with modern gear unless it is really performing that bad that is makes sense to be audible different.
I can still 'hear' differences between gear and even hear differences when there aren't any in reality.
Whenever I am in doubt I 'investigate' (when it is important to really know) or when it does not matter (just for enjoyment) I take it as it is and use what I prefer for whatever reason.
If I had both and I had a preference for one or one is more suited for a certain application (easier to use for instance) I would use whatever my preference was at that moment for the reasons I had then. All perfectly fine.
However, if I wanted to go 'on record' and make hard statements I would do something like described above (but would use a random switcher) to present my case using a record of that test (with measurements) and if I had to inform the world what my abilities were I would do it a second time and film it all. Should I be writing a paper about it I would have to repeat the test with other people and maybe other music and even other amps and transducers. They would have to be 'interested' people in that test and not random students.
That would take me at least several months to test. Then and only then we can know if they can be discerned.
On top of that... the folks that showed they could distinguish (when a percentage seemed to be able to) I would test again to see if it wasn't a fluke.
There you have the difficulties of asking someone to provide proof in the form of a blind test. Really... no owner is (willing) to go through all that.
This means that either 'we' have to accept the 'comparison/test' was done correctly and believe that the made 'audibility claims' were valid, often with the comment... he/she/whatever also heard the same
or 'we' can accept the fact that the person in question 'perceived' something and we don't know why and under what circumstances but chances are the 'comparison/test' was not done according to the correct protocol (which is extremely likely).
Then 'we' can only assume there is no malcontent and have to believe what the person is saying is really true while also assuming one of the used equipment was performing correctly and not defective or not really suited for the application (driving or loading connected gear improperly)
Then we would have to tell that person that he (probably) did not test correctly, despite the insurance that they did, that they should test again and explain. That person would then feel he is not taken seriously (personally) when all that is asked is for proper controls, and not piss that person off.
Yep... no winners in this circle unless 'we' believe that person or the person is interested and actually performs such a test. A few times some readers actually went through the hassle.
The rest leaves pissed off they are not believe and spreading their knowledge about those stupid ASR minions having no ears, look at graphs only, don't listen to music nor enjoy it and listen to sweeps. Not pissing them off is virtually impossible.
This means... IF you really want to know you must test acc. to protocol. Don't believe swapping out components is enough to gauge if they sound different. All you will get is that you will have a preference (or might not) but can't be sure IF what you heard is not due to another 'aspect' and truly 'technical performance' related.
cen.acs.org
