Every time a new audio product comes out, so does its group of trolls.
And for DACs, first there was Zero, now there is Compass.
The truth will be out eventually like how it did for Zero. But for Compass it may be harder, because it is indeed a DAC of decent standards, and not many people own something like a Citypulse or better to break the myth.
People do not understand that the placebo effect still applies even when you can hear a difference. In fact it is even greater because you can hear a difference and hence think that there is no placebo effect and hence be showered in the joy of self-satisfaction.
Someone once said, the best way to test a new product *on your system* (note: system "synergy" plays a big part) is to get used to your old product again first and listen to it for one week, switch to the new product and listen to it for one week, then switch back to the old product again. This way, you can decide if you were happier switching from the old product to the new product or the other way round, hence deciding which is the better one.
I adopt a similar strategy when testing my gear, just that my duration is shorter at 1/2 to 2 days. But, it does make a difference. And that's how I found out I prefer Zhaolu D2.5A over Zhaolu D3, and how LM4562 has more "space" and "speed" over OPA-Earth, despite the fact that both were supposed to be more expensive upgrades.
And one way this method can be further improved upon, is to combine the effect of ABX testing. Listen to a 3rd, lousy device for the first duration (week or days), then get someone to hook up one of the device for you, swapping the device every test period. Or even better if you dare to take up the challenge of randomness - the person will not tell you when he swapped the devices, the test period between swapping of devices vary, and you have to detect the difference yourself. If you can't or guess the wrong answer, u fail.
Usually the ABX test won't go wrong however, if your ears are sharp enough to hear the difference to easily say that one is better than the other (unless you are a level high enough troll).
The hard part of carrying out the test (just the basic time-based version without the ABX) would be telling yourself that your old device is good and listen out for its goodness. This is super important, because sometimes, we just switch to a new product, our expectations get us to widen our ears, and we hear that small sparkling sound in the air and conclude that it is better. Little would we realize that the same sound is also found in the old devices that we thought wasn't there, because we never thoroughly listened to it.
Also, there's a need to draw a line between "what sounds better to you" and "what is actually better".
Hence an AB test is usually flawed. And unfortunately when people go other's place to compare a product or borrow it home, we usually end up doing an AB because there is usually little time or condition for a proper ABX test, less to say use the "test of time" to be more objective hence accurate. The way I see ABX tests carried out sometimes is so bad it defeats its purpose - Listen to A, listen to B, guess. There's like a 50% chance of getting it correct. And after you get it wrong, you shrug your shoulders. That's it. Then you continue going on thinking that the one you like is better. Wrong. People who do that do not understand what an ABX test is, and hence full of bullshit when they say they believe in ABX testing. And worse, this boosts their ego and placebo effect, because they'd be thinking "I did an ABX test, so there must be no placebo effect." Do you know that placebo effect can also affect an ABX test also btw? Remember that hearing something different does not always mean that it's better, and just hearing one thing better does not mean you're hearing everything better on the whole. And if you're hell bent on locating that something in order to pass your ABX test or increase your chance of passing from zero to 50% (you know which is which, but you don't know out of the two which is the one you'd like to be better), you're not doing the test properly either.
ABX test - Wikipedia entry
Either do 5 tests and get all correct, or 10 tests and get no more than two mistakes.
Are you scared now? Losing your confidence already?
Well, there ARE people out there who can get 5 out of 5 correct, even some of the people directly picked off the streets. But if you are scared, probably not you.
That's why, instead of listen to a whole CD of test tracks, playing a short part each time and carring out the ABX test for that short part is easier and more accurate. Of course, the final test of whole songs still needs to be carried out, since songs are about the whole thing, not just parts of it. And instead of listening out for one thing, listen for different things each time, jotting down which part you think is better for which DAC you think it is. Of course, do it more than 1 or 2 times, in case randomness screws the result. WIth a source switcher, it's super easy to do ABX test for more than 50 tries in a short amount of time if you're listening to just one small section of the song.
Or just save yourself the trouble and the risk of knowing that you cannot hear that well (aren't we all) and losing your reputation on the forums, go with the time test. It hasn't gone wrong for me. At least 3 times, I expected the preamp of the Zhaolu to make my sound better, at least three times I was surprised by the improvement when I switched from the preamp back to direct line-out after using the preamp for a few days. And I wonder why so many Zero users like to use variable out. (Oh yah, because they are trolls) Do note that each time when I switched to the preamp, I also noted an improvement, of better, tighter yet more lower-hitting and more linear bass response, and a more controlled sound on the whole. But without it gives a much better improvement. Hence I say that not every improvement is a good one.