I can tell you that the amplifier measure very great if you just put an ohm resistor and loop-back record it.
My measurement shows that DAC1 can do very great, all under 0.006% across frequency.
Blackcube is also very good, with DAC1 as source, it can drive with 32 or 100 ohm load ,while keeps the distortion rate under 0.001%.
But you can't expect such low distortion while driving an actual headphone unit or speaker unit.
Thus the distortion's small disturbance would be greater for the actually produced sound.
I've put out the result which I got from a microphone recorded result.
These kind of test could also be found on many speaker design forums. Though speaker's distortion is generally higher than headphones.
You can just find some microphone and recording equipment and do the test, rather than questioning actual data I've acquired.
Please don't keep bothering me with supposed lower specification, I know that all too well. Also I know it's indeed very well if you just loop it back.
But our ear is not made of circuit. We need the driver to move air.
I'm not denying the aim of lowering distortion. Actually I'm ENJOYING low distortion system.
But there are indeed some problems when it is not lowered pass some point.
BTW, you would see headphones performs quite differently in distortion factor. I use HE500 in my example because it's the lowest distortion headphone I got.
Most of my other headphone doesn't do as well. Example:
Phillip's cheap SHP2000:
btw, I don't have other flagship for testing since I got HE500, I've sold my DT990.
It would be a better comparison, though. I'm regretting the decision..... >_<
Edited by killkli - 3/4/12 at 9:41am