DT440 is much better really don't bother

He's my friend actually.Good seller as well

I brought 688B from intresco while for 681 I got it from him instead.

It sounded best with an amp but that doesn't mean it will sound bad without one

But with bad DAC such as onboard soundcard will make the 668B sounds really bad due to fact that it's a monitoring headphone which will detect every flaw that the onboard has.