I just got a pair of HE-400i's that I ordered. I'm amazed by the amount of detail I can hear (a lot more than my DT-880s), but I've noticed that there is a sort of harshness to the vocals (and to the treble in general). Is this normal? I'm driving them with the DACPort Slim, so it's possible...

I just got a V1 Deluxe and plugged it in. I'm noticing that there is a high-pitched whine, even when the volume is turned all the way down (or the input isn't plugged in), and some crackling. It's pretty annoying, and mars the quality of an otherwise good amp. It appears that I can affect the...