Hiss sound with Fiio E7+E9 Combo

Hmm, do you hear hiss only when changing the volume or is it constant?  Also, which headphone socket(if that's the correct term) do you have your Denons plugged into?  The 3.5mm or the 6.3mm?

Okay, one more question, is your E9 set on low or high gain?

This is completely normal in amplifiers. The only solution is to use higher impedance headphones. The Denon D2000 is only 25 ohms. Try something like the Sennheiser HD650 (300 ohms) and you should hear a big improvement.

I don't get any hiss with a Little Dot MK2.  Any hiss I do hear is being amplified from the recording.  Some recordings have 'air' in it that is actually picked up when amplified through revealing headphones-- especially ones with treble extension.

FWIW - I just tried my AD700 and SRH840s - both sockets - and can't hear any hiss (even at full volume - music paused of course).

I had D2000 before, no hiss in high nor low gain (both 3.5and 6.3mm)

Even with my D5000 now, the E7+E9 combo still sound very clean

May be a defective item

Edited by 021311 - 8/9/11 at 10:18pm

I have no hiss with any headphones of any impedance.  Check your e7 to e9 connection (make and break it a couple times if you have to) and switch out cables.  Use a different source.  Plug the e7 in through the line in. You should be able to isolate the issue fairly easily.

Mine had hissing at about 50% and up from my desktop through USB, but no hissing from a line-out from a Fuze at max volume with the HD 650.