The hiss is not the fault of the Livewires. They're just really sensitive.
This hiss is pronounced only when connected to the headphone out of the iPod Nano 1st gen, iPod 4 gen and iriver H120. There's some hiss with the 1st gen iPod shuffle. The iPod 4 gen is the worst - loud hiss and it buzzes when the hard drive spins. This is the price to pay for sensitive IEMS.
I've connected the iriver H120 via optical digital out to iBasso D1, and there's no hiss without turning the dial past 2 o'clock. Obviously I wasn't listening to anything then, or I'd be deaf by now. The problem I'm having with the iBasso D1 is that it's too loud for the Livewires. To avoid channel imbalance, I have to turn the pot to where it's a little too loud for my taste (between 8 and 9 o'clock).
Connecting the Livewires to the line OUT of the H120, there is significantly less hiss even at the same perceived volume of the headphone out. So, it really pays to have a good amp.
With either iPod -> ALO Cryo Silver LOD -> RSA Tomahawk (low gain setting), there's barely a perceptible hiss. I probably won't use the Livewires on the 4 gen iPod without the Tomahawk.
I really wish I could spend more time with the Livewires. Busy right now, but will post more about my experience later.