Polosatik:...Just to make sure I'm clear, do you need more current or less for the PS1000? If it has low impedance, I would have thought that it needs lower level signal compared to a higher impedance headphone, no? So, following this logic, you an iPod should do (in theory) work better with it than a dedicated headphone amp. Or am I confusing things big time?
Hehe. Sorry for the confusion.
We are talking about Resistive Impedance, an opposing force to the AC in a circuit, in this case the audio signal. The lower the resistive load of the upstream component, in this case the transducer's coils, the more current the component will draw from the amplifier. This is the stumbling block of many amplifier designs as they can't provide the current, it's actually easier to design an amp to drive high impedance phones. So yes the PS1000s will demand more current then say a pair of Sennheiser HD650s at 300 Ohms.
Hope this clears it up for you!