The 3.5mm connector is not a problem (excepting cases where it's been damaged, has environmental crud on it, etc). The problem I've noticed (the hiss) is from

The 3.5mm connector is not a problem (excepting cases where it's been damaged, has environmental crud on it, etc). The problem I've noticed (the hiss) is from analog signals being generated either too far away from the connector, or without adequate shielding against ambient electronic noise. One thing that hasn't been discussed is that of power. Does the Lightning connector have the ability to pass enough current to the external DAC to drive large over-the-ear headphones and generate respectable bass without distortion? Or will the headphones require it's own battery (AAA or rechargeable)?