Good, but...
I'd been looking for a headphone amp for some while to support my iPod. While I have a lot of newer headphones and earbuds that the iPod has no trouble driving, my favourite headphones are an older set of Sennheisers that were designed to be driven by a hifi amp not a lower powered mp3 player. The NX1s seemed to fit all the requirements, so I purchased one.
So, the good bits. This is a high quality bit of kit. from build quality right down to the accessories and the package it comes in. When used alongside my iPod it detracts from the sound in no way that I can tell and adds a little power across the board. It's exceptionally easy to use; charge it up, connect and away you go.
The downside, from my perspective anyway, is that it adds very little power and output to what the iPod can manage with my old, harder to drive Sennheisers, and for that I have to admit I was rather disappointed.
So, if you are using newer easy to drive headphones this unit will add a little power and overall boost to your listening enjoyment. If you are looking to give some oomph to older harder to drive classic headphones, look elsewhere.
Verified purchase: YesCondition: New