Could someone describe the difference in sound I might get from a headphone amp like the Schiit Magni (apart from maximum volume, I don't need any more of that), compared to any of my current equipment? Or if the Magni is not an appreciable improvement, what sort of amp would be? Here is a list of the current equipment that I have available to me which I can use as a reference point:
Logitech Z-2300 headphone output (I believe it is amped because the level goes higher than the source, and it doesn't work when the system is not powered)
Creative Sound Blaster X-Fi Extreme Audio front panel headphone output (it's built into my P6N Diamond motherboard. The rear outputs are broken so I can only use the front)
iPad 2nd gen
PreSonus AudioBox USB
M-Audio Fast Track USB interface
My headphones are the Grado SR125i. I am aware that they are meant to be pretty good without an amp. I am trying to work out if I should hear any difference in any of my gear, and if upgrading anything could be worthwhile for me. I like the idea of having an amp, so I'm not concerned whether or not it is the most cost effective way of improving my listening experience as long as it has some positive and noticeable impact. I feel like there may be more/tighter bass when I use the Z-2300 as an amp to any of the other sources, but I can't be sure that I'm not just imagining that because of my expectations. I know the Z-2300's headphone output is probably an afterthought in their design so I'm hoping that a proper amp would have a similar effect, but better and more noticeable.