So I've been using the HD 598 for some months and I've been enjoying my music more than ever recently. I particularly like its realistic mids (absolutely love how it presents vocals), sparkly treble (though it can be a bit much once in a while) and of course, its massive soundstage. Meanwhile, the only caveats I have with the HD 598 is its definite lack of sub-bass and its slowness for certain genres. However, I do not have an amp nor a DAC as of now and I'm not especially worried since the HD 598 don't really need an amp or DAC.
In a headphone, I love beautiful midrange, (good with both female and male vocals) a fairly good soundstage at least, realistic timbre, (I prefer naturalness rather than neutral-ness) slightly sparkly treble, adequate speed and bass that is not overpowering but can slam well if needed.
So now that I've been looking for an upgrade, I came across two headphones that really caught my attention. The first was the HD 600 (which some have noted may only be a slight upgrade from the HD 598) which sounds much like my HD 598 with more subdued treble, slightly more sub-bass, a smaller soundstage and an even better midrange, as far as I can tell from my research. The second was the HE-400i, which is slated to sound like the child of the HE-400 and the HE-500. This caught my eye as it will probably have more speed, far better bass but I haven't tried an ortho yet, so who knows?
As far as amps go, again, I found two amps that were particularly eye-catching: the Matrix M-Stage and the iFi Micro iCAN. Both seem wonderful but with different strengths and weaknesses for my purposes with an amp. From my research, I believe the M-Stage will have slightly better soundstage, be able to drive more headphones and even has an included DAC, with a fee of $40. On the other hand, the iFi Micro iCAN interests me with its XBass (probably hugely beneficial with my HD 598's or the HD 600's, if I get them) and the 3D feature. (beneficial to both the HD 600 (which does not have the biggest soundstage) and the HE 400i (orthos are not well-known for their soundstage))
EDIT: I'm not really looking for a DAC, but thanks anyway!
Ultimately, I need help deciding what headphone and amp I want, so I need help from you guys. I would like new recommendations and impressions of the equipment above if you have the equipment as well as suggestions. Thank you for reading this far and thank you for helping in advance.
Sennheiser HD 600
iFi Micro iCAN
Edited by Garraty - 5/14/14 at 9:56pm