Like the title says and what do you think of the "awesome amp"?

Im using one of the most sensitive and lowest impendance iems on the market (ie 80) and i get a noticable background hiss (Before I followed the guide to get maxx audio installed properly it was too much but now its tolerable, thanks to everyone posting about that particular solution. The only way to control impendance/gain setting is through maxx audio so if youre getting crazy hiss with low impendance headphones its probably because the default gain setting is high without maxx audio installed.).

Money is no object within reason when it comes to sound quality for me. Only reason i bought htc one was the sound quality through headphones. I always have the best available source files for my music, never anything below 320 kps mp3s and thats rare its almost always flac.
I own a cambridge magic + for my speaker setup.

Im considering buying Shure SRH940-E or hd 650 because i dont want a whole string of dacs and amps, I want something that works well with the built in amp wich i can hear is more than enough in clarity except for the hiss. Im leaning towards Shure SRH940-E because detail is everything to me but its so clinical it enhances all faults in the source from what ive read, so im wondering if hd 650 might be a better choice if the built in amp has that hiss regardless of impendance/sensitivity.

Anyone using either of those phones?

Im not going to buy hd 800 because that price class is beyond reason for next to no gain imo. Its to use with this laptop without a string of extra gear, thats the point.

I think the headphone amp is great for what it is ( more separation and clarity than any other built in solution ive heard even on bad recordings like youtube) except for the bad gain settings/hiss.