I love the sound of my HeadAmp GS-1 with the AKG701s. I'm feeding it with the output from a Benchmark DAC1-USB, and the combination is exquisite (to my ears, at least). Opinions on amps do vary, as expected, and I've seen folks on this forum who do not share my opinion about the GS-1 -- most comments being that the GS-1 may be too dry and "transparent" for the 701s, which some say need to be "warmed up" a bit. I don't share that opinion. I do feel that the 701s are somewhat fussy with regard to amp synergy, and though my experience is limited, I have also used the 701s with the DAC1-USB's own headamp as well as a HeadRoom "Maxed-out" Desktop, neither of which sound nearly as good as the GS-1.