It's not so much limited, its just that I'm not too sure if I'm willing to pay for an AP+DAC that costs more than any pairs of headphones I purchased. THe e7+e9 barely breaks that limit. How could you compare the two amps together? If it's a worthy investment for the Nuforce (Icon HD, I don't need the pre amp) I will consider it.
Hey soul, have you tried the Fiio E7+E9 combo? I can't decide what my first amp will be.
If you have a limited budget, go for Fiio E7+E9 but if you have a bigger one, absolutely Nuforce Icon HDP. But if I were you I will choose Nuforce HDP. Though I also love my E9.