Debating again which headphone amp to buy for my MacBook Air - I was thinking the iDSD Signature but splurged on something else that has put that level of spend on hold for a bit! Is the Hip Dac or Zen DAC a better option in the lower budgets? Portability not a concern as such, it'll stay with my Mac in its bag when not in use, otherwise on my desk or kitchen table for the most part. I'm struggling to see how they differ!
My end all/be all recommendation between the three would definitely be the Signature if you can hold off and save because it will give you the best of both worlds.
Between the two lower budget options, I would recommend the hip-dac so you have the portability option on battery power when you need it.
They are indeed very similar, but one is intended for the more desktop-based audience while the other gives you the option for whatever portability you need!