Just picked up a nice little Ray Samuels 'The Predator' portable amp/dac today. Now just need a cord. Anyone care to comment on the best way to go? The amp has USB micro on the back and 1/8" input on the front. I will be coming out of my MacBook Air on the desk top primarily. USB to micro USB best? Or just go 1/8" headphone jack on the Mac out to the 1/8" input?