I listen heavily to classical and rock and have a hard time using any headphones without using the amp. The amp provides the Headroom 'process' that provides better depth to the sound which lets you listen for longer without getting tired. In addition it provides an extremely straight sound where you can hear everything you are meant to hear without one frequency overpowering another. I have used them with Etymotic ER-4S headphones as well as Sennheiser HD600 headphones. The amp is great with either, but the sound with the Etymotic's will blow you away.



Recommended: Yes

Amount Paid (US$): 600