high-end headphone amps

Can a portable amplifier improve an iPod's sound?

I've written about better-than-iPod-sounding music players before, but this is my first portable headphone amplifier review. The Todd The Vinyl Junkie Portable Slim amplifier ($349) really works and will take the sound of an iPod, or any portable player, to the next level. The amp's sleek chassis (4.2x2.7x0.4 inches) is nearly the same size as an iPod Classic. It's built in Dallas, and the case comes from Canada.

The Slim's rechargeable lithium ion battery provides 15 hours of playback time. It recharges in about 2 hours from a USB port or a USB … Read more