Pushin’ your iPhone 4/4S over the audiophile edge is the V-MODA VAMP‘s particular mission. It’s a Japanese-built precision headphone amplifier that comes in an aircraft-grade metal iPhone case with anti-shock silicone shields. Inside, the 150mW x 2 amplifier bypasses the iPhone’s wimpier internal amp to deliver…more power. The digital-to-analog converter assures precise sound translation  from the digital to your ears: PURE mode gives you the unadulterated goods; VQ adds a subtle 3D soundstage effect, with tighter bass and harder treble, for that enhanced listening experience. An optical output, tapped with an optional cable, turns your iPhone into a high-end signal source. The onboard lithium-ion battery provides up to 8 hours of play, and turns into a backup power source for your smartphone when you flip the switch. $650 and the audiophiliac iPhone is yours.