A wall of screaming stacks pumped directly into your brain! The Rockman Metal Ace is a high-quality, low-priced headphone amp that offers built-in compression, volume control, and auxiliary stereo input/output. Use it to jam along with your favorite bands. Killer distortion with switchable gain. Sound so heavy, many a serious metal monster have used this thing as a studio direct box or a distortion unit in front of their amps.