Niimbus US 5 Pro is the Ultimate Series Headphone Amplifier incl. 256 Step Relais. The completely redeveloped channel-separated and 100% analog amplifier circuit features hand-selected audiophile components and has been optimized for lowest noise and highest performance even on very low-impedance headphones. In conjunction with the oversized power supply and the associated high supply voltage you get an extremely detailed and tidy sound that plays in any setting and with any headphone absolutely relaxed and represents every nuance of the music.