The Cute Beyond is optimized for a wide range of load impedances, and is suitable to most headphones from the Etymotic ER4P (27 ohm) to the AKG K240DF (600 ohm). This high bandwidth, extreme low noise design (lower than -107db) yields greater than 105 dB of dynamic range and exceeds the capabilities of human hearing, ensuring it can handle even the most difficult headphones. Two gain settings, selectable by a rear panel switch, allow for quick and easy optimization for high or low efficiency headphones. To satisfy the tweakers among us the Cute features user changeable opamps and a Shunt/Series type input volume control to suit different tastes. Other features include short circuit and thermal protection. No cheap plastic here! The Cute BEYOND is manufactured with a solid aluminum chassis and features an anodized aluminum face plate in you choice of red, blue, violet, or gray. The volume knob is also machined from solid aluminum for a high quality look and feel.