Creek OBH-11 Headphone Amplifier (Black) Best suited for low impedance headphones - 30-300 ohms Features one pair of stereo RCA input jacks on rear panel, and a 24V - 150mA DC power jack, for connection to included power supply adapter Single 1/4 stereo headphone jack on front panel Dimensions - 2H x 4W x 4D; weighs 12 ounces