Monoprice has Monolith Liquid Spark Headphone Amplifier by Alex Cavalli (33304) on sale for $59.99. Shipping is free.
Specs:Dimensions: 4.6″ x 3.7″ x 1.5″ (117 x 94 x 38 mm)Weight: 9.6 oz. (271g)Headphone Output: Unbalanced stereo 1/4″ TRS jackPreamp Output: Unbalanced stereo RCA jacksSignal-to-Noise Ratio: 108dB (ref. 1 Vrms input / 2 Vrms output @ 1kHz)Crosstalk: –73dB (ref. 1 Vrms input / 2 Vrms output @ 10kHz)Output Impedance: < 0.1 ohmsGain: +3dB or +6dBInput: Unbalanced stereo RCAOutput Protection: Delay and offset protection