For sale MASS KOBO 428 amplifier. Purchased new from JABEN. With box and still under warranty. Perfect, without even a slight scratch or sign of wear.
I am selling for inactivity.

<Specifications>
(Batt. 6V or USB 5V)

1)Model: Full-Balanced Portable Stereo headphone amplifier
2)Input: φ4.4 TRRS x 1 (balanced or unbalanced)
3)Output: model424 XLR-4Pin model428 4.4 TRRS (balanced) , φ3.5 TRS (unbalanced)
4)Maximum Input Level: +16dBm (balanced), +10dBm (unbalanced) 5)Maximum Output Level (P-P): 7 V (balanced), 3.5V (unbalanced) (with 32Ω loaded, 1kHz, THD+N 0.5%) (RMS): 2.3V (balanced) , 1.2 V (unbalanced) (with 32Ω loaded, 1kHz, THD+N 0.5%)
6)Maximum Output without Distortion: 165mW (balanced), 45mW (unbalanced) (with 32Ω load, 1kHz, THD+N 0.5%)
7)Frequency Characteristics: 20Hz - 20kHz (-1dB)
8)Noise Level: Less than 40μV (in the minimum volume position, 32Ω loaded) Less than 150μV (in the maximum volume position, 32Ω loaded) 9)Power Supply: AA Alkaline or rechargeable battery x 4 External Power Supply: Micro USB +5v
10)Weight:
Model428 440g (with batteries), 382g (without batteries)