Features:

Balance VS Unbalance
HPA-3B is a new member of the M-Stage series headphone amplifier, who is the first one full-balance design of the headphone amplifier, both supports single-ended output and differential output, maximizing the performance of the headphones.

THD-N: <0.0003%
Full-band of THD+N less thant 0.0003%, SNR up to -114dB, bandwidth not les than 140K at -3dB gain, 0.4 ohms, three gain level options to fit for the different impedance and sensitivity headphone, all of these excellence performance improvements to born the brand new HPA-3B!

You Can Have It Both Ways
HPA-3B is both a balance headphone amplifier and a single-ended headphone amplifier, can input the single-ended signal via accessary XLR converter.

Brand New
Excellent structural design to quickly dissipate the heat of power tube via the shell, full symmetric circuit layout, fully differential signal path amplification, driver stage is the precision constant current source, the precision quadruple potentiometer volume control, so that the HPA-3B has better dynamic range and details than a single-ened headphone amplifier.

Best Selection Best Match
The Alps customizes model of volume potentiometer, Wima and Nichicon audio grade capacitors, Noratel toroidal transformer, precision non-inductive resistance, each carefully selected components make HPA-3B not only presents the perfect sound, but also a more stable and reliable.

Specification

Balance Headphone Output
SNR: >-114dB A-Weighting
THD+N: <0.0003% at 300ohms 135mW 1kHz A-Weighting
Frequency Response: 20Hz-20kHz(+0dB/-0.05dB)
Output Impedance: 0.6ohms
Output Power: 3800mW at 33ohms / 1500mW at 300ohms / 800mW at 600ohms at THD+N=0.01%

SE Headphone Output
SNR: >-108dB A-Weighting
THD+N: <0.0004% at 300ohms 325mW 1kHz A-Weighting
Frequency Response: 20Hz-20kHz(+0.03dB/-0.1dB)
Output Impedance: 0.4ohms
Output Power: 2100mW at 33ohms / 430mW at 300ohms / 220mW at 600ohms at THD+N=0.01%

Gain Control
Gain: 5=5dB 10=10dB 20=20dB

Power
Power Voltage: 230V position is fit for AC220V-240V 50/60Hz
115V position is fit for AC100V-120V 50/60Hz
Power Consumption: <25W
Fuse: AC250V/500mA 5x20mm

Others
Dimension: 285×142×49mm L×W×H(Including the protruding part) 
Weight: 1.7kg

Package
1 x M-Stage HPA-3B Unit
1 x Power Cord
2x XLR-RCA Adapter
1 x User Manual Disk