SMSL SH9

*THXAAA-888 Headphone Amplfier with THX AAA Technology
*6 Watts into 16 Ohm,3 Watts into 32 Ohm Headphones with lowest THD+N
*0.1Hz to 500kHz(-3dB) Frequency Response 
*SNR>137dB
*THD<0.00006%
*Ultra-Compact Design, Perfect for Desktop Systems
*Balanced Stereo Headphone Output
*Balanced Stereo Line Input
*High Precision Resistors for Temperature Stability
*Pop-less Design with High-Quality Relays
*High precision and low noise 256 level relay volume control; In actual use, in order to make the volume more linear, the extra levels are shielded.
*2 Positions Switchable Gain Control
*Fully Protection with DC, Over-Voltage, Over-Current, Short-Circuit and  Thermal Protection on Headphone Amplifier
*High-Eficiency Ultra-Low-Noise Power Supply 
*1.9 inch LCD display.