Product Review

Parameters:
Frequency response range: 0-100K-0.1dB
Gold-plated input / output socket
NE5532 OP chip (can be upgraded to better OP chips like BB or Muse)
Original nichicon electrolytic capacitor
TOP HiFi Original DALE resistors
Precision rings resistance
Battery: Lithium batteries, voltage: 12V, 1000mA
Charging time: 2-2.5 hours to charging full the battery
Working time: 4-4.5 hours
Output power: 450mW
SNR: 99dB
Suggest load impedance: 16-400Ω
Color: Black / Silver
Size(L*W*D): 115 * 69 * 23 mm / 4.53 * 2.72 * 0.91 in (without knob)

Trouble Shooting:
Q: Right channel has static. Tried different source and headphones. No help。
A: If there is static noise in one channel, normally it is caused by the tube of that channel. Maybe it has a poor contact after the long shipping process. You can open the chasis and adjust the screw near the tube while listening(contact us and we will give you a photo with marks to help you find it). Also, there is a small possibility that the tube is broken. You can buy a 5899 tube in local shops, which is very normal to see. And we will refund you the cost.
Q: It broke just now four loud pops and it's dead. Very disappointed.
A: Mainly because the battery is run out of power. Please charge it. If not help, please contact us.
Q: The Amp has a lot of electronic feedback/interference when a cellphone is hooked up to it or nearby. It creates popping in the headphones.
A: Vacuum tubes are easy to be interfered by devices that can trandfer siganl like cellphones, routers. Please keep the amp away from them.
Q: Won't hold a charge, sounds like something is loose inside.
A: The charger is broken. Please contact us to get a new one.

Packing List:
1 * headphone amplifier
1 * power supply
1 * 3.5mm audio cable
1 * band