FiiO A3 Portable Headphone Amplifier (Black)

Specifications:

• Suitable for headphones ranging from 16 to 150 Ohms. Gain switch for matching output to headphone power needs.
• FiiO A3
• Fully discrete bass boost circuit increases output by 3.5dB at 60Hz, with bypass when off.Please add trouble shooting steps. Regarding charging and operation of the E11K The E11K utilizes the typical Micro USB port for charging and can operate even while charging. The blue LED will pulsate while charging and light steadily when fully charged. Charging takes roughly 4 hours and may be carried out by any USB power adapter of 5V and ≥500mA current capacity. The E11K may operate continuously for about 16 hours on a full charge. If the E11K won't turn on, please try charging it first; if it still doesn't work, please contact FiiO for service!
• Superior sound quality through expertly selected components and design, utilizing OPA1642 preamp and AD8397 amp section.Problems with the sound output of the E11K. If the sound output of the E11K crackles or cuts out on one or both channels, the cabling on the line in interconnect and / or the headphones may be broken or the contacts oxidized. Please try changing to another interconnect and / or pair of headphone. If the jacks on the cabling have oxidized you may try cleaning them using contact cleaner or rubbing off the oxidation with a piece of tissue. If none of the above works, please contact FiiO for service by sending email to support@fiio.net!
• Handsome all aluminum body and chassis is sturdy and shielding against EM interference.Why is the sound from the E11K/E12/E12A skewed to one side at low volume? This is the behaviour of all analog potentiometers (volume controls). Please switch to low gain for sensitive earphones. All is normal if the channel balance is audibly normal at normal listening volumes. If channel balance at very low volumes is vital for you, please consider choosing our E17/E17K series headphone DAC/amps with digital volume control.