XM4 Portable Headphone Amplifier

This amp has an interesting digital/microprocessor control of power-on time with auto off by pressing the power button different number of times.

Specification

* Anodized extruded aluminum case
* Laser-anodized glossy aluminum faceplate
* Bass Boost of +6dB @ 100Hz when enabled
* Variable crossfeed, user-adjustable, with bypass
* Auto Power-off, saves battery life
* Built-in battery charger
* Maximum gain is jumper-settable by user
* Integrated voltmeter displays battery voltage
* Low battery indicator
* Blue LED and amber LED indicate status.
* FlashLight mode
* Microprocessor controlled
* Gold-plated amp chip socket, allows for amp upgrades
* Power jack or USB port (depending on model) allows external power supply or computer to power the unit and/or recharge the battery.
* Ergonomic compact design for portability.
* Uses 0.1% tolerance mil-spec resistors in the analog feedback circuit.
* Uses TLE2426 rail splitter, with noise reduction, to create a stable and low-noise analog ground.
* Uses OPA2134 ultra-low distortion (.00008%) low-noise high performance audio amplifier.
* Audio power supply bypassing uses both high-value Electrolytic and Tantalum capacitors to create an ultra-stable low-noise low-impedance power supply.
* Polished Aluminum volume knob.
* Proper dual-layer impedance-controlled Printed Circuit Board.
* Optional Lithium-Ion FastCharge® System is available.