The New Headstage Arrow 4G is an innovative headphone amplifier that allows you to listen to high quality audio everywhere you go--in a sleek, ultra portable design. With an operation voltage of up to 12V and the best rail-to-rail operational amplifiers the Arrow is able to drive any headphones <600 ohms with authority. The sound is crisp and clean with defined highs and tight bass..

Fully Customizable Sound

While the Arrow does not color the audio signal, there are toggle switches to adjust gain, bass, treble and cross-feed. This allows the amp to be tailored to nearly any set of headphones, whether they are full size/high-ohm or low-impedance IEMs.

Automatic Power Adaptation

The "Arrow" is the only headphone amp to use an automatic power adaptation. The battery voltage of 4V is boosted to a voltage just as high as needed to provide a distortion-free sound--with a maximum voltage of 12V. This new technique provides the highest power output along with exceptional battery run-time. It is completely controlled by a microprocessor and free of any noise and pops.

No Power Degradation

Due to the power adaption there is no power degradation when the battery voltage falls. Even when the battery is nearly drained the amp will provide full power. A blinking red LED indicates that the battery needs to be charged rather than the standard distorted sound.

No Power Switch

The Arrow is the first amp that doesn't have an external power switch. A micro-controller detects audio signals and will automatically turn on the amp when music starts playing and off after the music stopped playing--with a 3 minute delay. 
  
Ultra Slim Design

The design with carefully selected parts provides an ultra slim design with a height of only 8.5mm (0.33''). It is one of the most portable amplifier designs in production today.

High Capacity iPod Battery

Despite the small size of the case it incorporates a lithium-ion battery that has more than double the capacity of rechargeable 9V batteries. It is the same battery that is used in the iPod 4th Generation so you will not have any problem finding a new one (if ever required). The smart design allows you to exchange the battery without soldering using the screw driver that comes with the iPod battery to open the case.

Arrow 12HE 4G Features

• Automatic Power Adaptation with up to 12V Internal Voltage
• Maximal 11V Output Voltage (Peak to Peak)
• 80 Hours Play Time in Lowest Power Mode (no voltage boost)
• 30 Hours Play Time in Highest Power Mode (12V)
• Three Selectable Gain Settings (2dB, 9dB, 18dB)
• Bass Boost (0dB, 3dB, 9dB)
• Treble Boost Switch New!
• Öhmann Crossfeed (Off, Low, High)
• Automatic Power Switch
• High-Capacity 1200mAh/4.2V Lithium-Ion Battery
• High Efficiency Battery Charging from USB Port
• Easy Battery Replacement without Soldering
• Symmetric & Short Audio Paths with Low Noise
• Analog Audio Input Jacks on Both Ends
• Two Headphone Jacks
• ALPS Analog Volume Potentiometer
• Low-Battery Indication (Slow and Fast LED Blinking)
• 4-Layer Circuit Board with two Ground Planes for Low Noise
• Black Anodized Aluminium Case with Laser Engraving
• Aluminium End Panels with White Silk Print
• Size: 8.5mm x 56mm x 98mm (0.33'' x 2.20'' x 3.86'')
• Weight: 75g 

Warranty

• 6 Month Indonesia Distributor

Package Contains

1 Arrow 12HE headphone amp (one battery installed)
1 USB cable 50cm (~20 inches)    

REview and awards

http://www.head-fi.org/t/475499/headstage-arrow-he-reviews-impressions-perceptions-sensations

http://www.head-fi.org/t/574116/delivery-of-headstage-arrow-he-4g