Aesthetically the HA-2SE continues the HA-2's elegant style and design - genuine leather casing with contrast stitching and bevelled aluminium edges. Inside, the digital-to-analog converter (DAC) chip is upgraded to ES9028Q2M, top-of- the line from ESS Technology's SABRE 32 Reference series for portable designs. The headphone amplifier is further optimised for very sensitive In-Ear Monitors, with lower noise floor and higher signal-to- noise ratio over the HA-2.
OPPO HA-2SE is engineered to enhance music playback from mobile phones and portable music players. Featuring hybrid class AB amplification and a USB DAC, the HA-2SE offers high-performance digital-to- analogue conversion for Apple's iPhone/iPod products, a wide range of Android devices, PC and Mac computers. Equipped with a 3000mAh internal battery and OPPO's patented safe rapid charging technology, The HA-2SE may be conveniently used to charge mobile devices on-the- go and itself can be efficiently charged in 30 minutes.
Hybrid Class AB Amplifier
The HA-2SE's power amplification circuit for the headphones is Class AB built with integrated circuits (ICs) and discrete transistors. The discrete transistor output stage uses hand-picked and matched parts. The output transistors are biased to operate in their most linear range for the critical small signal and deliver their full potential when power is required.
Clean Signal Path
There is no DSP (Digital Signal Processor) in the HA-2SE. Volume control is operated by a combination of the DAC chip's internal digital volume control and an analogue potentiometer (the familiar volume knob). Bass boost is performed by pure analogue audio circuits. By avoiding re-digitizing the audio signal for volume adjustment or bass boost, the HA-2SE provides a clean signal path for the audio.
Audio-In and Line-Out
The HA-2SE has a 3.5 mm Audio-In port to support portable music players that do not have a USB-compatible digital output. While the HA-2SE is used with one of its USB digital input ports, the 3.5 mm jack acts as Line-Out for the USB DAC.
ESS Sabre32 Reference DAC
The DAC is one of the most important components for digital audio playback. The ES9028-Q2M DAC chip used in the HA-2SE is the latest flagship mobile DAC developed by ESS Technology. With the ESS patented 32-bit Hyperstream DAC architecture and Time Domain Jitter Eliminator, the SABRE32 Reference DAC delivers an unprecedented performance for mobile applications.
Asynchronous USB DAC
By bypassing the smartphone's built-in DAC and headphone amplification circuit that is often cost-constrained, the HA-2SE turns a smartphone into a high performance digital audio player. The asynchronous USB DAC input of the HA-2SE also works with PC and Mac computers to replace the built-in sound card and support high-resolution audio playback with PCM up to 384 kHz 32-bit and DSD up to 12 MHz (DSD256).
For those who like a bit more punch and impact with their music, the HA-2SE offers a Bass Boost function. With Bass Boost off, the HA-2SE delivers a ruler-flat frequency response; with Bass Boost on, the HA-2SE adds force and impact to the sub-bass region without muddling the important mid- to high-frequency bands.