The OPPO HA1 is their flagship class A headphone DAC/amplifier combo, it’s their first attempt into the high end headphones market and it is intended to be a reference DAC/AMP

OPPO designs the HA-1 headphone amplifier with the same versatile approach as they do with their Blu-ray players. The HA-1 is a high performance headphone amplifier, plus an asynchronous USB DAC, a stereo pre-amplifier, a digital audio dock for mobile devices, and a Bluetooth audio transport. Users have a choice of using the 4-pin balanced XLR or the traditional quarter-inch headphone jack. Line level analog inputs and outputs are provided with both RCA and balanced XLR sockets.

The USB DAC supports PCM audio up to 384 kHz 32-bit resolution and DSD audio up to 256x. The same ESS 9018 Sabre32 Reference DAC and output driving stage used in OPPO audiophile Blu-ray players ensure extremely low noise and low distortion performance.  

• Compatible with Apple’s iPod, iPhone and iPad for use as an external DAC
• Class A Headphone Amp and Pre-Amp
• Bluetooth with Apt-X codec for high quality wireless audio
• Display Driven Interface
• Fully Balanced Design
• Adjustable Gain Setting to suit al types of headphones 
• Remote Control & App
• Stereo Pre-Amplifier with Home Theater Bypass