We are very pleased to announce that after a successful launch of the HA-1 Headphone Amplifier on May 7th, 2014, we have obtained additional stock of the HA-1 and they will be shipping immediately. You can purchase the HA-1 Headphone Amplifier direct on our website at OPPODigital.com
The analog audio section of the HA-1 is a fully balanced design with an emphasis on keeping the audio signal in the analog domain once it leaves the DAC. The HA-1 is anchored by a hefty toroidal power transformer, and linear power regulators and filters with custom made capacitors ensure that the headphone amplifier has a clean power source with plenty of reserve energy. The fully balanced Class A power amplification section uses hand-picked and paired discrete components to ensure symmetry, and a motor-driven precision volume control knob allows for both manual and remote control volume adjustment while keeping the audio in a pure analog audio path.
The beautiful "silver" edition of the HA-1 is still unavailable at this time, but it is scheduled to be released in June 2014. As you can see from the following image, it will be well worth the wait: