Discrete Class A Amplifier - A Class A amplifier conducts signal over the entire range of the input signal cycle. The output transistors are biased to operate in their most linear range, and there is no crossover distortion caused by switching the signal between two push-pull devices. The HA-1's power amplification circuit for the headphones is Class A built with discrete transistors. The discrete design allows us to hand-pick and match the best parts to build the HA-1.
Fully Balanced Design – The internal analog audio signal path of the HA-1 is fully balanced. For digital audio, the signal runs in balanced mode all the way from the DAC to the output jacks. Balanced analog input is kept intact, and single-ended input is converted to balanced at the input buffer. All single-ended outputs are derived from the balanced signal as well. The balanced design provides better common-mode noise rejection and improves signal quality. The balanced headphone output provides twice the voltage and four times the power of the single-ended output, enabling the HA-1 to drive the most power hungry headphones. It also provides better channel separation by eliminating the common ground return path.
Clean Signal Path – The HA-1 uses an analog potentiometer (the familiar volume knob) to control the volume. By avoiding re-digitizing the audio signal for volume adjustment, the HA-1 provides a clean signal path for the audio. At the same time, the convenience of modern digital volume control is not lost - a remote-controlled motor turns the volume knob and a 10-bit analog-to-digital converter samples the signal to display a numeric dB level.
Toroidal Power Supply – A toroidal power transformer offers superior power efficiency and much lower exterior magnetic fields over traditional laminated steel core transformers. The HA-1's toroidal linear power supply provides a very clean and robust power source to the audio components.
ESS Sabre32 Reference DAC – The DAC is one of the most important components for digital audio playback. The SABRE32 Reference ES9018 from ESS Technology is the world’s best performing 32-bit audio DAC solution targeted for high-end consumer applications and professional studio equipment. With the ESS patented 32-bit Hyperstream™ DAC architecture and Time Domain Jitter Eliminator, the SABRE32 Reference DAC delivers an unprecedented DNR (Dynamic Range) of up to 135dB and THD+N (Total Harmonic Distortion plus Noise) of -120dB, the industry’s highest performance level that will satisfy even the most demanding audio enthusiast. To learn more about the technologies behind the exceptional performance of the SABRE DAC, please read the SABRE Technical White Paper.
Asynchronous USB DAC - By bypassing the low fidelity, poor quality DAC of traditional computer soundcards, the HA-1 turns any computer into a high performance multi-media source by converting digital audio to analog through the ESS Sabre32 Reference DAC. The asynchronous transfer mode uses the high precision clock inside the HA-1 to drive the audio signal, not relying on the clock quality of the computer. HA-1's USB DAC input supports PCM up to 384 kHz 24-bit and DSD up to 12 MHz (DSD256).
Made for iPod®, iPhone® and iPad® – The HA-1 passes Apple's "MFi" certification and is compatible with the latest iPod, iPhone and iPad to be used as the digital audio output accessory of these devices. By tapping directly into the digital audio signal of these devices and converting the audio to analog using the high performance SABRE32 Reference DAC, music from your favorite portable device will sound its best.
Wireless Audio via Bluetooth - The HA-1 supports Bluetooth Advanced Audio Distribution Profile (A2DP) with both the standard and aptX® high quality codec. Simply pair your phone with the HA-1 and set music free wirelessly from your mobile phone.
Stereo Pre-Amplifier with Home Theater Bypass - The HA-1 doubles as a high fidelity stereo pre-amplifier with both RCA and XLR output ports. A special "Home Theater Bypass" mode can be assigned to any input source, making it very easy to integrate the HA-1 as a stereo pre-amplifier into a home theater sound system.
Trigger Input & Output – The HA-1 features 12V trigger input and output. When used as a stereo pre-amplifier, the trigger output can turn on your power amplifiers automatically when the HA-1 is turned on. You can also turn on the HA-1 automatically by connecting its trigger input to the trigger output of a source device or a surround sound processor.
Remote Control & App – The HA-1 comes with a remote control that provides volume control, direct source selection and even playback control for digital audio sources. A remote control app is available for both Apple's iPhone and Android-based smartphones. The app works over Bluetooth and offers the same functionality as the physical remote control.
Adjustable Gain Setting – The headphone power amplifier has an adjustable gain setting. For optimal sound quality and to best match your headphones' sensitivity, you can choose between Normal and High for the Headphone Gain setting.
Build Quality – The HA-1 is housed in a brushed aluminum chassis. The Class A amplifier naturally consumes more power and generate more heat than other types of amplifiers, so the HA-1 is designed with ample ventilation and built with the finest components to ensure long term stability and performance. Tipping the scale at 13 lbs, the HA-1 is a solidly built desktop headphone amplifier.