Audiobyte Hydra Vox DAC

Hydra VOX is a unique D/A converter with a headphone amplifier and external power supply (ZAP). Its entire architecture is built from the scratch around a Xilinx 7-series FPGA device. All main functions of the device are specifically made inside the Xilinx device which is updatable, meaning new software will refresh the DAC on the hardware level. Attaining a high performance 1-bit converter requires extensive digital processing. In order to keep a pristine sound quality, the processing must be done in a resolution higher than the music itself. Using 80 DSP cores running at 200 MHz and 68-bit processing, VOX has enough computing power to preserve the transparency required by the most demanding audiophile. A unique feature of the Hydra.VOX is the seamless integration between analog and digital filters in orders to preserve accurate phase of the audio signal. It is well-known that any analog low-pass filter will add a phase distortion input-to-output altering sound quality. To avoid this from happening, the digital filters inside FPGA are programmed to exhibit a “mirrored” phase response, thus cancelling the phase error from the analog domain. The result is a perfect phase response over the audio band. The quality of the conversion clock is crucial in a high-speed 1-bit system. The VOX uses a high-quality DPLL clock generator which is integrated into a jitter reduction architecture. By design, it does not require any Asynchronous Sample Rate Conversion solutions to achieve this. While trivial in general applications, the analog buffer stage of the 1-bit DAC is a critical component. Not only must it eliminate the residual noise, but also it should have extreme performance in terms of low distortion and noise floor. In the VOX, the analog buffer stage is realized using low noise bipolar discrete devices. Another feature of the VOX DAC is the possibility to directly convert DSD256/512 signals, bypassing all internal processing. This is possible only on USB and I2S inputs. Please note that volume control will not be available if this setting is active and headphone output will be muted. The VOX has a 35-bit data path and a very high quality 32-bit volume control, therefore can drive directly any power amplifier. The built-in headphone amplifier is entirely a bipolar discrete design with a max power of 3W/16 ohms.
HYDRA ZAP – External Power Supply for HYDRA VOX 
The ZAP is the VOX-partner dedicated low noise power supply. It can be fully controlled via touchscreen display or with our custom remote-control app for Android abd iOS. It provides clean power supply for the VOX line-up: symmetrical analog, digital and reference voltages. The Digital supply is a low noise, low impedance, ultra-capacitor-based power supply. It features a large capacitor bank of 2 x 310 Farads. The charging process is a seamless, microprocessor-controlled process with progress tracking graphics on the ZAP display. The ZAP provides a very clean reference power supply needed for the VOX. It is made using discrete regulation and can be manually changed in case the ZAP is used independently. For the headphone amplifier, the ZAP has a section of complementary adjustable discrete regulators. These are shunt mode high rejection stages based on proprietary Audiobyte technology. The Hydra.ZAP has extensive monitoring and control capabilities. All voltage values (except reference voltages) and current consumptions are shown in real time on the product display. The complementary analog voltages powering the headphone amplifier can be manually adjusted in fine steps or by directly input of the voltage.