Audiobyte is the best digital audio company you’ve never heard of. In fact, Audiobyte is a subsidiary of Romanian digital experts Rockna Electronics and if you follow the digital audio world closely, you’ll definitely know that name as both the brand in its own right and the products produced by its clever design team.
Audiobyte’s current Hydra line comprises Hydra.VOX DAC with headphone amplifier and its supplied Hydra.ZAP power supply. The keen-eyed might spot two sets of power feed outputs from the Hydra.ZAP; a matching Hydra.HUB digital transport was in final development at the time of the review and is expected to cost less than £2,000. There is also a control app already available on Google play, but us i-Users will have to wait.
Both units sit side-by-side or on top of one another with a near-identical three-quarter sized case with an informative colour touch screen in the centre. These allow you to drill down deep into the options of both devices, enabling you to do anything from fine-tuning the voltage. It uses a supercapacitor array to feed the ±5V for the digital side of the system while the 8V reference voltage and the main analogue stage (which can be set anywhere from ±16.5V to ±19.5V, is optimised at 18V and I liked it best at 19.1V) are well regulated. The array does take some considerable time to charge, but both the display and a drop in noise from the power supply (moving from ‘near-silent’ to ‘silent’) tell you when the array is fully charged. A little green light tells you whether ‘Vox’ or ‘Hub’ are connected, and you should only connect or disconnect the devices from the Hydra.ZAP when it is in standby. One point not made clear in the manual is the connection is not completed until the supercapacitor is fully charged, and that means the first hour or so waiting for the caps to saturate could result in frantic ‘it’s not working!’ calls to the manufacturer or distributor, especially as the first reaction here would be to put the DAC into standby, which stops the capacitor charging process. The DAC takes some time to run-in, too; the sound you get immediately after that first hour and the sound you get a few dozen hours later is quite different; the scale and refinement are there from the outset, but the harmonic structure to the sound and the way it puts music together in an extremely organic manner takes some time to appear.
The Hydra.VOX is fed by the Hydra.ZAP using two umbilical cables; one five-way cable feeding the digital audio circuitry and an eight-way cord for the analogue power supplies and the reference voltages. When connected, there’s a dim Audiobyte logo on the front panel in standby, but on powering up, the panel is just as informative as the power supply, and you might want to deep dive into the menu to set up PCM and DSD in the best possible settings for your tastes and system. You can adjust filter settings for both types of file (or run DSD in direct mode), you can defeat the headphone socket and run the DAC at full level and enable/disable the autodetect for the headphone socket. If you use the level control, there are up and down controls in pale blue at the bottom of the touch-screen. While discussing the screens, remember when powering the DAC up or down, you do so from the power supply, not the DAC (like an idiot, I spent several minutes mashing the front panel of the DAC looking for the standby button).