From the 6Moons Review,
"Compared to Metrum Hex direct as the type of comparison potential buyers would find most relevant, the Hydra X+ improved what I thought of as timing. This manifested most notably on transients as the initial rise of sounds from silence being better defined. During complex passages this led to greater definition. It directly assisted better separation as the ability to follow many overlaid intertwined lines without suffering shadowing effects of partial obscuration. Lastly, minor tendencies for image bloat disappeared."
"Sonically my $1'350 two-box SOtM ride with super-clock feature had no definitive advantage. If there were any differences (depending on track I felt quite uncertain), they operated solely in the domains of relative soundstage depth and subjective speed. Sometimes the Hydra X+ seemed to have me more aware of a bit of added stage depth."
-Srajan Ebaen, 6Moons.
What is the difference between the X+ and the Z? Glad you asked. It's as follows:
what it has like the X:
- same formats capability
- same quality clocks
- same isolation
what it has more over the X :
- more outputs (6 in total : wordclock, bnc, spdif, aes, i2s, optical)
- all connectors on the back panel
- better chassis with 10 mm front panel
- less clock interference (on X both clocks are running simultaneous , in Z just the clock needed for the corresponding sample rate) = less jitter
- the output polarity of the clocks on I2S out can be altered via jumpers (for extended compatibility with other dacs)
- the DoP feature can be switched on or off (DoP = off, continuous stream between tracks, DoP = on, stream is reset between tracks)
- can run directly powered from usb or externally powered
- firmware is upgradable over usb
Getting the best from computer audio seemed so simple at first. Well, if time has taught us anything, it's that not all computer audio is created equal. The differences between a direct usb connection, and one that has been properly isolated and converted is a big difference. In the case of the Hydra-X the USB signal is converted to AES/EBU, I2S, SPID/F, or Optical. Essentially it gives us the best usb connect to a dac that we've yet experienced. To do this, it uses super fast FPGAs and a battery power supply.
Getting the best from computer audio begins here, but don't take our word for it, here are some stellar reviews:
"I did not expect this, nor did I want this, as this isn’t a very cheap component to add to your system.
However, I must say that the difference was incredible! Mark my words, the sound was entirely brought to another level. It was like I bought a much better dac/amp."- HeadMania.org
"Firstly in years I could hear the results instantly and with the large pace through digital front end. Everything was present as raw and directly at my face.
I’m still hard-core analogue fan, but things are finally getting into the right direction with digital. I’m always listen about how much precision, knowledge and tuning is needed on the analog side. Well, It “ain’t” any different on the shores of digital Audio Ocean. Hydra X from Audiobyte is a big and better step into make things easier to integrate with DAC’s." -Matej Isak, Mono and Stereo
"After long listening sessions (with the unit I used in May) I sincerely congratulate Nicolae, who has created an excellent product. Although the final form obtained from the computer will be used to decide DAC, but Hydra-X will give him a signal of high quality, clean, detailed, with impressive black background, with a large spread dynamics, with strong, well-defined basis for bass, smooth and saturated diameter and open, retail, full air mountain ranges." Marek Dyba, High Fidelity PL
Here's more from the Audiobyte website :
Either if you love your current setup and don't want to change your DAC, or just want to upgrade your current usb interface, the Hydra-X is the perfect way to add (or improve) computer based playback on your system.
The Hydra-X(treme) was designed as the ultimate USB interface in terms of both objective and subjective performance. Built around the latest generation of FPGA technology, the goal of the design was to produce stunning sound and to offer the highest definition available for a commercial product.
To achieve this goals some key factors are defining the Hydra design :
The ultra high-speed usb interface,
capable of very high audio sample rates. The Hydra is equipped with a modern ARM processor for resolving usb transactions.
between noisy PC environment and the audio chain. The USB isolation for audio devices is nothing but tricky. If you choose to use usb isolators, then sample rate will become limited, which is not an option. If you choose to isolate the output, you are adding significant amounts of jitter to the signal. By using a clever circuit topology, the Hydra design avoids these two bottlenecks. The isolation is placed between the ARM processor and the FPGA audio core, therefore not limiting the bandwidth. Being before the clocks, it's jitter contribution becomes irrelevant. See the Hydra-X technical paper for more details.
The Spartan6 FPGA
is the heart of the Hydra. This advanced programmable circuit is offering a bit-transparent processing and signal conditioning to S/PDIF, AES/EBU, Toslink and I2S outputs. It also gives the ability of the Hydra to output raw dsd audio streams.
unlike other products which only specify "low jitter clocks", we are saying the exact type of what we're using: it's the CCHD-950/957 type from Crystek, one of 45.1584 Mhz and one of 49.152 Mhz. You can check real graphs of these ultra-low phase noise clocks here. The clocks are system masters. In order to remove any jitter induced by the FPGA circuit itself, special retiming is applied just before the Hydra outputs.
a low impedance, LiPo-nano technology, provide to the system the cleanest power supply needed for pristine audio performance. All sensitive circuitry like the clocks, FPGA and retiming circuitry benefit from battery power. The USB port and external (optional) are alternative options for powering the system, but everything was primarily designed to work with clean battery power.
Careful pcb layout
is often neglected in the rush of getting a product quickly into the market. The Hydra-X design time took many months until everything came close to perfection, until the shortest routing paths, the best decoupling places, the less interference and crosstalk placement for the components are found.
USB receptacle, type B high-speed
1) S/PDIF, 75 ohm coaxial
2) AES/EBU, 110 ohm XLR
4) I2S over HDMI (LVDS)
Supported sample rates, pcm:
1) 44.1 KHz
2) 48 KHz
3) 88.2 KHz
4) 96 KHz
5) 176.4 KHz
6) 192 KHz
7) 352.8 KHz
8) 384 KHz
Supported rates, dsd:
1) 2.8 MHz (DSD64) - DoP, native
2) 5.6 MHz (DSD128) - DoP, native
3) 11.2 MHz (DSD256) - native (via ASIO)
4) 22.5 MHz (DSD512) - native (via ASIO)
1) 32 bit over I2S output
2) 24 bit over S/PDIF, AES/EBU, Toslink
1) Native MacOS 10.6 and later
2) Native Linux with UAC2 compliant kernel
3) ASIO, WASAPI, KS, DS drivers for Win XP to W8 32/64 bit
4) Recommended players : Foobar2000, Audirvana Plus, Jriver18 etc.
1) Power consumption : 0.7 W
2) Battery charge time : about 90 min.
3) Battery playback : about 540 min.
4) Dimensions : 125 x 105 x 60 mm
5) Weight : aprox. 0.8 kg