Auralic Leo GX

LEO GX is a breakthrough in digital audio system clocking — the first master clock ever that can feed a DAC directly with a working signal so precise we had to use new benchmarks to measure its performance. Wider staging, pinpoint locational accuracy, and an expanded dynamic range are just some of the benefits you’ll hear when you implement LEO GX’s one-of-a-kind approach to clocking that literally bypasses the traditional limitations of internal DAC clocks.

A Breakthrough in Digital System Clocking
As digital music formats and system components march ever forward in quality and capabilities, high-end audio systems increasingly rely on the precision of their clocks to keep the digital realm in order. The greater dynamic range of high resolution files for example is only realized with the help of modern clocks that are capable of working frequencies nearly ten times higher than what was common just a handful of years ago. However, today’s high-frequency DAC clocks are costlier and much harder to design and build than ever before.

Traditional Clocking
Normally, phase-locked loop circuits (PLL) in a DAC are used to synchronize its internal working signal with the more accurate incoming signal from a reference clock. But they’re noisy. And even though the working signal can be nudged a bit to match up with the reference signal, its frequency — and the precision of the analog waveform that’s based on it — is ultimately limited by the DAC’s own clock circuit.

Direct-to-DAC Design
Thanks to its unique Jitter-Free Operation, when the VEGA G2 joins forces with the LEO GX these devices accomplish something extraordinary. Instead of merely synchronizing with the LEO GX, the VEGA G2 actually uses the exceptionally high frequency incoming clock from the LEO GX directly — as its own working signal. In other words the LEO GX bypasses the internal VEGA G2 clock circuit entirely, and drives waveform creation directly with its signal. No more PLL, and no more limitations.

A New Description of Performance
The LEO GX clock is so precise that existing benchmarks aren’t detailed enough to accurately represent what it can do. Instead, we use Allan deviation to describe the resolution of the LEO GX, which is like looking at phase noise closely enough to detect shifts of +/-1Hz or even +/-0.1Hz. The Allan deviation of the LEO GX Reference Master Clock comes in at 2E-12 (at 1 second), which is equal to a 10MHz rubidium atomic clock with phase noise of +/-1Hz at -110dBc/Hz, or an amazing 500 times less jitter than an 82fs Femto clock oscillator.

Clock Structure
LEO GX hardware starts with two temperature-controlled rubidium atomic reference clocks. Each is paired with an oscillator using stress compensated cut crystals, for thermal and mechanical resilience and low phase noise performance. The result is the LEO GX’s remarkably high signal frequencies: 90.316MHz for 44.1-based audio signals, and 98.304MHz for 48K-based signals.

Optical Isolation
We’ve gone to great lengths to reduce interference and noise in the new LEO GX, including the use of optical isolation techniques that keep systems physically separated from each other. Control signals from the processing circuit are sent to the clock circuit via fiber optic cables instead of electrical pathways, so the source of LEO GX’s impeccable timing is never disturbed.

Unity Chassis
Designed specifically for the premium lineup of AURALiC G Series devices, the Unity Chassis is machined from a single billet of aluminum that provides the LEO GX with superior shielding from EMI noise. It’s the perfect working environment to create the ultra-precise, high frequency feed that can take the performance of your G system to new heights.

Perfectly Balanced
LEO GX internal circuits are physically distributed to enhance overall balance and performance. And its specially designed foot spikes dampen and absorb vibrations so the operation of its internal clock always starts with a rock-steady foundation.

Dual Purer-Power Linear Power Supplies
We’ve given the LEO GX two of our ultra-quiet Purer-Power linear power supplies, galvanically isolating them from each other in the obsessive quest to reduce noise and create a pristine working environment. One Purer-Power supply feeds the LEO GX’s processing system, while the second powers the clock circuit. Interference between the areas is reduced to minimum, so there’s nothing to get in the way of LEO GX’s stellar performance.

Realize Full Potential
The LEO GX is such a precise clock, running at very high frequency, you will need the best interconnect cable to realize its full potential. We created a cable specifically for LEO GX, made from 60GHz bandwidth military aerospace-grade material and connectors. Handmade and precisely tuned, it comes with a performance data report so you can be sure its specs are well capable of the task at hand.

Specifications

Benchmark
Allan Deviation: 2E-12 (1 second)
Equivalent Jitter: 500 times less than an 82fs femto clock (1Hz-10Hz)
Equivalent Phase Noise: -110dBc/Hz@1Hz (Ref Frequency: 10MHz)

The Clock
Frequency: 90.3168MHz (44.1KHz) | 98.3040MHz (48KHz)
Output Level: 3.3V CMOS (Direct-to-DAC Design)
Reference: Temperature-controlled Rubidium atomic clock
Oscillator: Temperature-controlled SC cut crystal

Sampling Rate
PCM: 44.1KHz to 384KHz in 32Bit
DSD: DSD64 to DSD512 in 44x and 48x

System Control
Switch sampling rate automatically via Lightning-Link with G2 DAC

Power Supply
Dual Purer-Power internal linear power supply
10uV low noise designed for audio circuits

Noise Elimination
Optical isolation between control and clock circuits
EMI-shielding Unity Chassis

Network
Gigabit Ethernet (For firmware upgrade use)

Power Consumption
Warmup: 30W at max
Running: 15W

Dimensions – W x D x H
13.4 x 12.6 x 3.2 in. (34cm x 32cm x 8cm)

Weight
17.8 lbs (8.1kg)

Product Finishing
Anodized precision-machined aluminum case in matte black

Contents
AURALiC LEO GX Reference Master Clock
Hex wrench (for use of tighten clock cable)
Users’s guide
Power cord
Lightning-Link cable
Basic version: High quality RF clock cable
Premium version: 60GHz aerospace grade clock cables