Aurender MC20 Flagship Master Clock

Aurender MC20 Flagship Master Clock

The Aurender MC20 is a reference-grade master clock and word clock generator designed to provide a precise and stable timing reference for compatible music servers, digital transports, DACs and digital audio processors. By synchronising multiple components in the digital signal path to the same clock source, it helps minimise timing errors and creates the foundation for coherent high-resolution digital playback.

The MC20 combines a rubidium-based 10MHz master clock with two independent OCXO word clock generators. This dual architecture allows it to support components equipped with a fixed-frequency 10MHz master clock input as well as DACs and processors that require sample-rate-related word clock signals.

Rubidium 10MHz Master Clock

At the heart of the MC20 is a rubidium clock module that generates an exceptionally stable 10MHz reference signal. Rubidium technology is used for its high short- and long-term frequency stability, low phase noise and ability to provide a consistent timing reference for demanding digital audio systems.

Four independent 10MHz master clock outputs are provided. Two use a 75-ohm impedance for connection to compatible Aurender music servers and other 75-ohm equipment, while two additional 50-ohm outputs support compatible DACs, master clocks and digital processors from other manufacturers.

Dual Discrete OCXO Word Clock Generators

For equipment that does not accept a 10MHz master clock signal, the MC20 incorporates two separate oven-controlled crystal oscillator word clock generators. The two channels can be assigned to the 44.1kHz and 48kHz sample-rate families and operate independently from the rubidium master clock outputs.

Each word clock channel provides two 75-ohm BNC outputs, allowing the MC20 to supply four word clock connections simultaneously. This makes it possible to synchronise a source component, DAC and additional digital processing equipment within the same system.

Automatic SPDIF Synchronisation

A dedicated 75-ohm BNC SPDIF Sync input allows the MC20 to identify the sample rate of the signal being played by a connected digital source. In Sync Mode, the appropriate word clock base frequency and multiplier are selected automatically as the source material changes.

This automatic operation is especially useful for music libraries containing recordings with different sample rates, eliminating the need to adjust the word clock frequency manually from one album or track to another.

Manual Word Clock Selection

The word clock channels can also be configured manually using the front-panel controls. The user can select a 44.1kHz or 48kHz base frequency together with the appropriate multiplier for PCM and DSD material.

Clearly arranged LED indicators show the selected base frequency, clock multiplier, synchronisation status and rubidium-module lock condition. Both word clock channels remain independently configurable, allowing the MC20 to accommodate digital components with different clocking requirements.

Flexible System Integration

The MC20 can simultaneously supply a 10MHz master clock signal to an Aurender music server and a compatible DAC. When a DAC accepts only conventional word clock, the Aurender source can receive the more stable 10MHz reference while the DAC receives a sample-rate-matched signal from one of the OCXO word clock channels.

The availability of both 75-ohm and 50-ohm master clock outputs provides broad compatibility with high-end digital audio equipment. Correct impedance matching between the clock output, cable and receiving component is essential for maintaining signal integrity.

Independent Master Clock and Word Clock Operation

The four rubidium 10MHz outputs and four OCXO word clock outputs operate independently and can be used at the same time. This enables the MC20 to serve as the central timing reference in complex digital systems rather than being limited to synchronising a single source and DAC.

For compatible Aurender components equipped with a clock input, Aurender recommends using the 75-ohm 10MHz master clock connection. The word clock outputs remain available for DACs and other equipment that require sample-rate-specific clock signals.

Rubidium Warm-Up and Lock Monitoring

After the MC20 is switched on, the rubidium module requires a short warm-up period to reach its optimal operating temperature. The front-panel Lock indicator flashes during this process and remains steadily illuminated when the clock has stabilised.

Aurender recommends leaving the MC20 powered on during regular use so that the rubidium module remains at its ideal operating temperature and is ready to provide a stable reference signal.

Reference-Grade Construction

The MC20 is built in a substantial full-width chassis weighing 20.3kg. The sensitive rubidium module is housed in a removable assembly and supplied in protective packaging to reduce the risk of shock during transportation.

With four 10MHz master clock outputs, four independently configurable word clock outputs and automatic SPDIF synchronisation, the Aurender MC20 provides a comprehensive external clocking solution for advanced digital audio systems.