Rega Aos MC Phono Preamp

AOS MC is a high-performance moving coil phono stage designed to bring reference-level analogue performance to a wider range of vinyl systems. Drawing heavily on the circuit design of Rega’s flagship Aura MC, the AOS distills many of the same engineering principles into a more compact and accessible component. The result is a phono stage that delivers exceptional clarity, precision and realism from your vinyl collection. 

Designed and built around a pure analogue signal path, the AOS eliminates digital control circuitry and unnecessary components to preserve the integrity of the delicate signal produced by a moving coil cartridge. 

Aura-inspired analogue design

At the core of the AOS is a two-stage Class A amplifier topology derived from Rega’s reference Aura MC phono stage. The circuit uses ultra-low-noise parallel FET transistors configured as compound pairs to maximize detail retrieval while maintaining an exceptionally low noise floor.

A key advantage of this design is that the FET configuration ensures no bias current flows through the cartridge coil, preserving the cartridge’s delicate magnetic geometry and allowing it to operate exactly as intended.

Rega also minimizes coupling components between the cartridge and amplification stage, reducing potential sources of signal degradation and ensuring the purest possible path from stylus to system.

Flexible cartridge compatibility

The AOS is designed to work with a wide range of moving coil cartridges - from Rega’s own models to third-party designs. Rear-panel switches allow users to fine-tune the phono stage for optimal performance with their cartridge.

Adjustments include selectable resistive loading from 70Ω to 400Ω, capacitive loading from 1000pF to 4300pF, and a switchable 6 dB gain adjustment to accommodate very low-output cartridges.

For convenience, the unit ships factory-preset for Rega MC cartridges, allowing immediate plug-and-play performance while still offering full adjustability when needed.

Built for pure analogue performance

The AOS follows Rega’s philosophy of keeping the signal path simple and interference-free. Its rigid half-width aluminium chassis provides excellent shielding from electromagnetic interference while maintaining a compact footprint that integrates easily into modern hi-fi systems.

Additional design features such as a self-adjusting servo circuit help maintain stable performance despite changes in temperature, while an automatic standby function reduces power consumption when the unit is idle.

Positioned between the Fono MC Mk4 and the flagship Aura MC, the AOS offers a compelling balance of reference grade engineering, flexibility and musical performance for serious vinyl listeners. 

Key Features

• Dedicated moving-coil phono stage

• Circuit design derived from the Rega Aura MC reference phono stage

• Two-stage fully analogue Class A amplifier design

• Ultra-low-noise FET compound pair input stage

• Adjustable resistive loading: 70Ω / 100Ω / 150Ω / 400Ω

• Adjustable capacitive loading: 1000pF / 4300pF

• Switchable gain (63.5 dB / 69.3 dB)

• Self-adjusting servo control for temperature stability

• Automatic standby function

• Compact half-width aluminium chassis with RFI shielding

• Factory preset for Rega MC cartridges