Rega AOS MC – Phono Stage for MC Cartridges

British audio manufacturer Rega Research has introduced the new Rega AOS MC phono stage, specifically designed for moving coil cartridges (MC – Moving Coil). According to the developers, the new model is based on the flagship Aura.

The Rega AOS MC is positioned as a no-compromise, fully adjustable phono stage for MC cartridges, housed in a half-width chassis. The circuit design is largely derived from solutions developed for the Aura model – the company’s reference MC phono stage. The new unit is designed to work with a wide range of MC cartridges, providing sufficient gain for low-output models and extensive input loading options, making it a versatile partner for virtually any MC pickup.

 The Rega AOS MC is a fully analog two-stage amplifier with no digital control circuitry. The aluminum enclosure shields the internal circuit from radio frequency interference. The designers have eliminated unnecessary components and signal paths that could degrade audio performance. Among the innovative solutions is a self-regulating servo system that compensates for changes in ambient and operating temperatures.

The circuit employs parallel-connected low-noise FET (Field Effect Transistor) devices combined into a composite pair. The use of FETs ensures zero bias current through the cartridge coil, preventing disturbance of the cartridge’s delicate magnetic geometry. The unit allows selection of resistive loading from 70 to 400 ohms and capacitive loading from 1,000 to 4,300 pF. Input sensitivity can be adjusted in 6 dB steps. An automatic standby function is also included, activating when no signal is present; this can be disabled via switches on the rear panel.

The first stage is a symmetrical complementary Class A circuit using ultra-low-noise FET transistors from Linear Systems. This configuration eliminates bias current through the cartridge coil and removes the need for coupling components between the cartridge output and the input transistors, which positively affects sound quality. The transistors are carefully selected and matched in pairs for optimal performance. This stage controls the passive high-frequency section of the RIAA equalization. The second stage is a symmetrical differential Class A circuit with a common-base driver stage. It also serves as the active gain element in the low-frequency section of the RIAA equalization.

The manufacturer specifies a frequency response of 17.5 Hz (–3 dB) to 100 kHz (–0.2 dB), while RIAA accuracy is rated at ±0.2 dB from 65 Hz to 70 kHz with a 100 kΩ output load. Rega provides a lifetime warranty on its products, including the AOS MC phono stage. The Rega AOS MC MC phono stage is now available. In Europe, the recommended retail price is €1,999.