Rega Aos MC

Between the Fono MC MK4 and the flagship Aura MC, there was a missing link. The Rega Aos MC fills that spot with a design that takes the Aura’s fundamental principles and brings them into a half-width format. Presented at the Bristol Hi-Fi Show 2026 ahead of its March launch, this 100% analog preamplifier targets moving-coil cartridges with high gain and extensive adjustment options. Made in the UK, it comes with the Rega lifetime warranty.

Class A amplification without bias current

The Aos MC operates in two stages, both in Class A. The first stage uses ultra-low-noise FET transistors from the American manufacturer Linear Systems, connected in parallel and configured as symmetrical complementary pairs. This topology eliminates bias current which, if it passed through the cartridge coil, could alter its magnetic geometry. The signal goes directly into the FETs without passing through coupling capacitors, which shortens the path and reduces potential sources of degradation.

The second stage, a symmetrical differential amplifier with a common-base driver, provides active amplification of the low-frequency part of the RIAA correction. Equalization combines passive networks (for high frequencies) and active ones (for low frequencies), with stated accuracy of ±0.2 dB between 65 Hz and 70 kHz. A self-adjusting servo compensates for thermal drift, whether from the environment or from the unit’s internal heating.

Four impedance values, two gain levels

Settings are adjusted via DIP switches located on the back of the unit. Input impedance can be set to 70, 100, 150, or 400 Ω, capacitance to 1000 or 4300 pF. An additional switch lowers gain by 6 dB (from 69.3 to 63.5 dB), which broadens compatibility with MC cartridges that have a higher output level. Factory settings correspond to Rega cartridges (Ania, Ania Pro, Apheta 3, Aphelion 2), but the Aos adapts just as well to models from other manufacturers.

This flexibility is, however, limited to MC cartridges. No MM input is provided: Rega reserves this function for the Fono MM MK5 and is preparing an Aos MM model for those who want an equivalent in the new range.

A compact chassis, a streamlined circuit

The half-width aluminum chassis (22 × 8 × 33 cm, 2.9 kg) follows the aesthetic cues of the current range: understated black finish, front panel with push button and backlit logo. Aluminum also plays a technical role by shielding the circuit against radio-frequency interference (RFI). Inside, Rega has deliberately limited the number of components to favor a direct signal path. A shielded toroidal transformer powers the whole unit.

The unit features automatic standby after about one hour without a signal (0.4 W in standby versus 20 W in operation). This function can be disabled via a DIP switch for those who prefer to keep the electronics permanently warmed up.

Between Fono MC and Aura: a clear positioning

Compared with the Fono MC MK4 (around €500), the Aos MC adds the symmetrical Class A stage derived from the Aura, Linear Systems FET transistors, and more precise RIAA. Compared with the Aura (more than €4600), it simplifies the topology by moving from three stages to two and adopts a compact chassis rather than a full-width one. The component choices are slightly less expensive, but the core design philosophy remains intact.

For owners of a Rega turntable fitted with an in-house MC cartridge, the Aos MC integrates naturally into the ecosystem. It is also suitable for those who own cartridges from other brands, provided they take the time to set impedance and capacitance according to the cartridge manufacturer’s recommendations.

Technical specifications

Audio design and architecture

• Phono preamplifier dedicated to moving coil (MC) cartridges
• 100% analog architecture, with no digital control circuitry
• Design derived from the reference Aura MC model
• Fully class A two-stage amplification
  • First stage: balanced class A amplifier with ultra-low-noise FET transistors (Linear Systems), ensuring the absence of bias current in the cartridge to preserve its magnetic geometry and signal purity
  • Second stage: class A differential amplifier with a common-base driver stage, providing active amplification of the low-frequency section of the RIAA correction
• RIAA equalization provided by a combination of passive and active networks for maximum precision

Settings and compatibility

• Compatible with a wide range of MC cartridges, especially low-output models
• Impedance setting: 70 / 100 / 150 / 400 Ω
• Capacitive setting: 1000 / 4300 pF
• Selectable gain: +69.3 dB or +63.5 dB

Audio performance

• Frequency response: 17.5 Hz (-3 dB) to 100 kHz (-0.2 dB)
• RIAA accuracy: ±0.2 dB (65 Hz – 70 kHz)
• Total harmonic distortion (THD): 0.03%
• Signal-to-noise ratio optimized thanks to low-noise FET transistors

Power supply and consumption

• Power consumption in operation: 20 W
• Power consumption in standby: 0.4 W
• Automatic standby mode (can be disabled)

Construction

• Custom aluminum chassis in half-width format
• Effective shielding against electromagnetic interference (RFI)
• Streamlined circuit without superfluous components for a direct signal path

Dimensions and weight

• Dimensions (W x H x D): 22 x 8 x 33 cm
• Weight: 2.9 kg

General information

The Rega AOS MC is a phono preamplifier dedicated to moving coil cartridges, designed without compromise to harness the full potential of vinyl records. A direct descendant of the renowned Aura MC, it adopts a fully analog architecture and carefully selected components to guarantee an exceptional level of detail, dynamics, and realism. Manufactured in the United Kingdom, it benefits from a lifetime manufacturer’s warranty covering manufacturing defects.