Rega Research has announced a new adjustable phono amplifier specifically designed for MC cartridges. The new unit, called the AOS MC, is, according to the designers, derived from the Aura, the company's flagship phono amplifier. The cabinet is, of course, black, as is always the case with Rega.
Rega AOS MC
The AOS, from UK-based Rega Research, is, according to its designers, a no-compromise, fully adjustable phono amplifier for moving coil (MC) cartridges. The new device features a circuit design heavily based on the Aura , Rega's reference MC phono amplifier. The AOS is housed in a custom-designed half-width cabinet. Designed for use with a wide range of MC cartridges, the amplifier offers sufficient gain for low-output cartridges and excellent load adjustability, making it the perfect partner for any type of MC cartridge being connected.
The AOS is a fully analog two-stage amplifier without digital control circuits. Its all-aluminum enclosure shields the internal circuitry from disruptive radio frequency interference (RFI). The designers avoided unnecessary components or circuits that could degrade the signal path. The AOS incorporates many innovative design ideas, including a self-regulating servo control that compensates for any variations in ambient or operating temperature.
The AOS uses parallel-connected, low-noise Field Effect Transistors (FETs) configured as a composite pair. Using FETs ensures that no bias current flows through the coil of the cartridge, thus preserving the delicate magnetic geometry of the cartridge.
The MC input allows you to select a resistive input load between 70 and 400 ohms and a capacitive load between 1,000 pF and 4,300 pF. The input sensitivity can be adjusted in 6 dB increments via the rear panel. An automatic standby function has also been added, which puts the unit into sleep mode after a period of no signal. This function can be deactivated via small switches on the rear panel.
Rega OS MC: Analogue two-stage amplifier
The first stage is a symmetrical complementary Class A circuit, using ultra-low noise FET transistors (Field Effect Transistors) from Linear Systems. The use of FET transistors ensures that no bias current flows through the cartridge coil, thus preserving the delicate magnetic geometry of the cartridge. The input circuit configuration also eliminates the use of coupling components between the cartridge output and the input stage FET transistors, which could compromise sound quality. The complementary ultra-low noise FET transistors have been carefully selected and matched for optimal performance.
This stage drives the passive high-frequency portion of the RIAA equalization stage. The complementary ultra-low noise FET transistors have been carefully selected and matched for optimal performance. This stage drives the passive high-frequency portion of the RIAA equalization stage.
The second stage is a symmetrical differential Class A circuit with a common base driver stage. This is also used as an active amplifier in the low-frequency section of the RIAA equalization stage.
Rega claims a frequency response of 17.5 Hz (-3 dB) to 100 kHz (-0.2 dB), and the RIAA curve accuracy is better than ±0.2 dB between 65 Hz and 70 kHz at a 100 kΩ output load. Rega offers a lifetime warranty on its products, including the AOS MC.
Price and delivery information have not yet been announced.
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