Rega AOS MC Phono Preamplifier, black

Rega AOS MC Phono Preamplifier, black

AOS MC

The AOS is a “purely analog amplifier” without digital control circuits. The housing, made entirely of aluminum, shields the internal circuitry from interference (RFI). Rega developers have deliberately avoided unnecessary components or circuits that could interfere with the signal path.

The AOS incorporates numerous innovative design ideas, including a self-adjusting servo control that compensates for fluctuations in ambient or operating temperature. The AOS uses low-noise FETs (field effect transistors) connected in parallel and configured as a composite pair. The use of FET transistors ensures that no bias current flows through the pickup coil, thus preventing any interference with the pickup's sensitive magnetic geometry. The MC input allows the selection of resistive loads between 70 Ω and 400 Ω as well as capacitive loads between 1000 pF and 4300 pF. The input sensitivity can be adjusted by 6 dB via the rear panel.

First amplifier stage

The first stage is a balanced, complementary Class A amplifier that uses Linear Systems Ultra Low Noise FET transistors. By using FET transistors, no bias current flows through the pickup coil, so as not to interfere with the sensitive magnetic geometry. The input circuit does not require coupling capacitors between the pickup output and the FET input transistors, thus avoiding sound-impairing influences. The complementary Ultra Low Noise FET transistors are carefully selected and matched to ensure optimal performance. This stage drives the passive high-frequency part of the RIAA equalization.

Second amplifier stage

The second stage is a balanced Class A differential amplifier with a driver stage in a base circuit; this also serves as an active amplifier in the low-frequency section of the RIAA equalization.

Specifications

• Phono preamplifier for MC systems
• Fully adjustable load matching
• Factory preset for all Rega MC cartridges
• Circuit design based on the Aura MC reference stage
• Custom-made aluminum housing in half standard format
• Lifetime warranty against manufacturing defects
• Input load: 70, 100, 150 & 400 Ω
• Capacitive load: 1000, 4300 pF
• RIAA accuracy (100 kΩ output load): better than ±0.2 dB from 65 Hz to 70 kHz
• Frequency response: 17.5 Hz (3 dB) to 100 kHz (0.2 dB)
• Input sensitivity: 69.3 dB (gain setting I), 63.5 dB (gain setting II)
• Power consumption in standby mode: 0.4 W | Power consumption: 20 W
• Dimensions (W×H×D): 220 × 80 × 330 mm
• Weight: 2.9 kg