Фонокорректоры — Audio Note M9 RIAA

The M9 RIAA is a standalone valve phono stage from Audio Note UK of Hove, England, built as two full-size boxes - one for the audio circuit and one for its supply. Audio Note ranks the M9 family at Level 5 of its internal grading system. The M9 name covers four versions - M9 Phono, M9 Phono Signature, M9 RIAA and M9 RIAA Signature - and the RIAA variants drop the line section to act purely as a phono equaliser.

Key specs that matter

The stage is designed for moving-magnet cartridges and loads them with 47,000 ohm. Its output impedance stays below 10 ohm, and RIAA equalisation is held flat within plus or minus 0.1 dB. Each chassis is 140 mm high, 440 mm wide and 410 mm deep, and the two boxes add up to 30 kg. Maximum mains draw is quoted at 81 W, and the supply accepts 100-120 V or 220-240 V at 50/60 Hz.

Engineering and use context

Audio Note keeps the whole signal chain single-ended, biased in pure Class A and free of any negative feedback loop. Audio Note builds the equalisation around what it calls a Virtual Component - a specially wound transformer with a nickel-iron core and silver wire sits at the centre of the RIAA network, and its inductance becomes part of the correction curve in an inductor, capacitor and resistor arrangement. The company states that this removes stray capacitance and lets the network run at around 50,000 ohm instead of the usual 600 ohm. The input valve is a Philips SQ E80F pentode, followed by an E80CC double triode. Input and output transformers use 55 percent nickel-iron cores with silver windings, and the output transformer provides both unbalanced and balanced connections. Silver foil capacitors appear throughout, and the parts are hard-wired on phenolic-treated wooden boards. Valve rectification and valve regulation live in the separate supply box and reach the main unit through umbilical cables.

Pairing

Because Audio Note describes the M9 RIAA as a moving-magnet stage, any low-output moving-coil cartridge has to be raised to MM level by a step-up transformer first, and the brand makes its own S9 unit for exactly that job. The transformer-coupled output with RCA and XLR sockets can feed either an unbalanced or a balanced line preamplifier.

Alternatives

Within the same brand, the M8 RIAA is another valve phono stage in the Audio Note range for vinyl owners who want a dedicated equaliser.