Предусилители — Audio Note M8 Line

The M8 Line is a tube line preamplifier from Audio Note (UK), part of an M8 family that also includes the M8 Line Balanced CD Input, M8 Line Signature, M8 Phono, M8 Phono Balanced CD Input, M8 Phono Signature, M8 RIAA and M8 RIAA Signature. As with other M-series models, operation is Class A only, free of negative feedback, with single-ended circuitry. It sits between the M6 and the M9 in the company's range, and it is built as two units of equal size, the audio chassis and an outboard supply chassis.

Key specs that matter

Input impedance is 100K ohms for line signals, and the brand quotes 47K ohms for the phono inputs of the M8 Phono versions. Input sensitivity is 126 mV for 1 V of output. Output impedance comes in under 10 ohms. Each unit is 140 mm high, 440 mm wide and 410 mm deep, and each weighs 16 kg. The mains input accepts AC 100-120 V or 220-240 V at 50/60 Hz. Two front panel finishes are listed, anodised aluminium and black acrylic, for every M8 version.

Engineering and use context

The line stage of the M8 Line uses an ECC82 together with a 6189 and a 6463. Its supply is valve rectified by a 6X5 and is based on the power supply of the M10 Galahad. Compared with the copper parts used lower in the range, the M8 moves to Audio Note (UK) silver wiring and silver foil signal capacitors, combined with tantalum resistors and custom Audio Note electrolytic capacitors. The output transformers are produced in house on a HiB 50% nickel C-core with a silver primary and a silver secondary. In the Signature versions these transformers are fully silver wound and use 55% nickel iron C-cores instead. The M8 RIAA stage, sold separately, carries three 5670 valves, a 6463 line stage and a dual 6X5 rectified supply with an ECL82 for voltage regulation and a 5651 as a voltage stabiliser, while the RIAA version uses two Watt tantalum resistors.

Pairing

The M8 Line has no phono section, so a vinyl source needs an external stage, and the M8 RIAA or M8 RIAA Signature is built for that role. Owners with a balanced CD player can choose the Balanced CD Input version instead, and the low output impedance of the M8 Line lets it feed a power amplifier over a long interconnect.

Alternatives

The Audio Note M6 Line uses an ECC82 and 7044 line stage with output transformers on a UHiB C-core carrying a copper primary and silver secondary, in the same case format.