Предусилители — Audio Note M6 Line

The M6 Line is a two-box valve line preamplifier from Audio Note (UK), with the audio circuit in one chassis and its power supply in a second one of the same size. It belongs to the M3 family, in which the M3, M5, M6 and M8 share one circuit topology and differ in the grade of parts, level by level. The M6 is built to Audio Note's Level 4 criteria and is offered as the M6 Line, the M6 Line Balanced CD Input, the M6 Line Signature, the M6 Phono, the M6 Phono Balanced CD Input and the phono-only M6 RIAA. Buyers choose between an anodised aluminium and a black acrylic front panel.

Key specs that matter

Its line stage runs on an ECC82 and a 7044. Line input impedance is 100 kOhm, input sensitivity is 126 mV for 1 V output and output impedance is below 10 ohm. Both the preamplifier and the power supply measure 140 mm high, 440 mm wide and 410 mm deep and weigh 16 kg each. Mains input is 100 to 120 V or 220 to 240 V at 50 or 60 Hz. The 47 kOhm phono input figure applies only to the Phono versions, which add three 5670 valves in the phono stage, each version with its own dedicated valve-rectified supply.

Engineering and use context

The circuit is single-ended, runs in pure Class A and uses no negative feedback. The separate supply is based on the M10 Galahad design, with a 6X5 valve rectifier, an ECL82 for voltage regulation and a 5651 as a voltage stabiliser. Housing the supply in its own case puts its transformer and valves at a distance from the low-level audio circuit. Wiring is Audio Note silver, and the parts list includes 1 W Audio Note tantalum resistors, custom electrolytic capacitors and Audio Note copper foil signal capacitors. The output is taken through in-house custom transformers wound on a UHiB c-core with a copper primary and a silver secondary. Instead of separate volume and balance potentiometers, each channel has its own Audio Note stepped attenuator, which sets level and balance in fixed steps. A balanced output circuit sits alongside the single-ended outputs.

Pairing

The low output impedance lets the M6 Line work into power amplifiers with low input impedance, including balanced designs such as the Audio Note Ginrei monoblocks with their 2.4 kOhm XLR input. Vinyl users need either a Phono version or an external phono stage.

Alternatives

The Audio Note M8 Line is the Level 5 member of the same family, with an ECC82 or 6189 and 6463 line stage and silver foil signal capacitors.