M2 Phono
Owner’s Information
The M2 Phono is a Level 2 phono pre-amplifier,
developed for the best possible sonic performance rather
than technical specifications. To this end, the M2 Phono
incorporates thermionic valve technology to produce the
most accurate sound possible and has been brought to
maturity through a development process we call
comparison by contrast, which is currently unique to
Audio Note. The article from which this technique is
based, named ‘Audio Hell’, is available from Audio
Note by request.
Please read this manual carefully in order to obtain the
best possible performance from your pre-amplifier.
Audio Note wishes you many happy years of listening
pleasure.
Technology
It is well known to any audio circuit designer worth their salt that accurate
reproduction of music relies entirely on the preservation of the purity of the incoming
signal. It is therefore not a difficult step to make to realise that the complexity of the
circuitry itself must be kept to a minimum in order to retain the musicality of the
original performance.
In response to this, all Audio Note pre-amplifiers use a single-ended, zero feedback
circuit topology. The single-ended gain stage topology is simply the most linear,
demanding pure Class A valve operation and removing the need for a phase splitter,
which introduces unnecessary crossover distortion.
The Audio Note amplifier range does not make use of any kind of feedback. As a
result, they were neither designed for vanishingly small harmonic or low
intermodulation distortions, but instead for minimal non-harmonic and time base
anomalies. It is these non-harmonic amplitude and time base distortion that have a
highly perceptible and adverse affect on the signal waveform.
Our amplifiers are designed for maximum linearity without ‘corrective’ measures to
keep transient distortions to a minimum rather than introducing the recursive errors
inherent in feedback loops.
The M2 Phono features a 6SN7 line stage, an ECC83 and ECC88 phono stage, and a
valve rectified power supply
Unpacking & Installation
Please take care when unpacking the pre-amplifier. We recommend that you store the
packing materials in case the unit requires shipping at a later date.
Next, select a suitable location for the unit, ensuring that adequate ventilation is
provided (the valves generate a fair amount of heat). In the interest of safe, reliable
operation, situate the pre-amplifier well away from dampness or direct sunshine.
Avoid sitting the M2 Phono close to any other equipment, such as a power amplifier,
that may be generating a strong magnetic field, or in close proximity to active mobile
telephones.
Worthwhile sonic improvements may be obtained by locating the unit on a
specifically designed audio component support system; we tend to prefer natural
materials such as wood.
The M2 Phono is capable of driving long interconnects to power amplifiers and so, if
you are using mono block amplifiers, it may be worthwhile to locate them close to the
speakers. This will reduce the speaker cable lengths and provide sonic improvements.
Connections
Please ensure that the M2 Phono, the power amplifier and any source equipment is
switched off before making any connections.
NOTE: It is important that all connections are firm, secure and airtight; any
oxidisation of the interconnects will result in loss of performance. Always use high
quality interconnects; Audio Note interconnects are recommended, as they are
manufactured to the same exacting standards as all of our products.
Inputs
The M2 Phono offers three standard unbalanced line inputs, one phono input and a
tape input. The inputs each consist of a pair of RCA connectors, one red and one
white, for right and left channels respectively.
The line inputs and tape input are suitable for connection to any line level source
equipment, such as a CD or DVD player.
The phono input is suitable for connection to a turntable with a moving magnet (MM)
type cartridge. Turntables with moving coil (MC) type cartridges will require a stepup transformer between the turntable and the pre-amplifier; Audio Note produce some
of the best step-up transformers available.
Outputs
The M2 Phono provides two unbalanced outputs and a tape output. Again, all of these
outputs consist of a pair of colour coded RCA connectors.
The two main outputs are for connection to a power amplifier and are identical,
making them suitable for biwiring.
The tape output is routed directly from the input selection switch; this provides a
suitable level for recording. The tape input is not routed to the tape output.
Feedback switches
Two feedback switches are located next to the ground terminal on the rear panel.
These are used for matching the pre-amplifier to the rest of your system. Set the
switches to the 'on' position if any of the following apply, when in doubt, choose the
setting that provides the best sonic performance:
• If the volume control is too sensitive.
• If the interconnects between the pre-amplifier and the power amplifier are
longer than 3 metres.
• If your amplifier has an input impedance of less than 50kO
NOTE: Always turn the power off before adjusting the feedback switches. Ensure that
both feedback switches are in the same position.
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