Audio Note M1 RIAA User Manual

M1 RIAA

Owner’s Information

The M1 RIAA is a Level 1 RIAA phono stage,
developed for the best possible sonic performance rather
than technical specifications. To this end, the M1 RIAA
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 M1 RIAA features an ECC83 and ECC88 phono stage and an improved version
of the zero 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 M1 RIAA 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.

Connections

Please ensure that the M1 RIAA, 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 M1 RIAA has one phono input, which consists of a pair of RCA connectors,
colour coded red for the right channel and white for the left channel.

The 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 step-up
transformer between the turntable and the pre-amplifier; Audio Note produce some of
the best step-up transformers available.

Outputs

The M1 RIAA provides two unbalanced outputs; again, these outputs consist of a pair
of colour coded RCA connectors. The two outputs are for connections to a line level
pre-amplifier and are identical, making them suitable for biwiring.

Ground Post

A ground connection is provided to assist in the elimination of any ground loops that
may occur. A ground loop can be identified by excessive background hum. If you
experience a ground loop, try connecting the ground connection with that of other
system components. If the hum persists, contact your dealer.

Mains Power

An IEC power connector is located on the back of the M1 RIAA. Use the supplied
power cable to connect the pre-amplifier to the mains supply. Ensure the power is off
at the switch when you do this.