Audio Note M2 RIAA Technical manual

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M2 Line
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PRE AMPLIFIER
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OWNERʼS INFORMATION
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1) IMPORTANT SAFETY INFORMATION
2) CE DECLARATION OF CONFORMITY
DISPOSAL
POWER REQUIREMENTS
3) INTRODUCTION
4) OVERVIEW
5) UNPACKING AND INSTALLATION
6) CONNECTION
7) OPERATION
9) TECHNICAL SPECIFICATIONS
10) WARRANTY INFORMATION
11) CONTACT INFORMATION
CONTENTS
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OTHER SAFETY PRECAUTIONS: -
Never touch the power cord with wet hands.
Always remove the power cord by grasping the plug, not the cable.
Never expose the unit to excessive heat or magnetism.
Never let an inexperienced person repair or reassemble the unit.
Never put anything, especially metal objects, inside the unit.
Never place excessive weight on the unit.
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Do not store or operate this unit in areas of high humidity or in close
proximity to water / moisture.
Do not expose or immerse the unit in liquid of any kind.
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This product generates high levels of heat. Adequate ventilation must
be provided. Do not restrict airflow through any ventilation slots or
place the unit on any surface that may restrict airflow.
Valve equipment operates at extremely high temperatures;
KEEP OUT OF THE REACH OF CHILDREN AND ANIMALS.!
RISK OF SHOCK OR ELECTROCUTION! INTERNAL OPERATING
VOLTAGES ARE LETHAL!
Do not remove top cover, unless specifically instructed to do so in the user
manual.
This unit contains fuses and other safety components in accordance with
BS60065 requirements.
In the event of failure, replacement fuse or safety component must be of
the same part type and value.
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This product must be earthed –ensure that the mains supply cable earth /
ground is correctly connected.
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SUCH REPLACEMENT MUST ONLY BE CARRIED OUT BY A
QUALIFIED SERVICE TECHNICIAN.
Do not attempt to replace any fuses without first disconnecting the unit
from the mains electricity supply.
! IMPORTANT SAFETY INFORMATION !

POWER REQUIREMENTS
Power requirements for electrical equipment vary depending on your geographical
location. Please ensure that your unit meets the power requirements in your area.
The power requirement for your unit is marked on the serial number plate, located on
the rear panel.
If you are in doubt, please contact your dealer before plugging the unit into the mains
supply.
CE DECLARATION OF CONFORMITY
DISPOSAL
This product must not be disposed of as normal household waste. To
prevent possible harm to the environment please separate the product
from other waste to ensure that it can be recycled in an environmentally
safe manner. Please contact your retailer or the appropriate local
government office for collection facilities.
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We declare under our sole responsibility that this product is in conformity
with the following standards or standardized documents:
BS EN 60065 in accordance with the regulations 73/23/EEC, 89/336/EEC
(from 1 January 1997)
CE 94
Peter Qvortrup,
Director
Audio Note (UK) Limited
25 Montefiore Road
Hove
East Sussex
BN3 1RD
United Kingdom
Tel: [phone]
Fax: [phone]
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Thank you for purchasing this Audio Note (UK) product. With the correct care it
should give you many years of pleasure and enjoyment.
Please take the time to read all of the information in this manual before connecting
your new component to an electrical supply or your system, to ensure both your
safety and satisfaction.
Please note that due to our desire to continually improve products, specifications are
subject to change without notice. Therefore it is important to refer to the manual that
is supplied with your product for the most accurate information; manuals downloaded
from our website or obtained from other sources may no longer fully apply to your
product.
If you have any questions regarding the information contained within this document
or your new component, please feel free to contact us: -
Audio Note (UK) Limited
25 Montefiore Road
Hove
East Sussex
BN3 1RD
United Kingdom
Tel: [phone]
Fax: [phone]
e-mail: [email protected]o.uk
INTRODUCTION

Congratulations on your purchase of the Audio Note (UK) M2 Line Pre Amplifier.
It has been specifically engineered for sonic performance rather than technical
specification, and fulfills all Audio Note (UK) Level 2 criteria: -
Pure Class A operation
Zero negative feedback
Single Ended circuit topology
Valve rectification
Materials and component quality
It is well known that the accurate reproduction of music, not just sound, requires the
purity of the incoming signal to be preserved. It is therefore not difficult to conclude
that, in order to achieve this goal and to retain the musicality of the original
performance,the complexity of the circuitry itself must be kept to a minimum.
In response to this, the M2 Line Pre Amplifier uses a single-ended, zero feedback
circuit topology. This is simply the most linear design possible, demanding pure
Class A valve operation and removing the need for a phase splitter, which introduces
unnecessary crossover distortion.
In contrast to the majority of the audio industry, we design our circuits with the aim of
minimising non-harmonic and time base anomalies, rather than producing
vanishingly small harmonic or low intermodulation distortion measurements. These
non-harmonic amplitude and time base distortions have a highly perceptible and
adverse affect on the signal waveform, and it is far more important to address these
factors than participate in the increasingly irrelevant numbers game that chases
ʻperfect measured responseʼ.
As a result, the M2 Line was designed for maximum linearity and minimum transient
distortion, and avoids the need for detrimental ʻcorrectiveʼmeasures, such as
inherently error-prone feedback loops.
The M2 Line Pre Amplifier features a 6SN7 line stage and a valve rectified power
supply incorporating a 6X5 and an ECL82.
M2 LINE PRE AMPLIFIER

Please take care when unpacking your M2 Line Pre Amplifier. Choose a clean, clear
location to unpack your unit. Be aware that the Pre Amplifier is quite heavy; before
attempting to unpack or lift the unit, check the weight and if necessary use more than
one person so that it can be moved safely and easily.
We recommend that you retain and carefully store all of the original packing
materials, in case transportation / shipping is required at a later date.
Select a suitable location for the unit. This should be a dry, dust free and level area,
preferably shielded from direct sunlight and free from vibration. Also ensure that the
location is stable and capable of carrying the weight of the unit.
A suitable mains power outlet must be close to the location; power cords must not be
pulled or stretched tightly in an attempt to reach a wall socket. If the power cord will
not easily reach the socket, choose a closer location!
Please ensure that adequate ventilation for the unit is provided, and that airflow
through any ventilation slots in the unit is not restricted. We recommend a distance of
at least 20cm free space is maintained above the unit. Please also remember that
valve equipment operates at extremely high temperatures, so a position that is
inaccessible to children or animals is essential.
UNPACKING AND INSTALLATION

Line inputs Four line inputs are available labeled CD1, CD2,Tuner and Aux. Any
standard ʻline levelʼsource can be connected to these inputs.
Connect the ʻRec-Outʼor ʻLine Outʼsockets on your recording device
to the ʻTape Inʼsockets of the M2 Line, and the ʻTape Outʼsockets to
the ʻRec-Inʼor ʻLine Inʼsockets of your recording device.
Ground Post A ground post is provided for connection to those source components
that also use a separate ground terminal.
Mains The M2 Line Pre Amplifier utilizes an IEC 320 mains inlet socket. Use
the supplied mains cable to connect the unit to the local mains supply.
The mains fuse and a spare is located in the inlet socket fuse drawer.
Special Note –Make sure that all connectionsare tight and clean. For
best results use good quality audio interconnects. Although it is
perfectly acceptable to use cables manufactured by other companies,
for best results and performance, we recommend our own Audio Note
(UK) range of interconnects and loudspeaker cables. For further
information, please consult your nearest Audio Note (UK) dealer, or
alternatively please feel free to contact us directly.
Outputs The M2 Line provides two unbalanced outputs, consisting of two pairs
of colour coded RCA / Single Ended sockets. RED is for RIGHT
channel connection, WHITE is for LEFT channel connection.
RCA The two pairs of RCA / Single Ended outputs are for connection to a
power amplifier and are identical, making them suitable for bi-amping.
CONNECTION
RCA SOCKET,
CENTRE = POSITIVE / SEND.
RCA SOCKET,
SHELL = NEGATIVE / RETURN.

OPERATION
Once all the connections are completed and checked, ensure that the volume control
is at the minimum setting (rotated all the way left).
Ensure that all source components connected to the M2 Line Pre Amplifier are
switched ON. Source components should always be the FIRST components to be
switched on and the LAST components to be switched off.
Ensure that all power amplifiers connected to the M2 Line Pre Amplifier are
switched OFF. Any power amplifiers in use should be the LAST components to be
switched on, and the FIRST components to be switched off.
The above procedure minimizes the possibility of loud noises produced by
components at switch on being passed to the loudspeakers and possibly causing
damage.
Turn on the M2 Line Pre Amplifier by using the rocker switch located on the rear
panel, above the mains inlet IEC socket.
The M2 Line Pre Amplifier requires approximately 45 seconds to initialize before it is
ready for operation.
Input Selector Turn the selector to the source you wish to listen to.
Source / Tape This allows you to switch between the selected source input
and the output of your recording device.
Volume Control This control adjusts the listening level, or loudness. Set as
desired!
Balance Control This control adjusts the relative left/right levels. Use this control
if necessary to equalize the loudness from each speaker.
Feedback
Switches Two feedback switches are located next to the ground terminal
on the rear panel; these are used for matching the output of the
M2 Line to the input of the following power amplifier.
Set the switches to the ʻonʼposition if any of the following
apply: -
The volume control is too sensitive, and output is too high.
If the interconnects between the M2 Line and the following
power amplifier are longer than 3 meters.
If the power amplifier has an input impedance of less than
50KOhms.
When in doubt, choose the setting that provides the best sonic
performance.
NOTE: Always turn the power off before adjusting the feedback switches. Ensure
that both feedback switches are in the same position.

Bedding in The new preamplifier requires about 200 hours of initial use
(called “bedding in”) before the circuitry becomes stable and
optimum performance is realized.
As the preamplifier “beds in” the sound will become
increasingly smoother, detailed and open.
Once the amplifier has “bedded in” a warm up time of
approximately 30 to 45 minutes is required each time the
amplifier is switched on before optimum sonic performance is
reached.
Cleaning No special maintenance is required for the amplifier. Use a
soft, clean lint free cloth to remove any surface marks from the
casework. For finger marks / grease, use a soft, clean lint free
cloth, lightly moistened with a solution of warm water and mild
detergent. Do not use any alcohol or solvent based cleaning
products, as they may damage the finish of the amplifier.
ENSURE THAT THE M2 LINE IS SWITCHED OFF AND
DISCONNECTED FROM THE MAINS ELECTRICITY
SUPPLY BEFORE UNDERTAKING ANY CLEANING.
Valve Life The valves supplied with your M2 Line Premplifier should
provide approximately 5 years of operation. They are specially
selected by us, and should only be replaced with valves of the
same type and specification. Please consult your Audio Note
(UK) dealer should your valves need replacing. Alternatively,
feel free to contact us directly.
OPERATION continued…