Goldmund TELOS 153 User manual

USER MANUAL
GOLDMUND TELOS 153
3-channel Power Amplifier

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Thank you for purchasing the Goldmund Telos 153 3-channel Power Amplifier.
You have acquired one of the best Power Amplifiers ever made for professional and
domestic uses.
Please take some time to read this manual. It will provide you with useful information to
make your pleasure of listening to the Telos 153 even higher.
INTRODUCTION
GOLDMUND TELOS 153 –3-channel Power Amplifier
Goldmund was founded in 1978 and has ever since been dedicated to the accurate
reproduction of sound and image.
At Goldmund, we strive to lead in the creation, development and manufacture of the
industry’s most advanced technologies, including audio and video systems, home -
networking and music distribution.
The guiding principle at Goldmund is to produce a precise sound with the least possible
loss of quality through the different stages. Goldmund will never adopt a technology before
it is sufficiently developed to satisfy the high quality standards we set. This is why
Goldmund has often rejected mainstream technologies and developed its own.

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Table of Contents
1UNPACKING 5
2AMPLIFIER LOCATION & COOLING 6
3LINE VOLTAGE ADJUSTMENTS 7
4CONNECTIONS 8
5AMPLIFIER CONTROLS 8
6SOUND QUALITY OPTIMIZATION 9
7SAFETY AND PRECAUTIONS 10
8MAINTENANCE 10
9 TECHNICAL DATA 11
10 GENERAL SAFETY INSTRUCTIONS 13

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W A R N I N G !
No connection or manipulation must be done
before reading these instructions. Damage to
the amplifier may result if the following
instructions are not understood and applied.
These extremely high quality amplifiers
possess new technical features which are a
necessity for accurate sound reproduction in
the best audio systems.
Only careful installation and use can provide
the satisfaction you are expecting.
The installation instructions must be carried
out in full and the mentioned precautions
taken to get the expected result and to avoid
impairing the amplifier’s performance.

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1 UNPACKING
You will find in the GOLDMUND TELOS 153 box:
- The amplifier
- The power cord
- This manual
Please keep the packaging in case you need to transport the amplifier at a later date.
ATTENTION
If you need to return the Telos 153 to the factory or to your local representative for a
warranty repair, please note that it must be repacked in the original packaging.
This packaging has been designed specifically to protect your Telos 153 in transit.
Use of alternative packaging is likely to result in damage, invalidating warranty cover.

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2 AMPLIFIER LOCATION & COOLING
The Goldmund Telos 153 amplifier, like all high quality amplifiers, generates a large
amount of heat when driven at high levels and must be vented properly. It is mandatory to
allow a proper cooling of the heat sinks. Do not put temperature sensitive equipment on top
of the amplifier.
Due to its weight, and to maximize the effect of the built-in "Mechanical Grounding"
construction, the Telos 153 can be located on the floor or on other very strong supports if
they offer rigid transmission to the floor.
The Telos 153 is built on four rubber feet to ensure proper the amplifier support. This
avoids all detrimental vibrations inside the amplifier, following the famous GOLDMUND
"Mechanical Grounding" principle.
If you use more than one Telos 153 at any location, you may decide to stack them. You
may stack up to 3 amplifiers provided extra care is taken to ensure proper air circulation
vents the side heat-sinks.

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3 LINE VOLTAGE ADJUSTMENTS
A voltage selection is provided inside the amplifier.
If your line voltage is not adapted to the voltage indicated on the serial plate of the
amplifier, please consult your local Goldmund dealer for internal adjustment.
ATTENTION
The Goldmund Telos 153 amplifier will function properly for main line voltages indicated
page 11 (see rubric Power for more details).
If your main line is usually out of the tolerance or if you want change the main voltage of
your amplifier, contact your authorized Goldmund retailer to assist you on your request.
Please check the value of the main line fuse. This fuse is located on the back panel of the
amplifier, above the power cord receptacles.
Use an 8A delayed fuse.

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4 CONNECTIONS
Connect the power cord to the back of the amplifier and plug it into the nearest wall plug.
For safety reasons, use only a 3 lugs grounded plug. To obtain the best sound from the
amplifier, avoid any multiple plug or extension cord.
Check if volume control is down to zero on the preamplifier.
Connect the digital input cable to the digital input 1 to 3. Connect the speaker cable to one
of the red and black terminals at the back of the amplifier. Each input has its own output
speaker connector.
You may notice that the ground of the input plug and the black speaker terminal are the
same polarity. The amplifier is non-inverting in phase.
5 AMPLIFIER CONTROLS
On the front plate of the Goldmund Telos 153 amplifier you will find only one POWER key.
As soon as the amplifier is connected to AC line, you can turn on the amplifier by pressing
the power key. When turned ON the channel is connected after a few seconds and the
front panel “POWER” LED lights up.
The amplifier may be powered OFF by turning off the “POWER” switch at any time. The
LED will fade very slowly, indicating discharge of the filter capacitors. The speakers will
be disconnected almost immediately.
When a digital signal is connected in one of the three digital inputs, the orange light will be
turned on indicating that the input is locked.
You might use all inputs simultaneously, each input has is own power amplifier module.

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6 SOUND QUALITY OPTIMIZATION
Warm-up sonic effect
If the power amplifier has not been powered on for a few days, the optimum sound quality
is reached after 15 minutes. This delay has been optimized to be minimal and the sonic
quality when just powered on is much higher than other quality power amplifiers.
Speaker polarity
Even if you have an absolute phase inverter on your preamplifier, and even if you have
carefully selected the proper line phase (see next section), there is a possibility to increase
the sonic quality of your speakers again by reverting the polarity of each speaker cable at
amplifier termination. But since the line phase and the speaker polarity interfere to each
other, you have to experiment carefully with all the combinations before picking the right
one.
If your preamplifier has an absolute phase inverter, this will interfere too. If it does not have
an absolute phase inverter, do not forget the result will depend on the source, as most
records and CDs have been recorded without care for the absolute phase. Be patient…
Mains line phase inversion
The sonic quality of your Goldmund Telos 153 can be greatly improved if the mains AC line
is properly connected. Try to invert the AC plugs of both your amplifiers, using special
adapters.
We recommend that you try this carefully. You must do it in combination with the
speaker polarity and/or with absolute phase switching to be sure of the best result.

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7 SAFETY AND PRECAUTIONS
Protection against DC
The Goldmund Telos 153 is a DC-coupled amplifier without protection. If it is associated
with a badly designed or defective preamplifier the speakers could easily be damaged by
the DC.
The Telos 153 doesn’t amplify DC but DC applied at the input is passed to the output.
This protection circuit is totally transparent and has no sonic effect.
Short-circuits warning
If one output is short-circuited by accident, the amplifier will source too much current.
Such accident should be limited over time to avoid excessive heat. Short-circuits are not
covered by the warranty.
ATTENTION: the Goldmund Telos 153 is an extremely high speed amplifier.
Any bad ground connection can generate high frequency oscillations which are dangerous
for the tweeters.
It is also generally dangerous to run input cables and speaker cables in parallel for a long
distance. If these cables are not of high quality or badly shielded, an “Antenna-Effect” can
generate dangerous high-frequency oscillations.
8 MAINTENANCE
The Goldmund Telos 153 amplifier usually requires no maintenance.
To clean your amplifier, use a very soft, clean, damp cloth to avoid scratching the surface.
Dampen with water or a mild detergent solution. Avoid abrasive or harsh cleansers (e.g.
products containing sodium carbonate). Always turn the power OFF before cleaning your
amplifier.