Audio Note KASSAI Balanced Technical manual

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KASSAI
Balanced
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MONO POWER AMPLIFIERS
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OWNER’S 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) VALVE INSTALLATION
8) CONNECTION
10) OPERATION
11) TECHNICAL SPECIFICATIONS
12) WARRANTY INFORMATION
13) CONTACT INFORMATION
CONTENTS
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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 !
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 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.!
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 must be earthed –ensure that the mains supply cable earth /
ground is correctly connected.
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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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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) KASSAI Balanced mono
power amplifiers.
They are Pure Class A Parallel Singled Ended valve amplifiersthat use a pair of the
highly regarded 300B triode valves per channel, producing a level of performance
that is radically superior to the vast majority of current designs.
They have been specifically engineered for sonic performance rather than technical
specification, and fulfill all Audio Note (UK) Level 4 criteria: -
Pure Class A operation
Zero Negative Feedback
Single Ended Output Stage
Valve Rectification
Directly Heated Triode operation
Materials and component quality
Each KASSAI Balanced amplifier is equipped with input and output transformers that
are unparalleled in design, quality and performance at this price point in the field of
Audio reproduction.
The balanced / XLR input transformers are hand wound by Audio Note (UK), and
feature a copper primary and Silver secondary. The core material is of the highest
quality, to offer the finest possible signal path from your preamplifier.
The output transformers are similarly specified, with a copper primary and Silver
secondary. The cores are our own Double C design and are manufactured from our
own UHiB material. As would be expected, they are custom designed and
manufactured by us, in house in the U.K.
As is expected of an Audio Note (UK) Level 4 product, each amplifier is equipped
with valve rectification, supplied by a selected 5U4GB valve.
KASSAI BALANCED MONO POWER AMPLIFIERS

Please take care when unpacking your KASSAI Balanced amplifiers. Choose a
clean, clear location to unpack them, and be aware that the amplifiers are very
heavy; before attempting to unpack or lift the units, check the weight and if necessary
use more than one person so that they 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 amplifiers. 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 supporting the weight of the units.
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 amplifiers is provided, and that airflow
through any ventilation slots in the casework is not restricted. We recommend a
distance of at least 50cm free space is maintained above the amplifiers, and
preferably they should be sited in free space or on the top shelf of your equipment
rack or table. Please also remember that valve equipment operates at extremely high
temperatures, so a position that is inaccessible to any children or animals is
essential.
UNPACKING AND INSTALLATION

The amplifiers are shipped without their valve compliment installed. It is necessary to
install the valves before operation.
It is essential that the valves are installed correctly or serious damage that is not
covered by the warranty will result. We recommend that your dealer perform
this procedure for you if you are in any way unsure.
FIRSTLY, ENSURE THAT THE AMPLIFIERS ARE NOT CONNECTED TO A MAINS
ELECTRICAL SUPPLY, AND THAT THE POWER CORDS ARE NOT CONNECTED
TO THE AMPLIFIER.
Remove the top covers from the amplifiers. There are a total of 20 screws used to
secure this cover on EACH chassis.
Now remove the valves that are packed separately and carefully unwrap them. Also
inspect the amplifiersto check that nothing has become damaged or dislodged
during transit.
In the above drawing, the positions of the valves are marked in RED.
VALVE INSTALLATION
300B
valves
6SN7
valve
5U4GB
valve
Mains Input
Transformer
FRONT OF AMPLIFIER
REAR OF AMPLIFIER
XLR INPUT
MAINS INPUT

You should find the following valves: -
2 x 6SN7 input stage valves
4 x 300B output valves
2 x 5U4GB rectifier valves
Once again, please understand that it is absolutely vital these valves are fitted
correctly.
Looking from the front of the amplifier install the 300B valves first. Inspect a 300B
and you will notice that two of the metal pins located at the bottom of the valve are
larger than the other two; this is to help ensure that the valve can only be inserted
one way.
Now examine the large valve sockets located at the rear of the central circuit board of
each amplifier (refer to drawing on previous page). You will notice that two of the four
holes in each valve socket are larger than the others. Line up the large pins on the
bases of the 300B valves and the large holes in each valve socket, and with gentle
but firm pressure insert each valve into its socket.
Next, examine the 6SN7 valves. You will see that there is a rib on the central pin of
the valve, which ensures that it can only be inserted into the valve socket correctly.
Insert these valves into the sockets located at the front of the central circuit board in
each amplifier (refer to drawing on previous page). Locate this rib and align with the
corresponding aperture in the centre of the valve socket. With gentle but firm
pressure,insert the valve.
Next, examine the remaining 5U4GB rectifier valves. You will see that there is a rib
on the central pin of the valve base, which ensures that it can only be inserted into
the valve socket correctly. Locate this rib and align with the corresponding aperture in
the centre of the valve socket, located on the right hand circuit board of each
amplifier, in front of the mains inlet transformer (refer to drawing on previous page).
With gentle but firm pressure,insert the valve.
Check one more time that all of the 8 valves are correctly fitted!
VALVE INSTALLATION continued…

Line inputs Being mono power amplifiers, each KASSAI Balanced is fitted with a
single XLR / Balanced input. Looking from behind the amplifiers, they
are located at the top / right hand side of the rear panels. Connect the
outputs from your preamplifier to these inputs.
If your preamplifier is equipped with RCA / Single Ended outputs only,
please refer to the ‘Cable Configuration Options’ information on the
following page.
Speakers Each amplifier is equipped with 3 colour coded binding posts for
connection to your speakers.
Looking from the rear of the amplifiers, the 3 binding posts are located
at the centre of the rear panels.
Connect the amplifiers black speaker output binding post marked as
“0” to the black / negative terminal (also marked “ –“) on the
loudspeaker.
Connect the amplifiers red speaker output binding post marked “8
Ohm” to the red / positive terminal (also marked “ + “) on the
loudspeaker. The other red output binding post is marked “4 Ohm”
and may be used with 4 Ohm speakers. If you are uncertain whether
your speaker system is specified as 4 or 8 Ohm, try the following test
once all other connections are made and the amplifier is operational.
Compare the sound quality using a familiar recording with the
speakers connected to the 8 Ohm connections and then the 4 Ohm
connections respectively. The combination that produces the best
frequency balance and maximum dynamics should be used.
Mains Each KASSAI Balanced is equipped with an IEC 320 mains inlet
socket, located at the top / left hand side of the rear panel. Use the
supplied mains cablesto connect the unitsto the local mains supply.
The two fuses are located in the two fuse holders, located on the rear
panel beneath the ‘speaker binding posts.
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.
CONNECTION

CONNECTION continued…
CABLE CONFIGURATION FOR RCA SINGLE ENDED
PREAMP OUTPUT TO XLR BALANCED AMPLIFIER INPUT
2
1
3
SCREEN
XLR MALE
RCA MALE
PREAMP OUTPUT
KASSAI INPUT
SCREEN CONNECTED AT PREAMP END ONLY, TO
ELIMINATE GROUND LOOPS
3
2
1
2
1
3
SCREEN
XLR FEMALE
XLR MALE
PREAMP OUTPUT
KASSAI INPUT
CONVENTIONAL: SCREEN CONNECTED AT BOTH ENDS
XLR FEMALE
XLR MALE
3
1
1
2
2
3
SCREEN
PREAMP OUTPUT
KASSAI INPUT
CABLE CONFIGURATION OPTIONS

Once all the connections are completed and checked, ensure that the volume control
of your preamplifier / source is at the minimum setting.
Turn on all components in the signal chain BEFORE the KASSAI Balanced; they
should always be the LAST components to be switched ON, and the FIRST to be
switched OFF.
Turn on the amplifiersby using the rocker switch located on the rear top left of the
back panels, just above mains inlet socket.
Bedding in The new amplifiers requires about 100 hours of initial use
(called “bedding in”) before the circuitry becomes stable and
optimum performance is realized.
As the amplifiers “bed in” the sound will become increasingly
smoother, detailed and open.
Once the amplifiers have “bedded in” a warm up time of
approximately 30 to 45 minutes is required each time the
amplifiers are switched on before optimum sonic performance
is reached.
Cleaning No special maintenance is required for the amplifiers. 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 amplifiers.
ENSURE THAT THE AMPLIFIERS ARE SWITCHED OFF
AND DISCONNECTED FROM THE MAINS ELECTRICITY
SUPPLY BEFORE UNDERTAKING ANY CLEANING.
Valve Life The valves supplied with your amplifiers should provide
approximately 6000 hours of operation. They are specially
selected by us, and should only be replaced with matched
pairs. Please consult your Audio Note (UK) dealer should your
valves need replacing.
OPERATION

TECHNICAL SPECIFICATIONS
INPUT IMPEDANCE
INPUT SENSITIVITY
MAXIMUM OUTPUT
CHANNEL BALANCE
VALVE COMPLIMENT
UNIT WEIGHT
SHIPPING WEIGHT
(ORIGINAL PACKAGING)
UNIT DIMENSIONS
SHIPPING DIMENSIONS
(ORIGINAL PACKAGING)
MAINS INPUT
MAINS FUSE
MAX. POWER
CONSUMPTION
NOTE
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600 Ohm
1.6V for full output
18 watts RMS per channel into 4 or 8 Ohm
loads
+/-0.3dB
2 x 5U4GB
4 x 300B
2 x 6SN7
25KG (per amplifier)
35KG (per amplifier)
220mm (h) x 460mm (w) x 530mm (d)
420mm (h) x 650mm (w) x 670mm (d)
AC 100-120V/220-240V 50/60 Hz
3.5A Anti Surge (110/120V Supply)
1.6A Anti Surge (200/240V Supply)
400mA (Internal HT)
200 Watts
Due to Audio Note (UK)’s ongoing
research and development program,
specifications are subject to change
without notice.
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Audio Note (UK) warrants this product to be free from defects in materials and
workmanship for two yearsfrom the original date of purchase from an appointed
Audio Note (UK) dealer, and agrees to cover the cost of parts and associated labour
required to correct such defects, subject to terms & conditions.
This Warranty is offered to the first purchaser only.
Any valves supplied with the unit are warranted for three months from the original
date of purchase.
If the product fails in normal domestic use and during the Warranty period due to the
above described faults or defects, Audio Note (UK) will,at its discretion, repair or
replace the item free of charge within a reasonable time once it has been returned to
Audio Note (UK) or an appointed Audio Note (UK) dealer or service engineer.
Audio Note (UK) is not liable for any shipping charges incurred whilst transporting the
product to or from Audio Note (UK) or an appointed Audio Note (UK) dealer or
service engineer, should the item require service or repair during or after the
Warranty period.
If the product must be shipped, please use the original packaging materials and
include a copy of the original sales receipt along with a note explaining, in as much
detail as possible, the problems you are experiencing with the unit.
Only use a reputable Courier Service or Shipping Agent, and ensure that your
product is insured during transit.
Any servicing, repairs or modificationsnot authorized by Audio Note (UK), or
carried out by persons other than appointed Audio Note (UK) service
engineers will invalidate any warranty.
This Warranty does NOT cover: -
Damage sustained whilst in the possession of a shipping agent, retailer or consumer
and not caused as a direct result of defects in materials or workmanship.
Damage caused by normal wear and tear.
Damage or defects caused by abnormal or unreasonable use.
Damage caused by accident, acts of nature, misuse or neglect.
Damage caused by a failure to follow the operating and installation instructions
supplied with the product.
Damage caused by improper or careless cleaning.
Audio Note (UK) reserves the right to refuse warranty for any component of which
the serial number has been removed, defaced or tampered with.
WARRANTY INFORMATION

Audio Note (UK) Limited
25 Montefiore Road
Hove
East Sussex
BN3 1RD
United Kingdom
Tel: [phone]
Fax: [phone]
e-mail: [email protected]o.uk
CONTACT INFORMATION
If in the future your Audio Note (UK) product
requires servicing, or if you require technical support
or have any questions regarding this or any of our
other products, please contact your local Audio Note
(UK) dealer.
Alternatively, please feel free to contact us directly: -!