ALLNIC AUDIO KT-150 User manual

A-2000 25TH ANNIVERSARY
KT150 STEREO POWER AMPLIFIER
OWNER’S MANUAL

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OWNER’S MANUAL
A-2000 25TH ANNIVERSARY
KT150 STEREO POWER AMPLIFIER
Thank you for purchasing the Allnic Audio A-2000 25TH ANNIVERSARY
KT150 STEREO POWER AMPLIFIER. We are certain your trust in Allnic Audio
and Audiomentors, as well as your appreciation for the sound of this high-
quality device, will be rewarded by its excellent operation for years to come.
AUDIOMENTORS(ALLNIC AUDIO’S MARKETING COMPANY)
3f. GanaPlaza, 8-3 Sunae-dong, Bundangdong, Gyeonggy-do
South Korea
Direct Telephone: [phone]
email: [e-mail]
Website: www.audiomentors.co.kr
** Information and specifications for the Allnic Audio product described
in this manual are subject to change without notice.

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Please read about SAFETY before you attempt to use the A-2000 25TH
ANNIVERSARY - we care about our customers and the equipment, and we
want you to enjoy this product for a long time!
INTRODUCING THE A-2000 25TH ANNIVERSARY
STEREO POWER AMPLIFIER
The A-2000 25th anniversary stereo power amplifier
is Allnic Audio’s only KT150 stereo power amplifier
model. Like all Allnic Audio products, the A-2000
25th anniversary has Permalloy (iron and nickel alloy)
for its transformer cores. Allnic is grateful to Mr.
G.W. Elmen of Western Electric for inventing
Permalloy for transformer core use, and in so doing,
providing an enormous service to recorded music
listeners everywhere.
The 2000 25th anniversary has the following
features:
•100 watts of high power output. The A-2000
25th anniversary is a push-pull, triode/pentode
switchable power amplifier. Powerful
Driving Circuitry. Allnic believes in the
importance of using high-quality, low noise
and powerful driving circuitry in all its
amplifying devices. Therefore, in the A-2000
25th anniversary, we employ the E282F tube in
triode mode as the second stage driver tube,
with a load of about 5K ohms, and using 20mA
of current. The listener can easily hear and
even "feel" the differences between this
design and other, more conventional, ones.
Please imagine, as you listen to the A-2000 25th
anniversary, its sound compared to the sound
of an amplifier with conventional 12AU7 or
12BH7's used as drivers, with a load of about
47K ohm, and using 2 to 3mA of current.
•“Full Engagement" Output Transformers.
Conventional output transformers use pre-set
secondary windings to accommodate 4, 8 and
16 ohm loudspeaker loads. However, these
conventional transformers utilize only one
secondary winding at a time, while the other
secondary windings remain "idle". This
approach has two adverse effects. First, the
output transformers are not working at their
maximum efficiency, reducing their output
relative to their potential. Second, the "idle"
windings are not actually "idle"; they are
subject to parasitic oscillations, producing
their own "signal". This undesirable electrical
information is additive to the transformer's
output, distorting the amplified signal going to
the loudspeaker. Allnic's "Full Engagement"
transformers address these issues by having 4
independent, secondary windings which are
always fully connected, never "idled". This
means that all secondary windings are always
connected to your loudspeakers, regardless of
which output switch position you use (4 ohms
or 8 ohms or 8 ohms or 16 ohms, depending
on the factory configuration you have
selected). The result is that there is neither a
loss of transformer output efficiency, nor the
introduction into the output signal of
distortion from parasitic oscillations of the
secondary windings.
•Large Nickel/FeSi Core Output Transformers.
As with our other models, Allnic uses very
large output transformers (96 mm) with nickel,

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mixed with FeSi, cores. This provides for higher
inductance with fewer windings than other
designs can provide and results in the great
benefit of an extremely wide range of output
frequencies.
•"Soft-start" Circuitry. Allnic uses soft start
circuitry that, after sufficient warm-up only,
provides the high voltage supply to the plate
of each tube. This protective design results in
prolonged tube life and fewer and less
frequent issues with tube performance.
•Analogue Power Tube Current Monitors. In
order to provide constant current (bias)
monitoring for the power tubes, Allnic uses a
separate analogue current meter for each tube.
The meters make it exceptionally easy to see
the status of each tube at any time and to
respond immediately to any variation in bias
by use of the bias control knob for the relevant
tube. The meters offer a simple, unambiguous
indication of each tube's status compared to
conventional LED bias monitors.
•"On-the-Fly" Triode/Pentode Switching.
Switching between triode and pentode
operation can be done "on-the-fly" at any time
while the amplifier is in use.
•Beautiful 10KHz square wave response. See
Figures 1-3.
Fig.1 Square Wave 50Hz Fig.2 Square Wave 1KHz
Fig.3 Square Wave 10KHz
Measured by LEADER LAG-126 Audio Signal Generator and
KENWOOD CS-4125 Oscilloscope.
•As are all Allnic Audio products, the A-2000 is
fully RoHS (EU Reduction of Hazardous
Substances regulation) compliant in
construction and materials.
WHAT’S IN THE BOX?
Please check that the shipping box contains the
following:
•One (1) Allnic A-2000 25th anniversary stereo
power amplifier
•One (1) Owner’s Manual
Note:
1) The A-2000 25th anniversary ships with the
tubes installed.
2) The A-2000 25th anniversary will work with
most IEC type
aftermarket power cords. Of course, only
you can determine the power cord that
works most synergistically with the A-2000
25th anniversary in your system.
3) Be sure the A-2000 25th anniversary is
labeled for the AC voltage of your location.
If it is not, please contact Allnic Audio.
We advise that you keep the box and other
packing materials that your A-2000 25th
anniversary came in. It will be useful if you sell
your A-2000 25th anniversary or in the unlikely
event you need to ship it for service.
SAFETY
•Remove ALL protective cushioning
material (cardboard around and “O” rings
on tubes) inside the tube chimneys before
operation. The tube chimneys should
contain NOTHING except the tubes.
•Disconnect the power cord by pulling the
plug, not the cable.
•Do not attempt any repairs. Do not remove
the unit’s chassis cover without specific
authorization from Allnic Audio.

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•Keep the power cord away from heat
sources
•Keep the unit away from liquids – do not
allow any liquid to enter the interior of the
unit.
•When the unit is moved from a cold to a
warm environment, allow sufficient time
for any condensation to evaporate before
plugging the A-2000 25th anniversary into
an AC connection.
•Do not attempt any repairs.
CLEANING
A. Chassis and glass
Use only a soft, lint-free cloth, dampened slightly
with water only (NO cleaning fluids!), to clean the
faceplate, chassis and tube chimneys of the A-2000
25th anniversary.
B. Connectors
You may use any good quality contact cleaner
recommended for such applications to clean the
contacts from time to time, as you deem
appropriate.
INITIAL SET-UP
A. LOCATION, LOCATION, LOCATION
Like all audio products using tubes, the Allnic Audio
A-2000 25th anniversary needs to be placed on a
solid stand in a location that provides good air
circulation around, above and below the A-2000
25th anniversary.
•DO NOT cover the top of the 2000 25th
anniversary.
•DO NOT place the unit on carpet or foam.
•DO NOT subject the unit to knocks and
shocks as you move it around. This advice
is meant particularly for those who may
want to place the A-2000 25th anniversary
on some kind of after-market isolation feet
or similar devices. Dropping one side of the
A-2000 25th anniversary, or the whole of
the unit, is not a good thing to do.
•DO NOT place the unit near a strong light
or heat source.
•DO NOT place anything heavy on the unit.
•DO NOT allow rubber or vinyl materials to
rest on the chassis for long periods of time.
This could discolour the metal.
•DO place the unit on a shelf or stand that is
stable and not subject to vibration or
sudden shock.
•DO consider using a high quality power
cord, interconnects and speaker cables.
The A-2000 25th anniversary is a highly
sensitive piece of electronic designed for
neutrality and will output what you put
into it.
•DO try to place A-2000 25th anniversary
away from major sources and potential
receivers of RFI and EMI. Though well
shielded, the A-2000 25th anniversary will
function best away from large power
transformers and other sources of such
interference and from other equipment
that could be susceptible to/sources of
such forms of interference.
B. INPUTS
There are two (2) pairs of female inputs. One pair
accepts balanced cables with male XLR connectors;
the other accepts cables with single-ended, RCA
type male connectors. These input connections are
located on the right (facing the chassis rear) rear of
the chassis, with the balanced inputs closest to the
side edge. In each case, the left channel
connections are above those for the right channel.
To the left of each XLR input there is a switch to
select one of two pin configurations for a balanced
cable (i.e., it changes the phase). The top position
is for pin 2” hot” and pin 3 “cold”; the bottom
position is for the reverse (in both cases, pin 1 is
ground).

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C. SPEAKER TERMINALS
The 2000 25th anniversary is equipped with high-
quality speaker terminals for each channel. These
terminals are located on the left side of the rear
panel of the A-2000 25th anniversary chassis (facing
the chassis rear), with the right speaker
connections closest to the left side of the chassis.
The terminals for the live connections, marked
positive “+” are on the top, and the return
connections labeled negative “-”, underneath.
Between the left and right pairs of terminals is a
switch that provides for either 8 or 4 ohm
impedance, as your speakers may require. The
upper position of the switch is for 8 ohm operation;
the lower for 4 ohm operation. 8 and 16 ohm
terminals are available by special order. The
terminals accept bare wire (not recommended) and
spade and banana type connectors. Please refer to
Figure 4.
D. POWER CONNECTION
Connect the input interconnect and speaker
cables before you insert the power cable into
the receptacle in the centre (facing the back)
rear of the chassis. The A-2000 25th anniversary
uses a standard three prong male IEC
connection for AC input. You need to use a
power cord with a female three prong IEC
connector at one end. Please refer to Figure 4.
The A-2000 25th anniversary you have purchased
is set internally for AC 220 volt – 60 HZ operation.
There is no way to change this to another AC
setting without return of the unit to the factory
for re-wiring, at the owner’s cost, including
transport both directions.
INITIAL POWER-ON
Once you have your A-2000 25th anniversary in
place and all connections have been made to your
source(s) and preamplifier, you are ready to turn
on the power for your A-2000 25th anniversary.
Before you power up the A-2000 25th anniversary,
though, be sure you have:
•removed ALL the cushion materials (cardboard
around and “O” rings on tubes) from inside the
tube chimneys
•selected the input connection that you want to
use, single ended (RCA) or balanced (XLR); and
if you are using the XLR connectors, set the
switch beside them to the appropriate pin
configuration.
•turned on your source(s) and your preamplifier,
and turned the preamplifier’s volume control
down to zero or otherwise muted its output
•securely and correctly fastened the speaker
cables and ensured that they are also
connected properly to the speakers
•checked that all power tubes are snug in their
sockets
Turn on the A-2000 25th anniversary by pushing in
the power switch button located at the right of the
front panel (facing the front of the unit) to the “on”
position (See Figure 5). The “on” position is with the
button switch depressed. Of course, the off
position is the reverse. After about a thirty to forty
(30 - 40) second delay (the soft start), the A-2000
25th anniversary will be powered on.
OPERATION
When the power is on, the current meters on the
top plate of the chassis will illuminate. From this
point on, operation is straight-forward. When you
are finished listening, turn off your A-2000 25th
anniversary first; then, turn off your preamplifier
and sources. If the A-2000 25th anniversary’s are in
triode mode at turn-off, they will produce a sound
through the speakers as the amplifier’s relays turn
off. Though this sound is harmless to speakers,
some users may prefer not to hear it. To avoid the
sound, simply switch the A-2000 25th anniversary’s
to pentode mode prior to turning them off (see the
“On-the-Fly Triode/Pentode Switching section
below).

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In the case of any failure, please contact Allnic
Audio for assistance.
“ON-THE-FLY” TRIODE/PENTODE SWITCHING
You can use the Triode/Pentode “Mode Selector”
button at any time during operation to switch back
and forth from Triode to Pentode operation. Press
the mode selector button down to have the A-2000
25th anniversary operate in Triode mode; press the
button again so it is in the raised position to have
the A-2000 25th anniversary operate in Pentode
mode.
THE CURRENT METERS
The two illuminated meters indicate the current
supplies to the four KT150 power tubes in the A-
2000 25th anniversary Between and to the outside
of each channel pair of KT-150’s is a small toggle
switch. Pushing the toggle toward the rear of the
chassis allows you to read and use the meter to bias
the rear KT150; pushing the toggle toward the front
switches the meter to the front KT-150. You can use
the toggle during operation.
There is a potentiometer for each KT150 . When
you turn on the A-2000 25th anniversary, the needle
of the current meter for each KT150 should be
between the two parallel lines on the meter face.
Any error of current supply to or failure of a KT150
tube is indicated by the needle on the meter
moving out from between these two parallel lines.
If a meter’s needle drops to the left limit of the
meter’s face during operation, this indicates a
failure of the related KT150 tube. You must turn off
the A-2000 25th anniversary and replace both the
fuse (0.5A, 250V, 20mm glass type) for that tube
and the KT150.
To replace a fuse, unplug the A-2000 25th
anniversary; then, using a screwdriver, simply turn
the top of the fuse cap counter clockwise. It will
spring out holding the fuse. Replace the fuse in the
fuse cap, push the fuse cap down and turn it so it
locks. If you have any questions about doing this,
please contact Allnic Audio for assistance.
TUBES AND TUBE BIAS
Each A-2000 25th anniversary uses the following
tubes:
•Four (4) x KT150
•Four (4) E282F
•Two (2) x 6AK6
Because of the individual bias for each KT150, it is
not necessary to use a matched quad of these
power tubes in the A-2000 25th anniversary.
If the needle of a current meter for a KT150 has
moved to the left of the parallel lines on the meter
face, using an appropriately bladed screwdriver,
adjust the potentiometer directly in front of that
tube’s location by turning it clockwise until the
needle has returned to between the meter’s
parallel lines. If the meter needle has moved to the
right of the parallel lines on the meter face, turn the
potentiometer control counter-clockwise to correct.
You may use any KT150 type tube in the A-2000
25th anniversary. Of course, you will have to adjust
the bias back into the area between the two
parallel lines of the meter for a tube when it is
replaced.
CAUTION: If you intend to change KT150’s,
ensure that you use the potentiometers to trim
back the bias below (to the left of) the parallel
lines on the meters first. This will prevent the
new pair of KT150’s from drawing too much
current at first turn-on (not an uncommon
characteristic) and tripping the power fuse at the
IEC connection. No harm is done to the original
tubes by turning the bias down, nor is any harm
done to the new tubes by having them biased low
to start. Once the new tubes are installed and the
A-2000 25th anniversary is on, use the
potentiometers to adjust the bias so the needles
for each meter are again between the two parallel
lines on the meter.

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SPECIFICATIONS FOR THE ALLNIC AUDIO A-2000
25TH KT150 STEREO POWER AMPLIFIER
Output Power:
100w x 2 (8Ω load,
at 1KHz)
Distortion:
0.2% at 1KHz at
10w
Frequency
Response:
20Hz - 20KHz Flat
•S/N Ratio: -80dB (CCIR, 1KHz)
•Damping Factor: 8 at 8Ω load at 1KHz
•Voltage gain: +24dB
•Input Impedance: 100KΩ (single-ended,
unbalanced)
•Input Sensitivity: 1.4V for rated power
•Tubes: KT150 X 4 (power triode)
E282F X 4 (second stage
drivers)
6AK6 X 2 (first stage driver)
•Fuses:
•Dimensions:
•Weight:
AC Mains - 3A / 250V (110W) (two supplied –
one is a spare). Tubes -
0.5A, 250V, 20mm glass type
(W x D x H) 430mm X 430mm X 240mm
40Kg (88.2 lbs) net.
55Kg (121 lbs) shipping weight.

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WARRANTY
All Allnic Audio amplifier products are warranted
against materials and manufacturing defects for
parts, excluding tubes, and labour for two (2) years
from date of purchase. Tubes are warranted against
materials and manufacturing defects for one (1)
year from date of purchase. The warranty is
transferable for the balance of the original
purchaser’s warranty period, provided, as stated
below, no unauthorized repairs or modifications
have been performed on the product. Date of
purchase is the date indicated on the invoice for the
product issued by Audiomentors.
For the warranty to be valid, a defective product
must be returned to Audiomentors for service prior
to any unauthorized attempt to repair. Any repair
work on an Allnic Audio product not specifically
authorized by Audiomentors will void the warranty
on the product.