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IMPORTANT READ THESE NOTES BEFORE CONNECTING TO AC MAINS!
2 QUICK SET UP GUIDE
1 Unpack unit carefully
. Make sure that it is in good
condition. If not report to Icon Audio. It is important
that you keep the packaging for warranty/service
return.
The contents of the 3 box’s are 2x MB150, 2x
cover, 2x Mains cable,
1x manual, 4x 6SN7, 8x KT120.
The “Left” and
“Right” amplifiers may be identified by the serial
numbers or the Red and Black bands on the RCA
phono sockets at the rear of each amplifier.
2 If Necessary fit the valves, or check that they
are firmly in place as shown on
PREVIOUS PAGE
INSERTION DIAGRAM.
Fit the valves according to the numbers written
on the base, normally 1-12.
The KT120s should be
fitted first to the four
REAR
sockets (the two sockets
nearest the transformers). To avoid damage to the
valves hold the valves as close to the base as
possible
NOTE THE “LEFT” and “RIGHT” KT120
orientation on each amplifier. Also keep the left
and right amplifier valves separate.
Be careful to align the
central “spigot” of all
valves before insertion. They can be easily
broken and is not covered by the warranty!
The smaller valves should be gently pushed into
place. The 6SN7s (CV181) are fitted to the right hand
base (the same side as the triode switch) and the
6SN7 to the left hand base (the same side as the
standby switch).
NOTE: The KT120s and 6SN7s are NOT
interchangeable! This will result in damage and
could be dangerous!
3 Connect to source unit
, e.g. pre-amp or source
with adjustable volume control. Via appropriate
phono sockets.
4 Connect speaker terminals
use “0” &“8 ohm”
terminals unless you have 4 ohm speakers (see P5)
Make sure that the polarity is correct. (See speaker
connections chapter 3
). If ‘bi-wiring’ both ‘common’
should go to the black terminal, and both ‘positive’ (or
red) should go to the red terminals.
5 Before connecting to AC power, Check that the
power switch on the front is “off”. The “standby”
switch should
be in the “up” position and select
“ultralinear”.
Then connect the supplied IEC mains
lead to a 220-240v supply (or 115v).
If for some
reason the UK welded plug must be removed,
please remove plug fuse and dispose of
immediately.
(As they can be a danger to children if
plugged in). The replacement plug should be wired in
the following way Brown to Live terminal, Blue to
Neutral terminal and Green/Yellow to Earth terminal.
6 Before switching on make sure that the
“standby switch” is in the “up” position.
SWITCH ON!
The blue mains indicator should light
up. Leave for at least 2 mins for the valves to warm
up, and then
push the “standby” switch into the
“down” position. You will hear a “whumm” sound. The
amplifier should now be working. All valves should
have a visible orange glow from the cathode heaters.
With the pre amp volume control set to minimum (or
nothing connected) there should be no sound
coming from the speakers except a barely
discernable hum. If there are any unpleasant
sounds coming from the speakers, switch off and
refer to the ‘Trouble Shooting’ section or contact
Icon Audio.
If your unit is fitted with the optional HT delay timer,
operation will begin after the unit switches the HT
on (approx 1 to 2 mins). You may hear very low
distorted sound from the speakers during the warm
up time. This is because there is virtually no HT to
operate the amplifier. You should reduce the
volume until the HT cuts in.
6a Sensitivity switch on the rear.
Located on the rear this switch is normally set to
down
“L” (Low sensitivity) for pre-amplifier use.
For high sensitivity (passive) operation
use “H”. But
this is a matter of personal preference, as you may
find that you have enough gain and power in the
“L” position.
7 Your unit should now be functioning
. If not
check wiring again. Do not operate at a high
volume for the first five minutes to allow the valves
to warm up properly.
All these things are normal for valve amplifiers
A, Valves can get very hot, BEWARE!
B, The transformer cover will get quite warm
C, The amplifier may smell a little when new.
D, M
obile phone ‘breakthrough’ is normal.
E, Valves may make a ‘tinkling’ sound when
warming up and cooling down.
F, One channel may start before the other.
G, There may be a mechanical noise when
switching on.
H, T
he occasional “click” or “pop” is normal.
8 Health and Safety
. The valves when operating
have high surface temperatures. Keep out of reach
of children and pets. The use of the supplied guard
is recommended in these circumstances. Always
unplug from power when making adjustments.
Like
all amplifiers there are potentially lethal high
voltages inside, which when switched off can
take twenty minutes to discharge!
Do not
remove bottom panel unless you are a competent
engineer. There are no user serviceable parts
inside.
Like
other
household
electrical
appliances do not leave unattended whilst
switched on.
Do not adjust the KT120 bias pre
sets without reference to the manual. Incorrect
adjustment could cause the valves to overheat,
with resulting
in damage to valves and
amplifier.
Bias Adjustment:
The bias adjustment is factory set. No initial
adjustment is necessary.
To maintain the best performance of the
amplifier
you or an engineer must check the
bias of the output valves twice a year. Or if you
suspect a problem.
Full details will be found in
section 6.
