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Quick Set Up Guide - icon Audio Stereo 25 MK II Quick Start Manual

Ultralinear push pull amplifier el34 or kt88

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IMPORTANT READ THESE NOTES THROUGH FIRST!
1 Unpack unit carefully. Make sure that it is in
good condition. If not report to your reseller. It is
important
that
you
warranty/service return.
2 If necessary fit the valves, or check that they
are firmly in place. The bigger output valves
(EL34/KT88) should be fitted first observing the
numbers 1,2,3,4 on the rear of the valve; this
corresponds with the four REAR sockets from left
to right viewed from the front. This was the
position the valves were tested in. Do not push
or pull these valves unduly by the glass
envelope, this could cause the glass envelope to
become detached from the base. Be careful to
note the correct orientation of the central
"keyway" between the pins otherwise damage
could occur. (Damaged valves are not covered
under warranty)
The smaller valves are normally numbered 5,6,7
again left to right (see page 1 photo) and should
be gently pushed into place. The middle valve is
6SL7 and the outside pair are 6SN7/CV181 Some
Russian tubes may have different numbers, if so
go by the number written on the valve.
3 Connect to source units, e.g. CD, Tuner,
Phono pre amp, MP3, AV etc via appropriate
phono sockets. No "recording" or line output
facilities are provided. For this you could use our
"Passive" or "Passive R" remote control pre amp.
Or refer to Bluetooth section.
4 Connect to speakers Make sure to get the
correct polarity of speaker cables. (See speaker
connections chapter). If 'bi-wiring' both 'common'
should go to the black terminal, and both 'positive'
(or red) should go to the red terminals. Most
speakers have a "spread" of impedance between
about 3 and 14 ohms. As there is some "overlap"
between the 4 and 8 ohm outputs, you may wish
to try both to experiment which tonal balance you
prefer.
5 Connect to mains supply using supplied IEC
mains lead to 230/240V supply (or 117V if
modified see label). If for some reason the
welded plug must be removed, please remove
fuse and dispose of immediately. (As they can
be dangerous to children). The replacement plug
should be wired Brown to Live terminal, Blue to
Neutral terminal and Green/Yellow to Earth
terminal.
6 SWITCH ON! The LED mains indicator should
light up. After about 40 seconds the amplifier
should start working. All valves should have a
visible orange glow from the cathode heaters.
With the volume control set to minimum (fully anti-

2 QUICK SET UP GUIDE

keep
packaging
for
clockwise) there should be no sound coming from
the speakers except a barely discernible hum. If
there are any unpleasant sounds coming from the
speakers, switch off and refer to the 'Trouble
Shooting' section or contact your reseller or Icon
Audio.
7 Your unit should now be functioning. If not
check
wiring
again
monitor/volume to choose source program and
suitable listening volume. Do not operate at a high
volume for the first few minutes to allow the valves
to warm up properly.
Please note 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 have a "new" smell for a few
weeks.
D, Mobile phone 'breakthrough' is normal.
E, Valves may make a 'tinkling' sound when
warming up and cooling down.
F, One channel may come on before the other at
switch on.
G, There may be a 'click' when switching off.
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
circumstances. Always unplug when making
adjustments. Like all amplifiers there are
potentially hazardous voltages inside, which
when switched off can take about 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 bias pre set without reference to the
manual. Incorrect adjustment could cause the
valves to overheat, resulting
valves and amplifier.
To maintain the best performance of the
amplifier you should check the bias of the
output valves from time to time (say once a
year). Full details will be found in section 6.
In this manual we have attempted to give you all
the information to enable you to get the best out of
this amplifier, without being overly long or too
technical. However, we are always keen for
feedback
on
errors
information within!
and/Use
selector/tape
in
these
in damage to
or
omissions
on
the
Page 3

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