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Many problems associated with Hi Fi equipment involves
connecting leads, which are usually either 'BAD
CONNECTION' or a 'WRONG CONNECTION'. So it's
worth making sure that you have good connections and
that your leads are the right way round.
Also there are too many possible combinations of
circumstances to list all possible fault combinations here.
Common problems are listed below:
1. Amplifier Dead
Check the 1.6 amp (3 amp USA) mains fuse at the
back of the amplifier. To gain access, remove the
mains lead. The fuse is in a small plastic drawer,
which forms part of the socket assembly. To open
insert a flat bade screwdriver or similar and prise
open. The fuse in use is the innermost the outer is
a spare. Should the replacement fuse also blow there
is a fault. Replacements should be 1.6 (or 3 amp
USA) amp 'anti-surge'. Available from Icon Audio free.
The fuse in the plug should be a 3 or 5 amp fuse,
although unlikely, this should be checked if the
amplifier fuse is OK, or another mains cable tried.
2. No sound
The ST40 is lit up but no sound from one channel.
And the bias reading is "zero" on that channel. This
could be one of the 250mA HT fuses which are
located inside the amplifier (its highly unlikely that
both will fail). Ideally an engineer would replace these
but if this is not possible DISCONNECT THE POWER
CABLE, invert the amplifier, remove bottom plate and
replace the fuse on the problem channel two spare
fuses are attached to the bottom plate. Also look for
burnt resistors on the 6L6s base as this could be due
to valve failure in which case the resistor which
protects the amplifier from damage will also need
replacing.
(Replacement fuses are available free from Icon
Audio in the UK).
If all four of the output valves have a bias reading
check:
Have you selected the right input?
Are the connections OK?
Is everything switched on?
Are the speakers connected?
One of the 6SN7/CV181/6N8 valves may have failed.
This may be proved by swapping from the working
channel.
If the problem persists the amplifier may need to be
serviced. Contact your dealer or Icon Audio.
Distorted sound.
Try another source; if sound improves then it's probably
something wrong with the first source. If no improvement
try different speakers, if no improvement could be an
amplifier problem.
Hum Problems
If you experience hum, try disconnecting all inputs, if
hum persists this is probably an amplifier fault.
If not, identify which input is causing hum. Connect one
input at a time. A common cause is a 'hum loop' caused
by having too many earths, and may be identified by
unplugging each input source from the mains. One
remedy for this is to use an interconnect which only has
the screen connected at one end. Other causes of low-
level hum can be from adjacent equipment, so
5 Trouble Shooting
experiment with moving equipment around to see if
this makes the hum better or worse.
Interference Problems
The amplifier design incorporates features and
devices which make it resistant to mains-born
interference. But some heaters, boilers, fridges,
cookers etc can generate intermittent RF (radio
frequency) interference which travels through the air
(and walls). Although rare this can be very irritating.
In this case a simple capacitor is often all that is
needed to effect a permanent cure (contact us).
One channel missing.
Usually 'bad' connection on either the input or the
speakers. Try swapping the connection over to
establish if the cause is:
(a) Input to the amp.
channel.
(b) Amplifier or speakers.
(c) If none of these, check internal fuse for that
channel (see section 5.2).
Strange noises coming from speakers:
Turn volume to minimum on unused input, if the
problem is corrected either fault with source unit or
with connection. If noise persists, problem with
amplifier.
Valve overheating
If the whole output valve glows red (other than the
heater), often accompanied by a hum through the
speakers, switch off immediately, and refer to Icon
Audio or a service engineer, as this could be valve
failure.
A valve that is lit up is not a guarantee that it is
working properly; conversely a valve that is not lit up
will not be working (usually cold to the touch).
Valve Replacement (see also section 6)
Valve life will depend upon such things as hours of
use and number of on/off cycles, Do not switch on
and off unnecessarily. Also it is not good practice to
remove the valves unnecessarily as this can strain
the pins and cause tiny air leaks.
Service: Should you suspect a problem, you could
return the unit to Icon Audio for a periodic service or
return the valves for testing free of charge. You
should carefully remove the valves (the 6L6/KT66
should be held by the base when removing)
numbering them with a marker from left to right as
you do so in order that that may be replaced in the
same position. They should be well packed in
cardboard & foam or similar, and returned to Icon
Audio for testing. (Valves are very rugged if packed
properly).
Mains Supply
This amplifier is configured to work on 230/240v ac,
(or 117v USA, Canada) this may be changed over.
Contact us for more information.
Sound will move to the other
Sound will not move.
Page 6
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