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it is not in use. It is using electricity and valves
have a finite life. (About 9 months continuous
use).
'Burning in'
Although the amplifier should sound good within
about 10 mins it can take up to an hour to sound
at its best and will take several months of regular
use before it is fully 'run in'.
Upgrading Valves!
Quality valves should sound better and have a
better service. The valves supplied with selected
models are the result of careful comparison with
other makes. But beware of paying a premium for
Amplifier Dead
Check the 5 amp 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 blade 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 you should disconnect
from the mains and seek qualified help or Icon Audio.
Replacements should be 5 Amp 'anti-surge'.
The fuse in the wall plug should be a 5 amp fuse,
although unlikely to fail, this should be checked if the
amplifier fuse is OK.
There is also a HT fuse inside the amplifier. This
would not normally blow unless there is a valve fault
or an overload condition. Ideally this should be
checked by a competent engineer. Disconnect
amplifier from the mains power and wait 20 minutes
before removing bottom plate. If the HT fuse has
blown, there are replacements inside. Replace
bottom cover afterwards and check bias immediately
after switching on. Should the fuse blow again the
amplifier will need a service.
No sound
Have you selected the right input? Is the "Tape Monitor"
switch up? Are all the connections OK? Is everything
switched on? Are the speakers connected?
Distorted sound.
Could be your source, the speakers or the amplifier,
check all wiring, and try swapping things around to
eliminate or prove which component is the problem.
Left or right amplifier? If both probably the source unit.
Try another source. If one amplifier is distorted check the
bias. No bias reading means either a fuse blown or a
faulty valve. This could be due a faulty 805 or one of the
805 internal fuses blowing. A symptom of this would be
no bias voltage at the test point. Also the valve would not
be as hot as normal. Refer to an engineer or to Icon
Audio. Spare internal fuses are secured inside the
chassis. Replacements are available free of charge from
Icon Audio.
If the amplifier lights up and there is no sound/distorted
sound this could be due to failure of one of the small
valves, see also section 7.
Hum Problems
If you notice a gradual increase in hum over a period of
time, the hum balance of the 805 may have drifted out of
"balance" Using a long flat blade screw driver carefully
adjust for minimum hum, if your speaker is far away the
*See engineers notes at rear
"New Old Stock" valves where you may be paying
for rarity value and not performance. Icon Audio
normally keep a range of upgrade valves in stock.
Cabinet Care
To remove dust we suggest gentle brushing of the
polished stainless steel cabinet with a soft
paintbrush. Other marks can usually be removed
with a damp cloth. The Perspex valve cover may
need a gentle wipe with soapy water and drying
with a duster. Never use anything wet on the
amplifier, and always clean with the power
disconnected.
5 Trouble Shooting
use of a second person with their ear to the speaker
may be helpful. If the above does not work and you
have tried the advice in the next paragraph, you may
have a fault.
If not the above and the hum is at a relatively high
level, especially when you are installing or making
changes to your system: 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 experiment with moving equipment
around to see if this makes the hum better or worse.
Strange noises coming from speakers
Turn volume to minimum on unused input, if the
noise disappears, the fault is with the source or the
connection. If noise persists, the problem is with
amplifier.
If the whole 805 output valve glows red (other than
the heater), often accompanied by a noticeable hum
through the speakers, switch off immediately, and
refer to Icon Audio or a service engineer, as this
could be valve failure.
Service: Should you suspect a problem, you could
return the unit to your dealer or Icon Audio for a
periodic service or return the valves for testing free of
charge. You should carefully remove the valves (the
805s should be held by the base when removing, to
prevent damage) 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 hard wired to work on 230/240v ac.
The transformer may be re-configured for 117v ac by
a qualified engineer. Contact for more information.
This manual is provided for guidance only, and is not
intended as a comprehensive service manual. In
case of problems you should refer to your dealer or
directly to Icon Audio.
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