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source from the mains whilst still connected to the
HP8, the hum may then disappear. One remedy for
this is to use an interconnect which only has the
screen connected at one end. Some expensive
interconnects are not screened so try with a standard
alternative. 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.
The test for excessive hum coming from the HP8 is to
check it with nothing connected at "zero" volume. If the
hum is barely discernible this is normal. You will notice
some hum on one channel if the volume is turned up,
this is normal, but it will disappear when connected to
a source component. Contact us for further advice.
One channel missing.
Usually 'bad' connection on either the input or the
headphones. Try swapping the connection over to
establish if the cause is:
(a) Input to the amp.
channel.
(b) Amplifier or headphones. Sound will not move.
Strange noises coming from headphones
Turn volume to minimum on unused input, if problem
corrected either fault with source unit or with
connection. If noise persists, problem with amplifier.
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.
Valve Replacement
Valve life will depend upon such things as hours of use
and number of on/off cycles, as all the valves are
lightly loaded. As a rough guide we would estimate life
of approx 4 to 10 years. But this can vary.
What can happen?
A valve is at the end of its life if one of the following
happens:
The valves wear out reducing the sound
quality (after 2-5 years depends on use).
Any of the six glowing heaters fails in any one
of the 6SN7s or the ECC83
A valve could get "noisy" or excessively
"microphonic"
microphonic).
The emission (and therefore output and sound
quality) may fall giving low output.
The valve works intermittently.
An air leak causes the valve to fail and the
silver "getter" material to turns white.
To maintain the sound quality we recommend the
valves be changed every 2-5 years to maintain the
full sound quality. A new set of valves will give you
back a "NEW" HP8!
Icon Audio can supply a new set of valves which
are ideal for the HP8 ranging from standard to
"premium" types. The will be matched and tested
for quality, and audio tested again to check that
they are sonically perfect. Don't skimp on valves!
It is essential that only the correct valves are used
as some similar looking valves have a different pin
connection and insertion could result in
damage to the amplifier and risk of electric shock.
It is not good practice to remove the valves
unnecessarily as this can strain the pins and cause
Sound will move to the other
(all
valves
are
a
micro air leaks. Icon Audio are happy to check valves
and check to performance of your amplifier, and advise
on the latest upgrades available FOC.
Method:
Switch off, disconnect from mains and allow to stand
for 20 mins to allow voltages to discharge. You should
carefully remove the valves, these should be held by
the base when removing to prevent damage. Care
should be taken when removing and inserting the
6SN7's not to break the centre spigot. (These valves
also have an alignment "key" and will only fit in the
valve base one way and do not use excessive force;
accidental wrong insertion would cause damage). The
ECC83 does not have a centre spigot but note the
space in the valve pin layout and align this with the
area with no holes in the valve base. Do not operate
without valves!
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 they
should be well packed in cardboard & foam or similar,
and returned to Icon Audio. (Valves are very rugged if
packed properly).
We welcome any comments you may have regarding
errors or omissions in this manual.
Should you need further advice or information
regarding the use of this unit please contact us.
NEW OWNER?
If you have bought this unit from someone else, please
register with us by email or post stating your name,
address, model, serial number and whom you
purchased from in order that we can keep you up to
date with upgrades and improvements
All hand wired point to point
No printed circuit board to 'colour' sound
Japanese Blue ALPS volume pot.
Class A, all Triode circuit
Output impedance matching from 16 to 600Ω
2 x 6SN7/CV181 output valves
1x ECC83/12AX7 first stage valve (ECC81/12AT7 compatible)
2x 800mw output per channel max (depending upon load)
little
Signal to noise level -90db
Freq response better than 20hz-20kHz
Total harmonic distortion typically less than 0.2% 1khz
Japanese steel EI transformers with low oxygen copper
High quality 2W metal film, & wire-wound resistors
LED mains indicator
Polypropylene audio capacitors or Jensen upgrade
Silver PTFE audio cable
Custom hand wound output transformers
Gold plated Input terminals
One line input with "loop out" facility
300mv input sensitivity for full output
230/117volts 30 watts.1.0 A (2A USA) anti-surge fuse.
C E, ROHS and WEEE compliant where applicable.
16cm W, 28 cm D, 16.5 H, 6 kg (allow space for connections)
(Specifications subject to change, errors & omissions excepted. General 16/02/17)
icon Audio
Ph +44 (0) 116 244 0593 +44 (0) 7787 158791
Specifications and Features
(UK) Ltd
351 Aylestone Road
Leicester LE2 8TA
www.iconaudio.com
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