4
Trouble shooting
Hum Problems
The very low output of a pickup cartridge means that
it can be prone to hum problems. Although you may
hear more noise at a very high listening level, a loud
volume should be possible before this becomes a
problem. In some situations,
“too many earths” may
induce hum, in which case try the switch on the rear
of the unit as this may solve the problem.
Most turntable/arm combinations have a separate
“grounding” lead for the arm. Make sure this is
connected to the rear of the PS1. You should also
keep amplifiers and other equipment away from the
pick up arm (including above and below) and cables.
Amplifier Dead
If the LED or valves do not light up, first check the
wall plug fuse (there may not be one outside the UK)
there is also a 160mA (250mA USA) mains fuse
inside the IEC socket on the rear of the amplifier
(with a spare). This should only be replaced by a
qualified
electrician!
(NOTE
for
electrician:
disconnect from supply, allow 30 mins to discharge
HT circuit, the fuse cover with a small flat blade
screwdriver replace the front fuse with the spare at
the rear, replace cover and re-insert mains lead and
test Replacements should be 160mA (250mA USA)
‘time-lag’. Refer to Icon Audio for further information.
The fuse in the UK mains plug should be a 3 amp
fuse, although unlikely, this should be checked if the
amplifier fuse is OK.
No sound
Have you selected the right input? Are the
connections OK? Is everything switched on? Are the
speakers connected?
Valve Replacement
Valve life will depend upon such things as hours of
use and number of on/off cycles. A valve may be
considered to have come to the end of its life when
the sound quality has changed or it has become
noisy and microphonic. Ideally you should replace all
three at the same time. As a rough guide we would
expect about 3000 to 5000 hours per set.
If the unit is working OK it is best left alone. The most
common faults are low level hiss and spitting noises,
and becoming excessively microphonic.
If one channel is causing concern basic fault finding
may be done by swapping the two right hand valves.
All three valves are the same type but the single left
hand valve does a different job, so this may also be
inter-changed with the other two, and may give
improvement as this position has a less critical task.
As the valves are crucial to maintaining the
performance and quality, choose them with care.
In order to gain access to the valves you will need a
2.5mm
“Allen Key” to remove the valve screening
rings. The valves may then be gently pulled out with
a slight
“rocking” motion. YOU MUST DISCONNECT
THE POWER SUPPLY 20 mins BEFOREHAND.
Warning:
It is worth noting that this pre amplifier will
benefit from the best ECC83 valves. These are
unlikely to be “tested, off the shelf”, NOS or Second
Hand valves, but valves which have been tested and
matched in a PS2 to check that they are not noisy or
microphonic in the PS2. In the process of testing and
commissioning we reject about 15% of valves for this
reason. Used valves are unlikely to work well. We
have also found some
“premium” valves to have no
advantage. At the time of writing the EH, Tung Sol,
Genelex,
SG
have
been
consistently
good
performers. But feel free to experiment!
Icon Audio are happy to replace valves and check
the performance of your amplifier, there are often
upgrades available such as the excellent Mundorf
capacitors which have a rich expansive warm
sound.
A replacement set of valves from Icon Audio will
be tested in a PS2 before despatch to ensure
ideal sonic performance.
It is essential that only the correct valves are
used as similar looking valves have a different
pin connection and insertion could result in
damage to the amplifier and risk of electric
shock. If in any doubt consult your dealer or Icon.
Service:
Should you suspect a problem, you should
return the unit to your dealer or Icon Audio for a
periodic service or return the valves for testing free of
charge.
Specifications and Features
•
All hand wired point to point
•
No printed circuit board to ‘colour’ sound
•
All Triode valves
•
3 x ECC83/12AX7
•
Sensitivity: 5mv for 1.6v
•
Gain = 320 MM = 50dB
•
Load: imp: 47k MM
•
Signal to noise level -75db (MM unweighted)
•
RIAA Freq response 20hz-20khz +0 - 1db
•
No overall feedback used
•
Mono switch for mono records
•
High quality close tolerance resistors
•
LED mains indicator
•
Polypropylene audio capacitors (upgradeable)
•
Silver PTFE audio cable
•
DC supply for valve heaters
•
Black Matt or Stainless steel chassis
•
6mm solid alloy side plates
•
Gold plated Input terminals
•
220/240 volts 30watts 160mA (250mA USA) time
lag fuse
•
UK Plug fuse 2A
•
C E certified
•
275mmW, 250mmD, 115mmH , 2.47kg
(Figures in brackets allow for rear connections)
(Specifications subject to change, errors & omissions excepted 19/02/20)
Designed and developed by David Shaw and Barrie
Roberts in Leicester, each pre-amp is carefully
checked & tweaked plus any custom modifications
added as required before undergoing rigorous tests
in all its important static & dynamic parameters.
Finally each pre-amp is run to allow the valves to
“bed in” for 24hrs to ensure you get the best
performance.
icon Audio
(UK) LTD
351 Aylestone Road Leicester LE2 8TA UK
www.iconaudio.co.uk Email: [email protected]
Phone +44(0) 116 244 0593 44 (0) 778 715 8791
Direct 19/02/2020