Page 4
2 QUICK SET UP GUIDE
1 Unpack unit carefully
. Make sure that it is in good
condition. If not report to Icon Audio. It is important
that you keep packaging for warranty/service return.
2 Check that the valves are fitted properly.
This
can be done by sight as they are unlikely to have
moved in transit. Always try and handle by the base,
with 300Bs be careful when removing, use a soft
cloth.
3 Connect to source or pre-amp.
The left & right amplifiers may be identified by the
colour of the input phono socket.
4 Connect to mains
supply using supplied IEC mains
lead to 240v supply.
If removing the welded plug,
remove fuse and dispose of safely
(As they can be
dangerous). The replacement plug should be wired:
Brown to Live terminal, Blue to Neutral terminal and
Green/Yellow to Earth terminal.
6 SWITCH ON!
The blue mains indicator should light
up and unit will take approximately 40 seconds to start
working. All valves should have a visible orange glow
from the cathode heaters. With the minimum volume
there should only be a barely discernable hum from
the speakers.
If you experience a switch on ‘thump’ through your
speakers on starting your pre-amp, try switching on
your pre-amp before the MB25s.
7 The MB25s should now be functioning
. If not
check wiring again and/Use selector/tape
monitor/volume to choose source program and
suitable listening volume.
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
recommend in these circumstances. Always unplug
when making adjustments.
Like all amplifiers there
are potentially lethal high voltages inside (500v
DC), which when switched off can take up to 15
mins 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.
3 Connecting inputs & outputs
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.
Inputs
The amplifiers will work with any standard hi fi source
e.g. pre-amp or CD capable of 1.9v output. The
position of the volume control will vary with the input
voltage of different units, this has no effect upon
performance.
4 Things you must know
The MB25 is a simple design fixed bias
amplifier, it does not have complex
protection circuitry for reasons of sonic
purity.
•
Never switch off and on quickly, this could
cause damage. Allow at least 60 secs.
•
Do not adjust the ‘bias’ settings without
reference to the instructions, this could be
dangerous and cause overheating.
•
Never operate without the speakers.
•
If you notice any abnormal behaviour, eg
overheating or hum etc, switch off and consult
your dealer or Icon Audio.
•
Only use 6SL7 & 6SN7 driver valves. Other
types have different pin connections which
could result in high voltage being fed back to
the input source and risk of shock.
•
A switch-off ‘click’ through the speakers is
normal.
•
Mains transformers may hum or buzz.
•
Mobile phone ‘breakthrough’ is normal
•
Storage in damp conditions could damage
transformers, keep the amps dry when not
in use.
Connecting Leads
Use good quality connecting leads, which are no
longer than they need to be. However good quality
leads are not expensive, and once that level is
reached further expense will not result in
improvement.
Like other units of hi fi hum may picked up from the
transformers of other units. This may require careful
siting to minimise this. See also ‘hum problems’.
Leaving the amp switched on
People sometimes ask if the amp should be left
running 24/7. Whilst the amplifier will sound at its
best when it is properly warmed up, there is no
advantage leaving it switched on when not in use. It
is using electricity and valves have a finite life. 300b’s
are directly heated and warm up very quickly.
Conversely the valves and other components are
stressed more at switch on; therefore do not switch
on and off unnecessarily.
Although the amplifier
should sound good within about 10 mins, like
most hi fi units it can take up to an hour to sound
at its best and will take up 200 hours before it is
fully ‘run in’.
Cabinet Care
To remove dust from the cabinet and valves we
suggest gentle brushing with a soft paintbrush and a
duster. Finger marks can usually be removed with a
damp cloth. The Perspex valve cover may need an
occasional gentle wipe with a damp cloth drying with
a duster. On no account use anything wet on the
amplifier, and always clean with the power
disconnected.
Содержание MB 25
Страница 3: ...Page 3...
