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grid bias pre sets without reference to the manual.
Incorrect adjustment could cause the valves to
overheat, with resulting in damage to valves and
amplifier.
12. Important that you check the check the
bias reading once or twice a year. This will
ensure peak performance and maintain valve
life. See section 8.
Remote Control
The remote control can be found in the bottom of
the box. You may need to pull the plastic tag out
to connect the batteries and tighten the screws. It
controls the volume by means of an ALPS
motorised volume pot.
Pressing “mute” will reduce
the volume to zero. Make sure that you point the
control directly at the sensor on the amplifier front
panel. If you are having difficulty operating the
handset from an oblique angle, try pointing at
something reflective, e.g. the opposite wall, or
place a small reflective item at a suitable angle in
front of the amplifier. A small dot of white paint or
“Tippex” will enable the little “dimple” on the
volume control to be more visible if required.
Pleas
e note that upon “switch-on” the remote
control unit automatically re-sets to a low volume.
When the LED gets dim you should replace the
batteries with 2 x
“alkaline” AAA cells.
When not in use or in storage remove the
batteries to prevent leakage and corrosion.
4 Connecting inputs & outputs
Many problems associated with audio involve bad
contacts with connecting cables and plugs.
So it’s
worth making sure that you have good
connections and that your leads are the right way
round.
Inputs
The amplifier will work with any standard piece of
hi fi e.g. CD, Tuner, Tape Deck, Mini Disc, TV,
Video Recorder, DVD etc having an output of
300mv or more, to get full power.
If you wish to use a turntable you will need a
suitable phono pre-amp. Icon Audio or your dealer
can advise you. Our PS1, PS2 or PS3 pure valve
phono stages make ideal partners.
To use the integrated version as a power
amplifier. See section 5.
Connecting a tape deck
The STEREO 60 MK IV will work with any tape
deck having suitable output and it is possible to
record from any connected source using the
terminals marked ‘Rec Out’. The STEREO 60 MK
IV
has a ‘Tape Monitor’ facility, which enables you
to use a ‘three head deck’ or an equalizer.
Some tape decks ‘Present a load’ to the amplifier
terminals, even when not in use, which can affect
sound quality. (You can do an audible check for
this by removing the plugs and listening for a
change). Therefore for best results do not leave
anything
connected
to
these
terminals
unnecessarily.
Connecting loudspeakers 4or 8 Ohms?
The output impedance of the Stereo 60 MK IV has
been optimised to work with 3-12 ohm speakers.
Many modern speakers use a 4 ohm bass unit
and an 8 ohm tweeter, as this then falls between
the two impedances either 4 or 8 Ohms will be
suitable with the 4 ohm having a slightly heavier
sound. Bear in mind that there is quite a lot of
“spread” with the 4 and 8 Ohm taps, so they
overlap some. If Bi Wiring it is permissible to
connect the tweeter cable to 8 ohms and the bass
unit to 4 ohms, or vice versa
Use good quality loudspeaker cable. This should
be relatively thick and multi-strand
ed. i.e. QED ’79
strand
’ or better. Take care to connect the correct
polarity. The use of ‘Banana plugs’ or ‘spade’
connections will ensure a good connection whilst
minimising the risk of ‘shorts’.
Speaker cables
In our experience valve amplifiers are more
tolerant of cables; therefore some of the benefits
of
very ‘exotic’ cables may be lost! But this is
personal taste. Icon or your dealer will advise you.
As all cables have losses, keep the speaker
cables short, although anything under 5m will
have little effect.
You can
either ‘hard wire’ your cable to the
amplifier by baring enough cable to fit in the
connector and twist together to avoid any spare
strands touching anywhere else (soldering the
stands together helps).
Be warned this amplifier
does not have an output protection device,
which would degrade the sound. So a
prolonged short due to strands of wire
touching could cause damage!
Alternatively use
good quality ‘banana’ plugs, once fitted they are
trouble free.
Speaker polarity.
It is essential that you observe the polarity of the
terminals; they must be the same for the left/right
connections at the amplifier end and at the
loudspeaker end. Otherwise
the sound will be ‘out
of phase’ with the sound stage ‘inside out’ with
reduced bass.
If you are unable to check this or
confirm the polarity
(e.g. if you have ‘built in’
wiring), try the following; Connect the system up
and play some music with plenty of bass (e.g.
dance music), preferably in mono (FM tuners are
usually switchable to mono) and stand the
speakers close together. If correct you should
hear plenty of bass, if not
reverse the terminals
for one channel only, either at the amp or
speaker.
You will now hear more, or less bass.
The higher bass output is the correct setting to
use. An easy alternative is to use a test disc.
The STEREO 60 MK IV is designed to work with
wide range, low to medium efficiency having
impedance of 4 ohms to 8 ohms. Speakers having
efficiency of lower than 80db may have greater
difficulty in providing a high sound level. But this