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3 Connecting inputs & outputs
Most problems associated with electronic equipment
involve 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 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 250mv or
more, to get full power.
If you wish to use a turntable you will need a phono
pre-amp. Icon Audio make several pure valve models
ideal for the ST30se. See our website or your dealer
can advise you.
“H” & “L” sensitivity/Power Amplifier mode.
Located on the rear of the amplifier the High and Low
sensitivity switch has two functions.
“H” gives higher
sensitivity with lower “feedback”. “L” gives lower gain
with higher feedback. Either setting may be used
depending upon personal preferences. We suggest
trying the “High” setting initially, this will give you
good volume levels even with low output devices
such as an iPhone the low feedback is suited to older
speaker designs.
The “Low” setting may be used if you find you find
the volume control is “too steep”, or if you want to
use a line pre-amplifier. Also the higher feedback
may better suit more modern design of speakers.
Switching may be done during operation The tape
input will provide the most direct signal path.
Feedback.
The sensitivity switch does not attenuate
the signal, but alters the gain by adjusting the
feedback within the ampl
ifier. In “H” the feedback is
low, in “L” position the moderate.
Connecting a tape deck/Recorder/Equaliser
The STEREO 30se will work with any tape deck
having suitable output, and it is possible to record
from any connected source using the terminals
marked ‘Pre-out’. The STEREO 30se 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 “Rec out” unnecessarily.
Connecting loudspeakers
It is important to use good quality loudspeaker cable.
This should be relatively thick and multi-stranded. i.e.
QED ‘Original’ 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’.
In our experience valve amplifiers are more tolerant
of cables, therefore the benefits of very ‘exotic’
cables may be wasted! But this is personal taste.
Icon or your dealer will advise you.
As all cables have losses, keeping the speaker
cables short is best. It may be better and be cheaper
to re-arrange your room and use shorter cables than
to spend a fortune on longer cables!
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).
The ST30se amplifier does not have an output
protection device, which would degrade the
sound. So a prolonged short due to strands of
wire
touching
could
damage
the
valves
.
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.
Another alt
ernative is to use a test disc. If you are ‘bi-
wiring’ your speakers only two terminals, you must
use only 4 or 8 ohms, not both, as this will not load
the amplifier properly.
The STEREO 30se is designed to work with full
range, medium to high efficiency having impedance
of 4 ohms to 8 ohms. Speakers having efficiency of
lower than 86db will have greater difficulty in
providing a high sound level. But this will also depend
upon individual speakers, room size, type of music
and positioning etc.
Speaker impedance.
It is important to use the
correct speaker impedance terminals, as this will give
the best sound quality and power matching. If using
15-ohm speakers use the 8-ohm connections. If you
are unsure or “6 ohms” or “4 to 8 ohms” is quoted; a
rule of thumb guide is to try both positions. The
loudest being the best match.
Although your personal taste should be the final
deciding factor.
Do not connect to more than one pair of terminals for
each channel. If two pairs of speakers are required to
be connected, they must both be 8-ohm and
connected 4 ohm terminals. Contact Icon Audio for
more information. Damage could be occur if care is
not taken.
