icon Audio MCTX User manual

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icon Audio
MCTX Moving Coil Step Up Transformer User Manual
TheFinestResultsFromAMovingCoilPickUpCartridge
Welcome to the wonderful world of Moving Coil
pickup cartridges!
Why use a Moving Coil cartridge?
In order to extract the maximum definition from a
vinyl record Moving Coil pickups offer several
advantages over Moving Magnet types (much has
been written about this on the internet). However the
output voltage is around 1/10th of a typical MM
pickup. This is too small to get enough signal from a
typical phono preamplifier, but as the total electrical
energy is about the same it is a simple matter to use
a “step-up” transformer to raise the voltage to the
correct level.
Transformers are an ideal way to do this as they
provide wide range of impedance matching
automatically.
They also have the advantage of not needing any
external power and do not degrade the sound quality
by generating unwanted noise and distortion like an
addition amplification would do. Most Moving coil
cartridge manufacturers prefer transformers.
The Icon Audio MCTX is a simple affordable solution
and is compatible with virtually all MC pickups.
Should I worry about impedance loading?
No, usually this is between 50-100Ω but is not critical
as there are different methods of measuring, but
nearly all MC pickups will work well.
When connected to a conventional MM pre-amp (47K
input impedance, about 3mV) a Moving Coil cartridge
with the MCTX transformer will behave in exactly the
same way as a Moving Magnet type.
The MCTX Story
Originally designed for installation in our PS1 and
PS3 phono pre-amplifiers, we found that many
customers were asking for these transformers in a
“stand alone” box that could be used with any phono
pre-amplifiers. So the MCTX was designed and
made.
Prior to this, some thirty years ago, we were fortunate
enough to visit the factory of a well known pick up
manufacturer in Denmark. The visit included various
seminars about the theory, manufacture and getting
the best performance out of Moving Coil pickups.
From many things we learned there were two
important points:
I, MM cartridges have a problem with resonance at
high frequencies, This can make for un-predictable
“peaky” results depending upon loading and
interconnects, and can produce more perceived
distortion and noise. Perhaps just one reason why
Moving Coil sounds more accurate.
2, Moving Coil cartridges sound better through a
transformer, rather than an extra stage of
amplification. This is because the impedance and
gain characteristics of a transformer are so well
suited to the job. Also, they are noise free, and have
very low hum.
Some phono pre-amplifiers have an extra gain stage
for Moving Coil cartridges fitted, but the results of
these can often be disappointing. The sound can be
mechanical and uninteresting. Whereas a good
quality transformer will add nothing, whilst giving a
true interpretation of the original sound.
Solid construction is important for protection against
noise and vibration. We use high quality custom
designed British made transformers using oxygen
free copper, drawn into extremely thin wire. It is then
hand-wound on to the rare earth metal formers.
These are triple screened with mu-metal for
maximum hum elimination. Then mounted on a
stainless steel and alloy chassis using high quality
gold plated PTFE terminals.

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QUICK SET UP GUIDE
1 Unpack unit carefully. Make sure that it is in good
condition. It is important that you keep packaging for
warranty/service return. If damaged contact your
supplier.
2 Position the MCTX carefully in your system, away
from devices with a mains transformer, and power
cables as is practical. You can check this again when
it is working. (See Hum and Noise).
3 Connect your turntable output to the INPUT RCA
sockets of the MCTX. The OUTPUT of the MCTX
should be connect to the INPUT of your MM phono
pre-amplifier (which may be built into your amplifier).
You will need a good quality screened interconnect
cable with RCA plugs to do this. Note: some
expensive “boutique” interconnects are NOT
screened, these will pick up hum.
4 The interconnect between the MCTX and your
phono pre-amplifier should be as short as is practical,
to prevent high frequency loss. One meter or less is
fine.
5 Most turntables have a separate wire for the
“ground” of the turntable arm and chassis, this should
be connected to the MCTX “ground” or “earth”
terminal.
5. You can now use the MCTX. It is working in MC
mode when the switch is “out”. If you change to a MM
pick-up cartridge the MC transformers may be
“bypassed” by pressing in the middle “bypass” button.
This is exactly the same as taking the MCTX out of
circuit. But more convenient
High Output Moving Coil cartridges
Although the output is higher than most Moving Coil
cartridges, they always lower than a Moving Magnet
type, so the resulting sound level may be low, often
with poor dynamic range.
The MCTX is ideal for High Output MC cartridges as
the loading is correct, and the transformers have no
difficulty with a slightly higher output. If required we
are able to add a small amount of attenuation on
request.
General points
1 Many problems with hi fi equipment involve
connecting leads and connections which are usually
either ‘bad contact, or Wrong connection’. So it’s
worth making sure that you have good connections
and that your leads are the right way round.
2 The output of an MC cartridge is very low,
typically only 0.0003V, and signals as low as
1/1,000,000V being audible, very small voltages! So it
is important to have good connections all the way
from the cartridge to the input of your phono stage. It
can be beneficial to remove and re-insert all the plugs
annually in order ensure the best connections. That
includes the wires to the cartridge and headshell plug
(if removable).
3 If you are using more than one cartridge the
“By Pass” switch will take the transformers out of
circuit enabling Moving Magnet cartridges to be used.
Hum and Noise
When correctly installed there should be no
noticeable increase in hum or noise at normal
listening levels. If you do notice an increase in hum
and noise check:
1 That the MCTX is not in the vicinity of a
mains transformer, this could be in the turntable,
amplifier or other unit. It may also be above or below
the MCTX. You can check this by moving the MCTX
into different positions whilst listening to the noise
2 If significant noise persists, it is likely that
there is a “grounding” problem. This could be in either
in the cables, or the turntable ground wire is not
connected, or one of the plugs has a bad contact or
not fitting properly. Occasionally RCA plugs will need
slightly crimping or tightening to make a good contact.
No maintenance is required, but may be
advantageous to occasionally press the “By Pass”
button a few times in order to clean the contacts.
The wire which forms the windings of the transformer
is about the same size as a human hair. This could be
damaged by resistance test of a “multimeter” or by
connecting it in a way it was not designed for.
Dropping the unit may also cause damage.
Specification & Features
 All hand wired point to point
 Silver plated copper PTFE audio cable
 No printed circuit board to ‘colour’ sound
 Suitable for pickups requiring 10-500 Ohms
 Low output impedance
 Matching pre amp 47k (30-100K) input imp.
 “By Pass” switch for MM cartridges
 Gain = x10/20dB (or x1 for “By Pass”)
 Frequency response 10hz to 20khz –1db
 Gold plated Input & output terminals
 Transformers made in England
 120mm W, 56mm H, 125mm D.
 Weight 830g
 For shipping 1.2kg 200mmx200mmx170mm
(Specifications subject to change)
icon Audio (UK) Ltd
351 Aylestone Road Leicester LE2 8TA
www.iconaudio.com
Ph ([phone] ([phone]

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Final Inspection
This amplifier has been carefully checked, tested and final adjustments made by Icon Audio in
Leicester.
It has passed our rigorous listening test and final inspection to assure you of optimum
performance and reliability.
Date …./…./….
Model ……….
Amp Serial Number …………………...……….
Customer ……………………………
Check transformer finish ……….
Audio test ……….
Check inputs/outputs ……….
Channel balance ……….
Serial No sticker and recorded ……….
Credit card receipt .………
Chassis linearity .………
Signed off by ……………………….
Notes: