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icon Audio
MCTX
Moving Coil Step Up Transformer User Manual
The Finest Results From A Moving Coil Pick Up Cartridge
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 1/10
th
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.
