| Silk
Audio Supermalloy MC-step up transformer
Although
there are several good MM phono cartridges, or MC high
output phono cartridges on the market, there is no real
substitution for playing LP with true MC type Phono
cartridges. The superiority of MC cartridge over MM
cartridge is obvious. MC phono cartridge usually has
very small copper turn on its armature coil as compare
to MM cartridge thus it has very low moving mass, low
output impedance (usually under 50 ohm) and low output
signal (usually under 0.3mV) resulting in better bandwidth
and retrieve better resolution out of vinyl groove than
MM cartridge.
Since MC
cartridge usually has much lower signal output (around
10 times lower) than MM cartridge, additional amplification
device is needed before feeding the signal to regular
phono stage pre-amplifier. Two approaches to handling
this task are:
(1)
Active amplification can be done by using active electronic
components like IC, Opamp, Transistor or Vacuum Tube.
This amplification usually encounters noise and distortion
problem since the signal level is very small (usually
under 0.3mV) to the point of inherit noise floor of
most active components; therefore, the active (Head-Amp)
amplifier mostly utilizes high degree of negative feedback
in the circuit to minimize noise and reduce distortion.
This seems straight forward but there is another amplification
method (Passive) that is more simple and yield better
linearity.
(2) Passive
amplification can be better alternative to work at low
signal level (Step-Up Transformer) since it inserts
almost zero distortion, or noise to the signal. Basic
principle of Step up transformer consists of two independent
coils with different in copper turns. The differences
can be defined as ratio and if the ratio is step up
(eg. 1:10) amplification is obtained through the mechanism
of magnetic coupling. Step-Up transformer is passive,
so it offers linear property without any help of negative
feedback so purer signal transfer is realized.
But
not all MC-step up transformers are the same! SILK Supermalloy
MC-Step up Transformer is taken several steps to design
and build better transformer to bring the great property
of passive amplification to the extreme. Starting with
the heart of the transformer, that’s the core
material, we use the best Supermalloy Nickel/Cobalt
alloy core in the world to provide the highest inductance
with lowest copper turn to allow extreme Nano Winding
Technology that extend the frequency bandwidth with
lowest phase shift and highest signal transfer.
Nano Winding
Technology is implemented. It is our exclusive technique
developed in our own workshop that comprises of super
small OFC wires (much smaller than human hair) bundle
together to extend high frequency by increase the skin
area of conductor(skin effect). The copper wire is also
wound in perfect layer throughout the coil to help maximize
signal integrity.
Our
design is also aim to reduce cartridge distortion by
providing theoretical loading (true loading) down to
20Hz when most other MC transformers neglect this. Our
lab test has proved that although most signal information
on LP are consist of mid-high frequency due to RIAA
standard, ample loading MC-step-up transformer with
true loading down to 20Hz helps lowering distortion
on cartridge throughout audio band.
While we
offer SILK MC Step-up transformer in 5 standard models
each with different step-up ratio and loading impedance
to best suit for most MC cartridges on the market, we
also offer custom winding to match specifically each
MC cartridge to selected Phono stage pre-amplifier.
Unlike other component, different MC cartridge has very
different parameter and specification; therefore, requirement
to have a matched MC-step-up transformer is absolute
important to ensure maximum performance and sound. Think
of MC cartridge as a woofer driver and MC step-up transformer
as enclosure, it would be impossible to determine a
single best enclosure for every 8 inches woofer since
each 8 inches woofer on the market has such big variety
on its own specification. Our custom winding program
can ensure matching on load impedance and step up ratio
to your MC cartridge. Please contact us to determine
what is the best solution for your application.
SILK
MC-220A is very versatile model. It can be connected
in two ratio, with 1:10 step-up or with 1:20 step-up
When used together with a MM phono stage which has (the
standard) 47K input impedance, it will reflect a 100
ohm load with the 1:10 step-up.
With 1:20 step-up, it will reflect a 25 ohm load. These
two connections can cover the need of 97% of all MC
cartridges on the market.
Figure
1. Shows MC-220A, with 1:20 step-up, frequency characteristic
with 12K load. Linear response is from 10Hz to over
25KHz within 0.1dB While -3.0dB point is extended beyond
40KHz.
Figure
2. shows MC-220A, with 1:20 step-up, both frequency
response and phase response. Top trace is for frequency
response while bottom trace is for phase response. It
is evident that the phase is very linear and has smooth
transition with no peak or dip.
Figure
3. show MC-220A, with 1:10 step-up to 12K load. Its
frequency response is linear from 10Hz to around 20KHz
with small boosting after 20KHz and smoothly drop down
to -3.0dB at around 56KHz. This is surprising for most
audiophiles but if we compare our SILK MC-220 to other
MC step up transformer, the boosting in high frequency
of other step-up transformers are much more severe.
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