|
|
|
Simaudio Technical Education
             
           
Updated: June 21, 2007
|
Simaudio Global Technologies
This section discusses various technologies, both proprietary and common-place, that
are found in various types of Simaudio MOON components, such as CD Players, Preamplifiers,
Power Amplifiers and Integrated Amplifiers, hence the term "Global".
VPI Process for Toroidal Transformers
Simaudio firmly believes that an audio component's power supply be outstanding - not just adequate
or substantial. However, one essential detail almost always ignored in the technical discussion of
amplifiers must be addressed here: The transformer's regulation factor. Audiophiles are all too often
interested with the power of transformers when comparing various amplifiers. The difference between
500VA and 1000VA means very little on its own unless a regulation factor accompanies the VA figure.
Simaudio uses toroidal transformers that have regulation factors ranging from 3 to 6 percent. Perfection,
in theory, would be 0 percent, but this isn't feasible. In the case of a fully regulated power supply,
the regulation factor can be overlooked, but this type of power supply would substantially drive up
both the price and size of the audio component. Transformer regulation factors as high as 20 percent
are common-place in the audio industry.
Transformers experience a multitude of losses, each of which will contribute to the degrading of the
performance of an audio component. Unfortunately, most high-end audio manufacturers have little if any
background in transformer design, and therefore, will simply order them from a transformer manufacturer
by simply specifying the VA, the different voltages and perhaps the regulation factor. The end result is
what you find in a majority of the audio equipment available; a low efficiency, a poor regulation factor,
high heat losses, high eddy current losses, vibrations and a great deal of magnetic field losses. All of
these negative elements find their way into the audio signal and reduce the sheer purity of the music.
The grade of steel used in the transformer's core will have a significant impact on the amplifier's sonic
character. The "M" rating defines the grade of steel used, whereby "M1" is regarded as the highest quality
grade of steel. The steel used in the transformer cores found in Simaudio components exceeds the quality
found in the M1 grade. It is a high quality steel from Japan which is slowly rolled with extreme precision,
possessing superb chemical purity and properties of losses. The transformer design itself is made with less
flux density than usual, thus reducing the sensitivity to electromagnetic disturbances. Furthermore, we use
a very unique process called "Vacuum Pressure Impregnation (VPI) on the core to reduce its mechanical micro
vibration that often disturbs the sonic purity in any electronic environment.
Chronologically, here are some of the significant highlights of the VPI transformer manufacturing process:
- The core is made from a very accurately rolled and cut steel.
- Cores are preheated to remove any moisture first.
- These cores are then placed into a vacuum chamber where -28 PSI is applied for 15 minutes, removing any
air pockets trapped inside the core structure.
- Epoxy resin is then released from a holding tank into the vacuum chamber, filling any microscopic gaps that may exist in the cores.
- Pressure is then applied at +30 PSI for 15 minutes, causing the resin to return to its holding tank. Chamber
pressure is then stabilized to a normal level.
- These treated cores are then baked at 300 degrees Fahrenheit for 8 hours.
- Core insulation is then applied for mechanical and temperature stress.
- All transformer wire is "Class H" type.
These custom toroidal transformers function at a very low temperature (the same as their operating environment)
due to their stress-free performance characteristics. They also have virtually undetectable vibrations and of
course, an exceptional regulation factor. The result of all this is an electronic component with better electrical
and sonic performance, as well as a much longer life expectancy.
Independant Inductive DC Filtering       (Simaudio Ltd. Proprietary Technology)
More commonly referred to on this website as I2DCf, this is a unique type of DC voltage regulation
that was developed initially for the MOON Evolution series of components that has found its way into many models in
the MOON Classic series.
A stage of I2DCf uses one inductor, and is dedicated to each inegrated circuit type component
(DAC, Op-Amp, etc.) in the audio circuit’s signal path. For example, the MOON Andromeda CD Player and MOON P-8
Preamplifier, have a total of 56 and 40 separate stages respectively of I2DCf.
Image #2
This unique voltage regulation circuit achieves better noise filtering, substantially lower THD, improved channel separation and
lower crosstalk, a reduction in jitter for CD players, and more consistent DC voltage throughout the entire circuit (see figure 8 below):
              Figure #8
An audio component using I2DCf has a dramatically reduced noise floor, a dead quiet “black” background,
a more realistic 3D portrayal of the recording and perfect level matching between channels.
Sheer realism ... the genuine impression that the musical performance is taking place in your very own listening
space ... your audio system feels as if its effortlessly running on its own, without any electricity.
Highest Quality Parts
Circuit design is a key factor to getting the best possible sonic performance, but only when the
design employs the highest quality parts possible, can this be goal achieved.
|
 
|
Image #3
Clockwise from the top left; Motorola high-current output devices, mica capacitors,
matched dual JFET transistors and Wima polypropylene capacitors.
|
 
|
|
 
|
Image #4
Clockwise from the top left; Surface mounted analog IC’s, capacitors, D/A converter and thin metal-film resistors.
|
 
|
Using these parts provides MOON component with a very long life span, and no forced obsolescence ...
and the sonic signature will remain constant for many many years.
Low Operating Temperatures
All Simaudio MOON componenents operate at temperatures well below what's considered common-place
in high-end audio. These low temperatures effectively put less stress on the high quality parts
used inside. This results in a much longer lifespan for these parts which leads to improved reliability
and a longer life for the component as a whole.
4-layer PCB tracings using Pure Copper
The advantages of this type of circuit board include better ground and power supply circuit layouts
resulting in a much shorter signal path and dramatically improved signal-to-noise ratio. A shorter
signal path is sonically more accurate and lends itself to the less potential for signal loss. As well,
a 4-layer PCB has extremely low impedance characteristics resulting in less sonic colorations, especially
in the case of output stage sections (i.e. output signal from a transistor).
Over-sized Power Supplies
With a typical power supply, as the current draw increases the available voltage decreases.
However, an oversized power supply will minimize this inverse relationship, yielding a voltage
level that barely decreases as the demand for current increases. This allows for significantly
improved performance. Essentially, a greater power reserve results in a more effortless sonic character.
              Figure #9
Extremely Rigid Chassis Designs
Meticulous attention is paid to mechanical isolation, chassis materials used, and vibration control.
These factors contribute to increased resolution and accurate reproduction of details, without any
harmonic alternation of the original music signal.
For example; cones provide minimal point of contact (image 5); Triangular pillars provide great strength and
support for heavy chassis (image 6):
Image #5
Image #6
This all results in exceptional mechanical grounding and the reduction of negative sonic effects of
external vibrations.
Extruded Aluminum Chassis vs. Stamped Metal Chassis
Precision fit, high tolerance, extruded aluminum chassis parts exhibit significantly reduced
mechanical resonances and provide for a more rigid construction which contributes to uncolored
sonic performance. As well, aluminum doesn't corrode which helps to extend the product's life
expectancy. Aluminum also provides excellent shielding from RF and EMI, both major causes of
audio signal degradation.
SimLink™       (Simaudio Ltd. Proprietary Technology)
This in-house developed protocol provides for communication between MOON components, allowing
you to control various functions of several components from just place. For example, if you switch one
component into standby mode, all linked components will also go into standby mode. As well, when you
adjust the brightness level of one component's digital display, the linked component's displays will
adjust accordingly. In a nutshell, SimLink™ provides for genuine ease-of-use.
Image #7
Balanced Differential Audio Circuitry
When using an unbalanced interconnect, the audio signal runs through both the center wire and the
shield/ground wire. Any noise picked up by this interconnect (ie. nearby magnetic fields such as
an AC power cord) will be reproduced by the amplifier and heard through the loudspeakers. Conversely,
a balanced interconnect has three separate conductors; one for the ground and two for the actual
signal. These two signals are identical except that one is 180 degrees out of phase with the other.
The audio information is not transmitted by either of these two signals, but in reality is the
difference in the voltage between them. When these two inverted signals on a balanced line are
input into a differential power amplifier (i.e. MOON W-7, W-7m, W-8), any noise picked up by the
interconnect will be eliminated since a differential circuit amplifies only the difference between
these two signals: Noise on a balanced interconnect will be equal on both conductors and therefore
not be processed.
Image #8
A balanced audio circuit will only be effective when properly implemented. This means identical circuit layouts,
each using electronic components with very low tolerances, for the two phases of the audio signal; A very costly
proposition but worthwhile expense. The end result will be an overall increase in dynamic range, increased headroom
at all frequencies, better signal-to-noise ratio and much higher resolution.
Capacitor-free Signal Paths
Audio circuits without capacitors (i.e. DC-coupled circuits) in the actual
signal path typically sound better. Capacitors are the single most detrimental
components to sound quality which can be placed in a signal path with respect
to sonic colorations. One benefit to not using capacitors is that more bass
information passes through the circuit. However, such circuits will also
pass along any distortion coming from the component connected to it. Therefore
an effective DC circuit must have enhanced protection. Another consideration
is that all capacitors, even those of the highest quality and tightest
tolerances, will deteriorate over time and consequently, change the sonic
character of a component.
Please refer to "DC–Coupled Amplifier Design" in the
Amplification Technologies Section
for a detailed example showing the effects of capacitors in the signal path.
Teflon Insulated Wiring
Teflon insulation is much less susceptible to long-term deterioration
from typical environmental factors; this is the result of its very low
dielectric constant; It's an excellent insulator against heat, moisture
and high voltage. This type of insulation also maintains lower signal
resistance and capacitance over long term use, thus allowing a
component's sonic character to remain constant over many years.
|