| Arizona
Cactus capacitors.
On the very informational web site"Jeffsplace"
Mr. Shirokazu Yazakiof tells us
how he came to the development of the Cactus capacitors
and he explains the sound differences between the Red,
Green and Blue line.
The
complete text can be found with the following link:
Upgrading
of the coupling capacitor: The Red, Blue, and Green
Cactus Capacitors, True Fame of Made In USA
Below
is a summary of the article.
Simply
stated, I have felt the sound and the tone of the Red,
Blue and Green Cactus hermetic sealed oil-filled capacitors
by Arizona Capacitors, Inc., to be so desirable, and
I have loved them for their tone that is full of warmth,
depth, and sweetness. The unique very rich and organic
mid-low range of these capacitors brings out the healing
and the comfort of my favorite music.
Encounter
with Arizona Capacitors, Inc.
I
would like to describe my lucky encounter with Arizona
Capacitors, Inc., in early June of 2010. I had just
started to study how to bring out the full potential
of our reference Class-D amplifier design, in early
2007. At this early stage, I had reached the conclusion
that the quality of the capacitors for the low-pass
filter had major effects on the final sound quality
of the Class-D amplifier. The low-pass filter is made
of a pair of one inductor and one capacitor, and it
works effectively in providing the analog signal current
for driving the loudspeaker at the final stage of the
Class-D amplifier. It needs a particular specified inductor
and a signal use capacitor, 0.47µF, and so it
would be just like low-pass filter of speaker network,
with the only difference being the crossover frequency
is around 400 kHz. I suppose you could imagine the importance
of the capacitor used in the low-pass filter for getting
the most desirable sound.
Thanks
to the passion of the forerunner of tube amplifier enthusiasts
in Japan, I was able to get easily a lot of types and
brands of NOS vintage hermetic seal capacitors, like
Sprague Vitamin Q, also Sprague HYREL, Dearbone, Aerovox,
West Cap, and others, like the NOS Black Beauty and
Black Cat, because of their favor in the consumer market.
Searching for nice sounding capacitors has been very
interesting work for me, and I found out about the enormous
sound potential of NOS hermetic seal oil-filled capacitors
that were made for defense use in the USA. By the end
of 2009, I had reached the conclusion that my favorite
capacitor for use in this filter was a vintage oil-filled
capacitors by West-Cap, 0.47/600, that made for the
US military in 1967. As a coupling capacitor it also
remarkably improved the sound of my old WE310A driven
DA30 non-feedback SET, with its sound gaining in musicality
and with a fascinating and beautiful mid-low range.
It’s a NOS vintage capacitor, but it did not have
too much heavy bass or old fashioned tone like the famous
Sprague Vitamin Q.
Well,
Banno-san (my fellow engineer, who is not only a skillful
engineer of analog and digital circuitry even now, but
also he plays the piano very much, and has been playing
the cello now for more than five years) and I, decided
we had to find a currently produced capacitor just like
the West-Cap for our Class-D amplifier, when we started
Spec Corporation. Thankfully, I was blessed to come
across Arizona Capacitors, Inc., at that time, and succeeded
in contacting them, the day after founding our new Spec
Corporation company on January 7th of 2010.
Type
C 85805, Red Cactus
At
first we ordered a custom capacitor made of only Kraft
paper and aluminum foil that was our prototype of the
Red Cactus. Yes, the Red Cactus is a genuine paper in
oil (PIO) hermetic sealed capacitor. On March 15th of
2010 we received the first samples from Arizona Capacitors.
With these samples, we were able select several oils
to try for impregnation, to hear which best fit the
sound we desired. The
first Red Cactus’ tone was very impressive for
us, and the mid-high range was simply fascinatingly
beautiful, so pure, and sophisticated.
The
tone might fit best for chamber music, especially for
violin and female vocals, I believe. That’s why
I called it Red Cactus, as the attractive tone reminded
me of a certain beautiful Hollywood movie star from
the old days. Even
now, we use this Red Cactus as the main capacitor in
our top of the line amplifier, the RSA-F33EX, and the
Red Cactus is Banno-san’s personal choice for
its pure tone.
Type
C50309, Blue Cactus
The
type C50309, which I called the Blue Cactus, was developed
to compensate for some of the weakness in the low range
of the Red Cactus. The dielectric materials of the Blue
Cactus are made of the combination of Kraft paper and
Mylar film. Accordingly the construction of the Blue
Cactus was just the same as the vintage NOS West-Cap,
which I so loved. The greatest virtue of the Blue Cactus
is its recreation of the rich and powerful sound of
the vintage hermetic seal capacitors made in USA, and
so the sound has a gorgeous and strong mid-low range.
Of course, the sound of this Blue Cactus surpassed the
vintage West-Cap with the transmitted signal information,
especially in the mid-high range. In other words, we
could say the dynamic S/N ratio and frequency range,
were much improved to our hearing, I felt. We have also
mainly used Blue Cactus capacitors in ourRSA-M3EX amplifier,
and I suppose the rich timbre and the massive sound
of M3EX owes much to the Blue Cactus capacitor. I named
the Blue Cactus capacitor after the vast clear blue
skies of Tucson, Arizona, that I experienced at the
Pima Air & Space museum, when I visited on October
3rd in 2015.
Type
C50313, Green Cactus
The
type C50313, Green Cactus capacitor, was released in
the summer of 2014, as our latest Arizona Capacitor.
I wanted to achieve a brand-new sound for a hermetic
seal capacitor, and Daryl-san’s (the former general
manager of Arizona Capacitors, Inc.) idea was to increase
the thickness ratio of Kraft paper to Mylar film. Our
goal was that the tonal character, from mid to high
end, would be close to the sound of the Red Cactus capacitor,
a genuine paper in oil (PIO) capacitor, but with the
added benefit of a mid-low range that would be like
the Blue Cactus capacitor. It turned out the sound of
the Green Cactus capacitor was nothing like a vintage
capacitor’s sound, and the Green Cactus capacitor
has a clarity through its entire exceptionally wide
range. I feel somewhat like the Green Cactus capacitor
has the sound of the best polypropylene film capacitor,
but is still very organic and natural sounding, which
is something polypropylene film could never achieve
at that level. And so I believe, this Green Cactus capacitor
could easily fit in well for a high-resolution music
source in the present day. When I named the Green Cactus,
I was thinking of the majestic scenery of Yosemite National
Park in California, filled with granite cliffs, waterfalls,
clear streams, and its beautiful giant green sequoia
groves.
Cactus
marking and Outside Foil
I
would like you to know the true meaning of Cactus marking,
printed on the Red, Blue and Green Cactus capacitors.
This Cactus marking is the old logo of Arizona Capacitors,
Inc., and the marking side shows the outer foil of the
capacitor. The outer circumference of a tubular capacitor’s
body must inevitably be one side of its electrode, and
this is called the outer foil. The outside foil is connected
to one lead wire of the capacitor, and of course the
inner side foil is connect to the other lead wire. Sometimes
inductive noise can be induced on the outside foil by
some kind of external electrical condition, but when
the lead of outside foil is connected to ground, the
inductive noise flows into the ground. Also,
it is better to install the lead wire of the outside
foil into the lower voltage side, or closer to ground.
When
you use Red, Blue and Green Cactus, Arizona Capacitors,
let me remind you that each Cactus marking points out
the end of outside foil, and these capacitors have been
produced and managed under the quality control of Arizona
Capacitors, Inc. to be labeled in such a way.
Physicality
of Raw material and Tone Characteristic of Capacitor
I
remember well, when Banno-san said to me in early January
2010, after his hearing comparison test of a lot of
types of capacitors, including the latest high quality
polypropylene capacitors, that “It is just like
I heard the sound of the mechanical vibration, or some
kind of resonance, of the raw materials of each type
of dielectric or electrode itself.” Banno-san
could very clearly hear how the capacitor’s raw
materials have much affect on the mechanical and sound
character of each capacitor, I think.
Well,
the capacitor for signal use works like this: The signal
voltage is superimposed on the DC that flows into one
side of the capacitor’s electrode, and the capacitor
blocks the DC so that only the signal current is at
the other side of electrode. In this filtering process,
the fluctuation of the electric charge produces mechanical
vibration on the dielectric and the electrode. This
kind of vibration leads to a modulation of the signal
as it flows through the capacitor, I understand. For
this reason, the raw material of the dielectric and
electrode will be be very influential for the tone characteristic
of the capacitor.
I
fully agree what Daryl-san once said to me, that “Capacitors
manufactured with exclusively film, such as polyester,
polypropylene, Teflon, are described as fast responding,
often associated with harsh tonal quality. Additionally,
these (typically) dry units also exhibit sonic resonant
tendencies that can also yield unwanted effects on the
sound quality. Oil filled or impregnated capacitors
tend to dampen this effect, giving superior tonal qualities.
In addition, by combining various ratios of Kraft paper
and film, the tonal qualities can be manipulated to
a desired effect.” In the sound of the Red, Blue,
and Green Cactus capacitors, I recognize the common
desirable and comfortable tone character in these capacitors,
which partly comes from the from the character of the
Kraft paper. I suppose you know very well that high
quality Kraft paper is made of genuine pulp, and the
main raw material of the pulp is from a conifer tree.
When I think of such a conifer, I’m also reminded
of the simply natural and comfortable low range of my
Altec 414A, which I have loved so long a time. The fabric
the woofer was made of is the highest quality pulp from
conifers with a long fiber length. I regard Kraft paper
as exactly the same sort of natural material, and so
it comes as no surprise that the tone of the Kraft paper
is organic enough that it warms my heart.
At
present, undoubtedly metalized polypropylene capacitors
are the mainstream capacitor for signal use in speaker
networks. I fully agree that metalized polypropylene
capacitors have a modern and very neat tone, with fine
details and resolution, and I know very well that this
sort of sound might be accepted and highly appreciated
by a lot of music lovers around the world.
But
I have felt the tone of metalized polypropylene capacitors
don’t have the natural warmth of human touch,
and lacks the true naturalness of the hermetic seal
oil-filled capacitor that is made of mainly Kraft paper
as the dielectric. I
suppose it might come from the fact that the frequency
also has a level of characteristic vibration, and with
polypropylene it would be higher because of the high
Young’s modulus (hardness) and the small value
of internal loss. I think the metalized electrode might
emphasize the tendency.
About
the foil of an electrode, Banno-san and I, had experienced
the tone of aluminum, tin and copper under the condition
of the same dielectric material and oil. Tin foil’s
tone, we felt was insensitive and cloudy. The tone of
copper foil was too rich for timbre for our hearing.
We selected aluminum foil because of its natural and
organic tone for the Red, Blue and Green Cactus capacitors.
Once
again, we found out the importance of balance between
hardness and internal loss. Well, I would like to point
out again that while our hearing senses can easily recognize
these differences in tonality, there is not any measuring
method or tools that can describe why this is so. There
is much that is unknown about the world of physical
properties and the mysteries of natural materials, and
so listening must be one of our truths for analog technology,
I understand.
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