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Due to the effects of Lenz's Law,
even if an advanced, pole piece-less magnetic system is employed,
the presence of conductive materials in proximity to the generator
and gap will still result in various problems..
True one-piece “mono-block”
construction fabricated from aircraft grade alloy ~
The Lyra Helikon has practically zero non-functional material in
the vicinity of the generator coils. It consequently has a rather
naked appearance, with no permanent surrounding body. Despite this,
there is a slide-on/off, see-through full-body stylus guard for
complete protection when the Helikon is not in use. The lack of
obscuring sides or other body parts also makes it easier to observe
the cantilever and stylus during installation and operation, effectively
improving visual confirmation and therefore reducing the danger
of damaging the delicate cantilever assembly. The material chosen
for the main structure is one of the hardest aircraft grade alloys
available. This ensures maximum rigidity and machining precision.
The surface has been painted and lacquered with a clear finish for
lasting appearance.
Internal cantilever-to-body direct mounting
system ~
The cantilever assembly of the Helikon (& Parnassus) is mechanically
connected directly to the main one-piece structure of the cartridge.
In other words, the rear section of the cantilever assembly is extended
deep into the body/mechanical grounding structure itself (rather
than the center or rear pole piece, per conventional practice),
and securely anchored in place by a bolt-mechanism, thereby eliminating
as many joints as possible. This arrangement improves the transfer
of energy between the cantilever assembly and the main structure
of the cartridge, and prevents depleted vibrational energy from
being reflected back into the coils, cantilever and stylus, where
it can cause modulation distortions which are time-delayed and therefore
inharmonic.
Balanced symmetrical field magnetic system
~
The Lyra Helikon uses a pole pieceless magnetic system. The signal
coils operate in a magnetic field created directly by two powerful,
precisely shaped disc magnets of nearly equal size, mounted fore
and aft of the coil gap - in the simplest and purest manner possible.
Unlike conventional cartridges, there is no big offset magnet to
warp and distort the magnetic field within the gap or affect tracking
ability, no pole pieces to affect the transfer of energy from magnet
to coils, compress dynamics, or add unwanted distortions and sonic
colorations. There is simply less there to cause problems. Unlike
other pole pieceless"ring-magnet" designs, the disc design
creates a more even distribution of magnetic flux across the entire
gap, and allows the magnet diameter to be reduced and the cantilever
length kept short. The lack of conductive material around the generator
and gap also helps insure that no unwanted magnetic fields will
be created via inductive effects, allowing the primary magnetic
field and generator coils to perform their task of converting mechanical
groove energy into electrical musical signal, without interference.
Non-conductive front-magnet carrier ~
The white front-piece of the Lyra Helikon visibly signals a break
with every other cartridge, including those from Lyra so far. It
uses a totally non-conductive synthetic material for this function.
The superior mechanical properties of this material have been augmented
through intelligent design of the actual structure and its interface
with the main body, creating a structurally stiff and rigid front-magnet
carrier that is superior in a magnetic, electrical, and mechanical
sense.
Chemically pure iron core, high-purity copper
coils and solid boron cantilever ~
The Lyra Helikon uses a 0.3mm diameter solid boron circular rod
cantilever, and dual-layer coils made of 6N high-purity copper and
wound onto a square chemically-purified iron former. This was to
obtain a medium output voltage which would be useable with many
of today’s pre amps, as well as a higher level of perceived
energy than the Clavis DC which the Helikon replaces. The internal
impedance of the Helikon remains a low 5.5 ohms, but produces an
output voltage of 0.35 mV at 3.54 cm/sec, zero to peak, 45 degrees
(Scan-Tech/Lyra normal measurement scale), or 0.5 mV at 5cm/sec,
zero to peak, 45 degrees (which is an alternative measurement scale
that is also commonly used). However, thanks to the chemically pure
iron core, the balanced symmetrical field magnetic circuit and the
lack of extraneous material in the vicinity of the magnetic gap
and coils, the sonic purity remains on par, if not better than equivalent
Lyra models of the past.
Dual elastomer dampers with internal unipivot
spring suspension ~
The dampers and suspension of an mc cartridge are very critical
parts for performance and also longevity of the cartridge. Only
years of experience and lots of know-how about the elastomer damper
and wire spring materials will make it possible for a cartridge
manufacturer to make the choices that provide a combination of good
sound, good tracking, and good mechanical stability. The Helikon's
spring-damper combination is not only capable at resisting the various
forces that impinge on the cantilever, it also creates a clearly
defined pivot point and reference for the cantilever and coils to
move around, making accurate groove transduction possible.
Low-mass, micro line-contact diamond ~
While there are several types of stylus profiles, all Lyra cartridges
use Ogura PA line-contact styli, because it is our conviction that
these provide the best tracking and detail resolution at all frequencies.
If set up properly, such styli also cause less groove wear.
Which brings us to the discussion of tracking force versus wear.
Although what we see and the tone-arm sees is tracking force, this
is not necessarily what the groove sees. Barring mistracking, which
can cause rapid damage, what really affects the grooves is the pressure
per unit of surface area. Even if the tracking force is light, if
the stylus contact area is small, the tracking force will be concentrated
on a smaller area of LP groove, resulting in higher localized pressures
and accelerated groove wear. Conversely, due to its sizeable groove
contact area, a line-contact stylus does a good job at distributing
tracking forces over the entire groove wall, reducing localized
tracking pressures and minimizing groove wear.
Apart from the aspects already discussed, the PA has other advantages
that are particularly useful when playing used or damaged LP's.
Because of its superior profile, the stylus will not only use more
of the groove wall, which makes it less likely to be disturbed by
localized groove damage, but it will also play deeper in the groove,
at depth not normally reached - or damaged - by other styli the
LP may have been played with previously. This will result in less
surface noise, and also better fidelity imparted by better tracking
of the groove walls.
The other aspect of the cartridge stylus that matters is the size
of the total stylus shank, not just the part that tracks the LP
groove. This ends up affecting tip mass, and consequently, the frequency
response and tracking capabilities of the cartridge. The higher
the frequency and the greater the stylus tip acceleration forces
involved (which are a direct result of the LP cutting velocity and
the physical condition of the groove), the more important it is
to have small stylus and low tip mass. Dropping the size and mass
of the styli and cantilever also confers audible benefits above
and beyond its measurable ones, as this can minimize overshoot and
improve the settling time. Doing so reduces the time window occupied
by ticks and pops, making them less noticeable to the ear.
Rhodium plated output pins ~
The output pins provide the electrical interface between the tone-arm
connectors and the cartridge itself. Normally these are gold-plated
brass or copper pins. In case of the Lyra Helikon we decided to
go for the hardest and most sturdy plating process available, namely
Rhodium. This makes a very tough, scratch-proof surface for many
years of trouble-free performance.
Sonically transparent coil-protection sheet
~
Most phono cartridges have enclosed bodies, and some of them also
have a vinyl cover to protect the delicate damper and coil area
from contamination by dirt and dust particles. Unfortunately both
of these methods badly affects the sound because it either creates
resonance or close in the coil area so the coils are acoustically
prevented from "breathing". Lyra cartridges have adopted
Japanese "washi" paper that breathes, and while it is
very effective protecting the coils and dampers from dirt and dust,
it still allows the necessary free flow of air and acoustic impulses
that are necessary for an open, free, and natural sound.
Medium output, medium compliance, medium
mass ~
We wanted to make the Lyra Helikon a superb performer that would
match well with as large a number of interfacing components like
tone-arms, turntables, as phono stages as possible. However, in
spite of the desire for a wide number of matching possibilities,
we didn't want to compromise the design and its peak potential.
The internal impedance of the Lyra Helikon is 5.5 ohms, somewhat
higher than previous Lyra designs, but still low enough to classify
as a low-impedance cartridge design. In synergy with the improved
balanced symmetrical field magnetic circuit, it produces a medium
(for an mc design) output of 0.35mV at 3.54cm/sec, zero to peak,
45 degrees (Scan-Tech/Lyra normal measurement scale), or 0.5mV at
5cm/sec, zero to peak, 45 degrees (which is an alternative measurement
scale that is also commonly used). The medium output of the Lyra
Helikon means that it can be used comfortably by most mc capable
phono stages or mc capable phono inputs on preamplifiers, including
those with tube amplification, without encountering problems like
poor signal-to-noise or lack of energy commonly associated with
low-sensitivity phono inputs.
The cantilever compliance has been tuned to 12cu which is a comfortable
level for most tone-arms (typically medium mass) available on the
market today. Compliance is a measure of the cartridge suspension's
stiffness. A stiffer suspension requires a higher mass tone-arm,
while a looser suspension (high compliance) require a low-mass tone-arm.
The Lyra Helikon can be used in any high-performance, rigid bearing,
resonance-free, medium mass radial or linear-tracking type tone-arm
with integrated head-shell and adjustable anti-skating force.
In spite of the fact that the whole mechanical structure of the
Lyra Helikon has been milled out of a solid block of aircraft grade
alloy, the naked and open "skeleton" design and the removable
see-through, full-body stylus guard, has allowed us to create a
rigid and strong structure with a medium mass of just 8.0g. This
in effect means that it will match just about any tone-arm on the
market, and also that the total mass of tone-arm and cartridge always
will remain within commonly accepted constraints and design limits.
This also concerns the ideal system compliance which has been discussed
above.
In spite of being "medium" in the respects discussed
above, the Lyra Helikon is by no means a medium performer. On the
contrary, we feel that it should be possible to extract optimum
performance from the Lyra Helikon in a far greater variety of systems
than most mc cartridges available on the market.
Cartridge total weight: 8.0 grams
Internal impedance: 5.5 ohms
Stylus: 0.08 x 0.12 x 0.5 mm natural diamond shank, Ogura
PA line-contact profile (3 x 30 um)
Cantilever: 0.3mm diameter solid boron circular rod
Recommended tracking force: 1.6 - 1.75 grams
Compliance: Approx. 12 x 10 x (1/1000000) / dyne at 100 Hz
Channel separation: More than 35 dB at 1 kHz
Frequency range: 10 Hz – 50 kHz
Output voltage: 0.35 mV by the JVC TRS-1007 standard, measured
at 3.54 cm/sec, zero to peak, 45 degrees (normal Lyra measurement
scale)
Output voltage: 0.5 mV by the CBS STR-100 standard, measured
at 5.0 cm/sec, zero to peak, 45 degrees
Recommended load (direct into RIAA equalizer amplifier or
head-amplifier): 100 ohms - 47 kilo-ohms
Recommended load (step-up transformer): 4 - 10 ohms
Recommended tone-arm: High-performance, rigid bearing, resonance-free,
medium mass radial or linear-tracking type with integrated
head-shell and adjustable anti-skating force.
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