Medium Output MC Phono Cartridge
Fourth generation Scan-Tech cartridge design ~
The Lyra Helikon is the first cartridge of Scan-Tech's
fourth-generation design architecture. (The first three generations were the Tsurugi (1985), the Lyra Clavis (1991), and the Lyra Clavis D.C. (1994). Even
though there are other Lyra models with different features, the above listed models represent the major progress in Scan-Tech/Lyra cartridge design
The Helikon's most notable advance is in the
elimination of as much conductive material as possible from the vicinity of the generator and gap. Due to the effects of Lenz's Law, even if an advanced,
polepiece-less magnetic system is employed, the presence of conductive materials in proximity to the generator and gap will still result in various
“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
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 polepiece, 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.
field magnetic system ~
The Lyra Helikon uses a polepiece-less 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 polepieces 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 polepiece-less "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
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 preamps, 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
line-contact styli, because it is our conviction that these
provide the best tracking and detail resolution at all frequencies.
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
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
particularly useful when playing used or damaged LPs.
Because of its superior profile, the stylus will not only use more of
groove wall, which makes it less likely to be disturbed by
localized groove damage, but it will also play deeper in the groove,
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
response and tracking capabilities of the cartridge. The higher the
frequency and the greater the stylus tip acceleration
(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 measureable 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
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
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