LA RÉVOLUTION DE LA LECTURE ANALOGIQUE
Viv Laboratory produces the unique "Rigid Float" tonearm that is a product of the original thinking of Mr. Koichiro Akimoto. It is quite a revolution in tonearm design.
Typical Product Features of the Rigid Float (RF) tonearm.
- Absolutely no mechanical contact at the arm pivot bearing, resulting in clean, clear sound with wide dynamic range and no distortion in the bass. The Rigid Float uses a magneto fluid to isolate the tonearm from mechanical vibrtions in the turntable and absorb resonances generated by the cartridge.
- Unlike other floating tonearms on the market the Rigid Float has no additional mechanisms to stabilize the bearing. This enables it to float freely with almost no friction.
- The straight arm tube with zero offset minimizes side forces resulting in excellent channel separation, and very low distortion even when tracking the inner grooves of the record. No "ant-skate" mechanism is required.
- The anodized aluminium arm tube is fitted with three rubber “resonance rings” for damping. You may adjust the position of these rings to vary the sound.
- A Universal type head shell connector is fitted for any headshell to be used.
- The Standard “Nelson Hold” headshell supplied tightly grips the cartridge magnetic circuit, which is the most important part of a cartridge and at the center of which, stylus is located. With “Nelson Hold” the sound is tightly focussed and very low in distortion.
- The inner wiring is pure silver wire (4N) with a silk jacket.
- High quality Rhodium Plated RCA connectors with an isolated ""earth"" terminal are fitted.
- The tonearm does not require mounting holes to be drilled in the armboard. Simply place the tonearm in the correct position using the provided protractor.
- Rigid Float comes in three sizes, 7", 9" and 13" and two finishes Black/Metallic and Black/Gold.
- Tonearm weight 1.8kg
- Height from tonearm mounting surface to cartridge mounting surface 60mm with arm tube horizontal
- Mounting distances from spindle to tonearm pivot RFE (7") 215mm, RFS (9") 265mm, RFL (13") 370mm
- Diameter of base 90mm
(3) As (Fig-2 in ""RF Technical Description (B)"" ), straight tone arm would assure customers that absolute no inside force occurs at some certain point (Null position in straight arm) on record groove area by appropriate underhang adjustment.
Stylus tracking force adjustment
(1) Prepare separately available "Stylus cartridge tracking force meter" for tracking force adjustment.
Side Force Superiority in Rigid Float tone arm
"(1) Rigid Float (RF) with straight arm shape does not set any ""Overhang"" amount, but only reverse direction ""Underhang"", unlike many other conventional tone arm with offset angled “S” or “J” shaped products.
(2) Conventional tone arms with proper overhang, create typical point where tangential line of cartridge stylus is in parallel with record groove line but still partial inside force towards tone arm pivot occurs somehow (Force in dotted line to arm pivot), resulting eventually still in inside force. (Fig-1 in "RF Technical Description (B)"
(4) Fig-3 in ""RF Technical Description (B)"" illustrates how inside force would occur in offset angle type tone arm system.
Followings are representing figures:
(θ) : Head Shell offset angle
(α) : Tracking error angle
(μ) : Friction coefficient between record groove and stylus
(W) : Stylus Tracking (Force) weight
(μｗ・tan(α+θ)) : Inside force
(μｗ・cos (α+θ)) : Pulling force towards arm pivot
(5) In Fig-3 at ""RF Technical Description (B)"", tangential line of cartridge stylus is in parallel with record groove line (α=0), under which occasion, stylus pressure to side wall of record groove is theoretically 90 degrees, being no tracking angle error.
(6) However there is still pulling force, arising from cartridge stylus to tone arm pivot in oblique with amount of “μｗ・cos(θ)” and simultaneously, inside force amount of “μｗ・tan(θ)”, which means cartridge stylus is still pulled towards center of record disc spindle direction.
(7) Normally, as offset angle value of (θ) is around 25°, tan(θ) becomes 0.47, resulting in almost half value of total friction force is given to left channel record groove, reacting to cantilever base stem. even tracking angle error is zero point. ""
(8) On the other hand, in straight tone arm (Offset angle θ=0), inside force is only “μｗtan(α)” at any tracking erroneous angle area. if we set 10° as tracking error angle, tan(α=10°) is only 0.18 which is much smaller as inside force value than ones of “S”, or “J” shaped tone arm with offset angle.
(9) In general, as (μ) varies a lot in accordance with music cut signal on record groove, difference of inside force amount between “μｗ・tan(α+θ)” (Offset angled tone arm) and “μW tan(α)” (Straight arm) shows quite a few and, as it directly causes modulated sound distortion (As inadequate inside force causes to vibrate irregularly cantilever base stem where cartridge armature is located), reproduction sound of straight tone arm has much superior predominance against others.
(10) There is an Anti-Skate Device (Inside Force Canceller), available for offset angled tone arm which normally reduces certain constant value of inside force itself but is not in effect to reduce “Range of inside force deviation”, which means no way to solve this problem.
(11) In (Fig.2), null position of tracking error is set (By attached RF tone arm template, packed in product box for arm installment on turn table plinth surface) at just before the end of most inner record groove area where distortion gets the highest.
(12) Now, from stability point of view, tone arms, presumably a kind of bridge, sustained by cartridge stylus and pivot, the length between these 2 points is shorter the better but the thing is tracking error angle becomes vitally large when arm length is shortened.
(13) In straight tone arm, however, as offset angle (θ) is zero, shorter tone arm is now becomes available even by 7” length model which is almost impossible in “S” or “J” shaped tone arm, keeping much high motive stability and lower modulating distortion, developed by ViV Laboratory researcher and owner of Mr.Koichiro Akimoto. "
The stylus cartridge body (magnetic circuit) should stand still for accurate transformation of vibration into voltage.
The factors that shake the cartridge body are side force, tonearm resonance and vibration from base via pivot or from air.
Among them all, side force is the biggest factor on conventional tonearm with offset angle (about 25deg) and overhang.
The most significant is that side force varies in proportion to the fliction of the stylus tip and the groove.
This means you can't cancell the side force anyhow, even using anti-skating, mechanism.
Variation of side force leads directly to distortion, channel separation, forcus and so on.