Master of Innovation
The 1983 Orion bristled with new ideas – it offered tetrahedral bearings, damping by differential masses, enjoyed zero-point potential ( centroid ) balancing, a unique 10” geometry, adjustable azimuth, silver Litz wire, counterweighing optimised for effective mass and many other features never before seen in tonearms.
Orion was eventually superceded by the Cyalene and Omega arms. Now we introduce the forth incarnation of Helius super arm – Phaedra. True to its heritage, and shrouded in a cocoon of engineering art, Phaedra is a classic of the future.
The unending pursuit of perfection gives rise the inevitable question ‘what constitutes the next weakest link in the design chain’. From geometry to acoustic coupling and noise transmission, the tonearm is really an extension of the turntable. As the two work in unison and can’t really be separated, it seemed obvious our next step should be to match the engineering characteristic of our arms, with a turntable. To this end, we’ve launched two products, Alexia and Viridia ( with an entry level arm/turntable combination on its way for late 2019.) ideally matched to our arms.
Sophisticated engineering and an illustrious history are not the only advantages Helius owners enjoy. In keeping with the need to preserve audio heritage, we cater for collectors and connoisseurs, regularly reconstructing/renovating and servicing our classic products, regardless of age or condition. For this reason Helius products retain their value over decades and enjoy a following normally associated with rare marques of automobile.
Lengths – Choice of 10” or 12” effective lateral length (stylus to lateral bearing centre.)
– Vertical effective length 9.25”.
Tracking error – Unique Helius geometry
– For 12” arms, 97% of the record is played with < 1 degree of error. Peak error 1.85 degs
– For 10” arms, 92% of the record is played with < 1 degree of error. Peak error 2.57 degs
Bearings ( rolling ) – Tungsten, Ruby, Silicon nitride or ceramic
– Diametric tolerance 2.54 microns. Sphericity 0.64 micron
– Surface finish tolerance 0.008 to 0.010 micron Ra
Internal wire – Cryo Litz silver, 0.05mm strands, polyamide coating for reliable protection from short,
treated in liquid O2 for 1 week @ -190C.
– Copper is used in the case of the standard Omega.
– User choice ( customer to supply wire. )
Effective mass – Variable ( dynamic ) due to damping by differential masses and therefore ultimately dependant on cartridge compliance, typically though. 7g / 10g. Omega should be regarded as a low to medium mass arm best suited to medium to stiff cantilevered cartridges.
Other features:-
Counterweights – The main counterweight is fixed and as close to the bearings as possible to ensure low effective mass.
For fine tuning, we offer a choice of 3 minor weights. These accommodate cartridge mass ranges from
7g to 20g
VTA adjustment – Via screw and collar-clamp built within the base plate. Adjustment range 15mm/20mm max.
Non-coincident bearings to ensure differential resonance frequencies.
Damping by differential masses.
Tapered tube for maximal rigidity and minimal height above record. Sectional area decreases towards the front.
Internal silver wires continuous from cartridge to terminal plug.
Cables terminated via 2 x female phono/rca sockets contained within special case; this allows customer choice of interconnect cable to preamp and ensure maximum flexibility of cables is maintained for minimal interference with
turntable suspension.
Lengths – Choice of 10” or 12” effective lateral length (stylus to lateral bearing centre.)
– Vertical effective length 9”.
Tracking error – Unique Helius geometry
– For 12” arms, 97% of the record is played with < 1 degree of error. Peak error 1.85 degs
– For 10” arms, 92% of the record is played with < 1 degree of error. Peak error 2.57 degs
Bearings ( rolling ) – Silicon nitride
– Diametric tolerance 2.54 microns. Sphericity 0.64 micron
– Surface finish tolerance 0.008 to 0.010 micron Ra
( static surfaces) – Optical sapphire
– S/D surface finish ( smoothness) 60/40
– Optical flatness 5 fringe
– Parallelism < 5 mins of arc.
Internal wire – Cryo Litz silver, 0.05mm strands, polyamide coating for reliable protection from short,
treated in liquid O2 for 1 week @ -190C.
– Copper available on request.
– User choice ( customer to supply wire. )
Effective mass – Variable due to damping by differential masses and dependant on cartridge compliance
but typically 9g / 13g.
Phaedra should be regarded as a medium mass arm better suited to heavier or stiffer cantilevered cartridges.
– The inertial control applied by Phaedra over the cartridges increases with mass/stiffness.
Low mass/high compliant cartridges may prefer the Omega.
Other features:-
Azimuth adjustment – Achieved by locking the tube from behind the bearings.
Counterweights – 4 small slivers counterweights ( 8.5g each )to accommodate cartridge range from, 5g to 20g
VTA adjustment – Continuously variable over 6mm. Adjustment possible during playing of record.
Non-coincident bearings to ensure differential resonance frequencies.
Damping by differential masses.
Elliptical, tapered tube for maximal rigidity and minimal height above record. Sectional area decreases towards the front.
Inbuilt spirit level
Base clamping to secure final height setting.
Downforce – Adjusted magnetically for added security to achieve optimum trackability.
Internal silver wires continuous from cartridge to terminal plug.
An optical encoder is fitted to the underside of the platter – its counterpart is a laser emitter/optical sensor fixed to the subchassis with the control firmware is built into the electronics contained within the left hand pillar. Speed is referenced to the record and not the absolute motor speed ( as is conventional )
Radial (platter) velocity is evaluated/corrected in real time at 200Hz. { (33.333/60) x 360 encoder divisions )
For this reason, the Viridia is not affected by temperature variations; though the platter may expand or contract according to environmental conditions, this design ensures the turntable always functions at the correct speed.
2.825Kg – Though low mass compared to some, the point of the closed-loop speed correction is that the platter inertia cannot be so high as to prevent real-time correction. If it is, the motor will not have the torque needed to correct speed deviation in real-time.
Bearing shaft – 16mm diameter, through-hardened and tempered. Hardness 600 – 700 HV1.
Platter is suspended magnetically using neodymium magnets with a repulsive force of 4.8kg.
4 feet, adjustable in height (15mm) in the chassis base. For reasons of noise isolation, the front 2 are magnetically repelling pistons. Elimination of environmental noise is tuned to Frq >10Hz.
Parallel links tuned to 1 → 2Hz ( ultimately dependant on choice of tonearm as its mass affect the fundamental resonance. ) In order to provide maximal axial stability for the cartridge cantilever suspension, both the primary and secondary suspensions only work in the vertical plane.
As there is no physical contact between the platter and subchassis, rumble is not a relevant measurement.
Arm mounting plates are readily available for Omega and Phaedra arms and Rega arms. Blank units are available for cutting to accommodate any other arm of 9” or 10” lengths.
10.5Kg
10W
Record clamping weight
Tapped holes to clamp tonearm cables
Platter mat made to match the acoustic impedance of the LP vinyl.
Motor has its own suspension
Motor mounted on floating subchassis so belt tension remains constant regardless of subchassis suspension movement.
Damped composite subchassis
Mike Phalan
Gestalt HiFi
24 Sunlit Dr West
Santa Fe NM 87508
We would like to invite you to visit us at Gestalt HiFi and experience music like never before
We are by appointment to provide you personalized customer service
gestalthifi@gmail.com
808.640.8947
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