Helius Omega Tonearm
Starting at only $2800 !
The standard version of the Omega is mechanically very similar to the Silver-Ruby
Model. The main differences being the use of tungsten bearings, copper wire and colour configuration. The standard version is anodised black with silver counterweights.
Technically the arm is very sophisticated, being dynamically balanced, damped by differential masses and having non-coincident bearings. In addition, it pays close attention to small but significant details ranging from bracing ridges machined
into the headshell, internal cue construction, silicon bias correction, collet clamping base plate, micro-adjustment of tracking downforce...... And many more features...
On top of that, its just plain gorgeous !
The Helius Ruby $4300
The Silver-Ruby Omega is the high-performance version of the standard model. Although mechanically similar, the tungsten balls are replaced with 12 large rubies that are formatted in the Helius tradition of a 3-ball race.
In this configuration, 3 balls form a triangle in a close running journal with a 4th sphere pushing down into the centre of the triangle forming a tetrahedral array. This constitutes that absolute minimal friction levels possible in a captured bearing, yet also ensures point contact on all surfaces.
The design is perfect for tonearms and was invented by Helius, to our knowledge it remains unique to us.
Coupled with the jewels is silver internal wire. A choice is offered of two types, either 0.25mm single strand silver working in 2 twisted pairs, or a finer gauge of cryogenically treated wire twisted in Litzed pairs. Each channel being counter-twisted with respect to its electrical mate.
The Cryo arm uses nearly 8 metres of silver wire.
Aesthetically, the arm is a visual negative of the standard model, being silver with black counterweights.
The design problem.
It is simple enough to design a platform at one end of a tube on which to mount a cartridge, construct a set of bearings, affix a counterweight to balance the other end, and call it a tonearm.
This might physically work, but itís like comparing a model T Ford with a new Ferrari, and it shows no real understanding of the physics involved.
Apart from the obvious requirement for the arm to follow the groove across the record surface, a tonearm must exert a significant degree of control over the movement of the cartridge body as the latter tries to vibrate in sympathy with the stylus and cantilever.
As these two parts vibrate, they impart kinetic energy through the body of the cartridge and into the arm. As the application of a force requires an equal and opposite reaction, it follows that the whole tonearm must try to react by resonating, or vibrating about the bearings.
The musical signal is generated by the relative motion of the cantilever with respect to the coils and magnets inside the cartridge.
The stiffer the cantilever mounting, the more kinetic energy is imparted, and the more prone the arm is to move in sympathy.
In a perfect situation, the body of the cartridge would be bolted rigidly
to a heavy mechanical structure, so the signal generated is purely
that of the stylus in the groove.
But the system is not perfect. The arm is pivoted, and tries itself to vibrate in reaction to the stylus. This secondary, non musical, component is `addedí to the primary signal waveform.
In other words, the signal sent to the amplifier is a compound of both the music and any extraneous vibration from the tonearm.
This constitutes colouration, disguising musical information....... Adding to some frequencies, and blurring others. Subtle background information is lost from the midrange, the treble can become harsh and bass either lost or accentuated.
Accuracy of stereo imaging is lost, transients are diminished and front-to-back depth is limited.
In short, the tonearm must be designed to ensure the musical signal generated, is only what the stylus sees in the groove !
Or to put another way.......... a tone(less)arm !!
The Helius solution.
There are two distinct arenas in the design of a tonearm. First is the easy one, to carefully optimise a plethora of minor, but important features such as tracking error, cables and internal wires, bearing design and counterweight.
These contribute to the overall quality of performance, but really represent the icing on the cake rather than constitute the design fundementals.
A more important consideration is the stiffness of the tonearm structure to limit and damp resonance. In other words, the unwanted vibration of component parts within the arm, and secondly to control extraneous motion of the arm.
Energy has to go somewhere, and will always take the most direct path. In the case of the tonearm, this has to sink into the turntable subchassis.
This means that all mechanical energy has to pass through the arm. Starting with a journey from the cartridge, down the arm tube and out through the bearings.
To maintain both torsional stiffness and resistance to bending in resonance, it is important to increase the surface area of the structure on the path from the headshell to the bearings.
To control the pivoted motion of the arm at lower frequencies, we damp Helius arms by differential masses.
A little considered point is that record grooves are cut at an angle of 45 degrees relative to the bearings, ergo the stylus does not function specifically vertically or horizontally as the bearings would indicate they should.
By designing a differential resonance frequency between the vertical and horizontal planes, the cartridge perceives an insurmountable inertial resistance. The cartridge sees an effective arm mass significantly higher than it is in real life, it cannot move in sympathy.
Dynamically, it therefore behaves as a rigid platform supporting the cartridge, and does not move dynamically to colour the sound.
The last thing a tonearm is, is a tube with a cartridge at one end, and a counterweight at the other !