Specifications from Helius Designs, Evesham, Worcester: 1982

In recent times design engineers working in the field of pick-up arms and turntables have made staggering realisations in the physics of information retrieval from the vinyl disc. One does not have to look back many years to see that parameters of tracking error, bearing friction and effective mass, dominated pick-up arm design.

These factors barely scratch the surface of the science today, for now we have new considerations such as resonances, the linearity of energy paths and mechanical damping. These are now far more important concepts, and individually, various designs available do take one or more of these into account.

Never before has any attempt been made to combine all these parameters, and then gone even further to establish original design constraints. The Orion arm by Helius is the result of 15 months of careful juggling of every facet of pick-up arm technology. Despite the sophistication of the design, the arm remains easy to use and easy to set up.

But what are the requirements? Why is such a high level of technology needed? . . . . the answer quite simply is to eliminate colouration. The alternative title for a pick-up arm is 'Tone Arm', the 'Tone' part of this name goes back to the horn era where one could purchase 'hard tone' or 'soft tone' stylii depending on whether or not one preferred to hear any treble or wished to avoid listening to scratches. The same philosophy applies to the arm; it was observed that different materials could produce different sounds, attenuating or accentuating various parts of the frequency bandwidth. Sadly those days are not yet gone, we have proven with the Orion that there is much work to be done in this field. The magnitude with which the Orion surpasses all other pick-up arms is not small or subtle, but is blatantly obvious. The three most obvious areas of improvement when listening are the depth, spaciousness or ambiance present in the music, secondly the high dynamic range and thirdly the tight extended bass, free from intermodulation.

So, what is different about the Orion that makes it so good? Answering this is not easy because no one single parameter is allowed to dominate, every aspect of the design is interrelated.

The stylus sits in the record groove and traces itself quite accurately . . . this in turn is attached to the cantilever at one end, and the poles or coils connected to the other. Now comes the difficult area, the cantilever must obviously be supported by a fulcrum, and this supporting medium is responsible for transferring momentum in the form of vibrational energy into the body of the cartridge and hence the arm.

The coloration arises from the way this vibration reacts with the arm. Since energy cannot be destroyed, it must be carefully channelled efficiently to a place where it is harmless. If the task is not accomplished efficiently, then residual energy reflects back into the arm and causes resonance.

Specifically the design works by eliminating the static and dynamic intertial inbalances that the arm represents to the cartridge, and provides it with an ultra-rigid support platform. The movement of the arm, for whatever reason, is tightly controlled and damped accordingly to the cartridge needs.

To start off with, a neutral axis has been created running between the dynamic centre of the cantilever and the master bearing. The use of a unique bearing is protected by patent application. It takes advantage of the one merit of a unipivot, that is that all reactions in its one bearing, are rotational and not vibrational (if designed properly). It acts as a focus or an epicentre for energy dissipation. All masses and dynamic inertias are balanced around this point.

The use of a large massive bearing housing further serves to offer a lower fundamental resonance in the lateral plane. This damps the movement of the arm without having the serious drawback of fluid damping methods, since it does not offer an alternative energy path, thereby avoiding phase non-linearities. Most arms have a single fundamental resonance frequency since the bearings lay on the same plane. This affects the subsonic behaviour of the arm over record warps for instance.

The Orion incorporates the three ball race on a much larger and more sophisticated level. This design is the only true audiophile bearing, it is not the general minature race used in mechanical engineering. The three ball race is the only design that offers tetrahedral geometry, and as such has the lowest friction value achievable for a captured bearing. More significantly, vibrational energy is refracted out of the structure. The design prevents this energy from reflecting back into the arm where it will excite resonances and generate phase inaccuracies.

To ensure that the arm can differentiate between groove information and warps, we have taken advantage of the fact that grooves are cut at 45 degrees whereas warps occur in the vertical plane only. Because the vertical and lateral frequencies are different on the Orion, exitations at 45 degrees do not cause a high Q resonance peak, but rather a wider band low Q resonance. We must stress that today' quality recordings do contain subsonic information, it must not be assumed that everything stops at 20hz. Even in cases where severe filtering has been used, there is still information present (other than rumble) despite many dB down.

These ideas illustrate some aspects of the Orion arm, there are many other points that a brief visual examination of the arm will show. The overall result is a superbly engineered and executed design offering a level of technology unequalled today. Ultimately though, the sound is what counts and the differences between Orion and other arms is immediately obvious, no ear straining is required! There is little point in describing the sound characteristics, all qualities being relative, the only promise we make is that you will not be disappointed.

Manufacturers Specifications
Effective mass (vertical plane 8g
Effective mass (lateral plane) 12g
Overall mass 650g
Effective length 251cm
Overall length 315mm
Bearing friction (both planes) <5mg
Lead Capacitance 62pf
Suitable cartridge compliences 5-40 c.u.
Suitable cartridge mass range 4-25g

Review from Hi Fi Answers November 1983

Star Performer

Helius' top arm, the Orion, incorporates all they think important in arm design. At Little under £400, it needs to put on a good act

The days of the analogue LP are said to be numbered, but you'd never guess it from the number of high quality arms, cartridges and turntables that keep finding their way onto the market. And that surely is where the great appeal of the LP lies. Since we inevitably do a great job very, very badly when it comes to retrieving the full quota of musical information locked away in our record grooves, there is endless scope for improvement. That's more than you can say for digital.

Helius' Orion arm was introduced at the 1982 Chicago show, and since then it has steadily gained a growing reputation among audiophiles as one of the best tonearms available. Not that such perfection comes cheaply. An Orion will set you back almost £400, and beautiful finish and sleek good looks notwithstanding, an arm must be pretty special to command that sort of money.

Subjective performance I'll come to in due course, but having briefly touched on aesthetics I'm pleased to confirm that the Orion really does look like an outstanding performer with its long, slender two-part arm tube, massive bearing mounts, gold plated counterweights and satin black finish. It looks like a product that should work, and it feels right too.

Orion's effective length is longer that usual with a stylus-to-pivot distance of approximately 10 inches (25.4 cm), instead of the usual 9 inches (22.86 cm). This affords a small improvement in tracking error distortion (Helius claim less than one degree tracking error with optimum alignment), albeit at the expense of a marginal increase in effective mass. The substantial alloy headshell is slotted to allow accurate cartridge alignment.

Because of the Orion's extra length it is necessary to position the arm base a greater than usual distance from the turntable centre spindle. This poses no difficulties with either the Linn LP 12 or Pink Triangle turntables, nor are there problems with the cartridge alignment or the rear of the arm touching closed dust covers. Other turntables may be less well suited however. The Orion drops into an SME-type oval cut-out, except that it needs to run north-south. Thankfully Helius will advise on compatibility and pre-drill the arm board of your choice, but already I can envisage problems with turntables such as Oracle and Logic.

The arm base is a substantial component that really forms a tight rigid bond with both the arm pillar and turntable board. The underpart of the base has an oval sleeve that clamps the arm pillar so that it is fully supported all round. Once the arm has been fixed at the correct height with a simple cross-head screw, two allen bolts are turned to tighten the sleeve on the arm pillar, locking it rigidly into place. The only drawback here is time and effort. Once set the arm is in place semi-permanently, making quick adjustments to VTA impossible. In most cases you'll need to remove the turntable base in order to loosen the two clamping bolts, therefore the Orion is not really for those who like to fiddle with height adjustment, though the problem is eased considerably on an 'open plan' turntable like a Dais.

Unusually for a fixed headshell arm, cartridge azimuth adjustment is possible by loosening two bolts that secure the arm tube to the centre-bearing block.

Three gold-plated counterwieghts of differing masses are provided, which used independently or inconjunction should give optimum balance and effective mass for all from very light to very heavy cartridges. You'll need a set of stylus scales to set tracking force. Side thrust is applied by a thread-operated weight system on a roller bar, a system which offers low friction and minimum side effects.

Bearings

The bearings are one of the arm's special features, and have been successfully designed to meet the needs of low friction coupled with high rigidity. Typical Orions arms should achieve a light, smooth-flowing movement when adjusted for balance, as well as having imperceptible free-play. Each bearing employs three balls per cup, and the assembly is tough enough to allow cartridge fitting and removal while the arm is mounted on the turntable.

That said, the Orion is still quite delicate as any piece of precision engineering must inevitably be, so care should be exercised when tightening up.

Both counterwieghts and vertical bearings are arranged so that their central axis passes through the approximate position of the stylus/cantilever. This minimises torsional forces on the bearing and the 'throw-out' forces caused by stylus drag, which vary the tracking force. Consequently the Orion is more stable than many conventional arms and tracks with a noticeably greater sense of security.

In common with a number of UK arm manufacturers, Helius employ for the arm cable twin-core screened Beyer microphone cable, wired in quasi-balanced fashioned. The cable is non-detachable at the arm base and as a result there are only three solder joints between cartridge tags and pre-amp phonos - a good point, I feel. Soldering quality is good too - and if you have ever worked with Beyer cables you'll know how delicate and tricky they can be to strip.

Having already touched on the visual attractiveness of the Orion, I'm further pleased to report that the arm handles very nicely. I particularly like the well-raked finger lift and not-too-tight, not-too-loose arm parking collar. Small point to be sure, but important ones.

Listening

Much of the listening and evaluation work took place with the Orion mounted on a Linn turntable, although I spent some time with it mounted on a Pink Triangle as well. Cartridges tried were predominantly those from the Koetsu family including two Blacks, a Rosewood, and the new Red, plus my own Onyx Gold. Representing the opposite extreme was the lightweight magnetic Grado Signature Two.

My principle impressions of the Orion were always of a tight, clean, well-defined sound, with plenty of range and contrast. The arm always gave a free-ranging yet integrated sound, with a clear sense of pitch differentiation and tone subtlety. Frequencies were well extended at both ends of the spectrum, but above all there was a degree of integration that seemed to allow every cartridge to work at something close to optimum. The arm seemed to impose very little character on the sound, although there was a general tendency for it to sound analytical rather than euphonic.

Stereo information was widely spaced and vividly presented so that details of microphone techniques were clearly portrayed. Depth perspectives were excellently reproduced, and on suitable anciliary equipment I would expect the Orion to give an impressively deep and well-layered portrayal on good recordings.

Capping these qualities is a sense of ease and naturalness that makes listening to music a relaxing experience. The loudest and most complex passages reproduce in a controlled and coherent fashion, so even on the most outrageous 12 inch singles the arm appears well in control. The impression of effortlessness can give rise to the feeling that something must be missing, but more listening will surely show that everything is there. Indeed like me you'll probably find yourself hearing things in the music you never noticed before.

Nevertheless I can see a few people finding the Orion a little too clean and house-trained at times. And in that context it might not find favour with those who like their music to sound loud and raunchy. Tied in with this impression of a sometimes over-neat precision is the way the Orion appears to reproduce rhythm. In my system I find it less flowing and subtle when it comes to characterising passages of rhythmic complexity and differing impressions of pace.

I feel the bass performance may hold the key here - while it is admirable in pitch differentiation and extension, it perhaps isn't as direct and dynamic as it might be. Rarely did I feel the bass line really propelling the music along with the Orion, although this aspect is only noticeable when compared to an arm that performs outstandingly in this area. I know the designer of the Helius has his views on this point, and I know he feels he could achieve a more powerful fluid bass line but only at the expense of pitch differentiation and flatness. I make the observation because I've noticed it consistently with every cartridge I've used, and it is the one point where I feel a slight question mark can be raised - in my system at least.

In virtually all other respects the Orion is as good as or better than any other arm I've experienced to date. At its best, on naturally recorded classical material, the Orion breathed an almost electrostatic-like openness and neutrality into my system. The music sounded fresh, natural and very true to life. So here is yet another outstanding arm and one that in may ways sets new standards for low colouration and effortless reproduction.