Discuss The Viv Lab Rigid Arm

As best I can make out from their website, the Viv breaks a fundamental rule of tonearm design (other than the tracking angle thing).

That rule is that there must be profound coupling between the surface of the platter and the mount of the cartridge. To this effect, there can be no slop in the platter bearings or arm bearings. In addition, the arm must be rigidly mounted to the plinth (and the plinth must be both dead and very rigid) such that any vibration that might occur at the platter will be in the same plane as that of the cartridge mount.

If there are any differences (or decoupling) between the plinth and the arm, it will be interpreted by the cartridge and perceived as a coloration.

The mechanical engineering problem here is very much like that of an automobile steering and suspension. Any slop that is present between the wheel and the steering wheel will result in obvious handling problems and can be dangerous. The stylus is doing much the same as the wheel on a car does as it is the interface between the mechanism and the media. It must be kept in perfect contact with the media and the arm can't be vibrating or moving in any way above the locus of the stylus, otherwise that motion will generate a signal.

The RS Labs is the same in that regard: it is not rigidly coupled to the bearing. I agree that’s another rule breaker. Now we have to listen to the Viv. In all the other respects in which underhung tonearms like these two are rule breakers, it is possible that the rules that they break ( minimize tracking angle error, etc) are themselves not as crucial to best performance as we have been taught to believe. I agree, the notion of coupling of the pivot to the bearing is a design element I would rather not forgo. But even there, there are many who use outboard arm pods with overhung tonearms, and there are several turntable/tonearm combinations that pay little attention to that coupling. We have gone over that idea more than enough by now.

I had the chance to listen to the 7” version of the Viv as well as the SME 3012 on a friends all Audio Tekne system (table was a TechDas AFV).  I will just support that the Viv arms sounded fantastic in this system, nothing to make me think that it is fundamentally flawed.  I have had so much musical pleasure with Kuzma and FR-64S arms at home that I am not motivated to change to a Viv, but I can understand why people really like these arms despite the “design rules” they violate.

Dear @melm : " the ultimate test is your ears and not some measurement. "

That depends on the kind of sound you want to listen: the one you " like it " even if is wrong or the one that’s rigth and like it.

Almost always when distortions goes a little higher we like it because we are listening to something different to what for 20-30 years we are accustom to and we really don’t care if distortions levels are higher because we are discovering a " new " kind of sound.

Normally those higher distortions comes as atransparent or very vivid at HF and as if those frequencies have no limit. There are other characteristics about.

In my case if my common sense says something is wrong then I don’t need to herad it: why should I if its wrong?useless but to each his own.

The reality is that those happy owners are wrong but as I said just don’t care because what they listen in their system just like it the more. Such is life but the really critical issue with all those owners is not that they like it listened sound but that they can't be aware or discern on those higher distortions and that could says that they really have not a tests proccess about and just don't know what to look for or even if some of them can discern on the higher distortions levels and as I said just don't care maybe because they already spend their money on it.

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

@atmasphere Your Statement makes the claim,

" That rule is that there must be profound coupling between the surface of the platter and the mount of the cartridge. To this effect, there can be no slop in the platter bearings or arm bearings. In addition, the arm must be rigidly mounted to the plinth (and the plinth must be both dead and very rigid) such that any vibration that might occur at the platter will be in the same plane as that of the cartridge mount. "

In my view there are points made by yourself that are believed to having been addressed by many, but in a analysis of a variety of designs, there are to be discovered elements in the designs seen that veer away from this.

I have made it known in previous posts, I am a follower of a Design that is in place to offer a version of being a Rigidly Coupled Interface or as you have stated (no slop).

I have gone to the lengths of achieving this through having adopted various measures. Such measures have evolved over a period of time, where opportunities have been discovered to capitalise on the Philosophy.

Today, I work with a Hard System, (non yielding) not any soft materials unless the Cart's Damper is to be classed as a soft material in use.

The Plinth in use is produced from Panzerholz, the Chassis is mounted on the Plinth with a 0.1mm Tolerance for the fastenings. ( A design is very soon to be put to use where the TT's Chassis will removed and the P'holz Chassis will be the Plinth).

The Platter Bearing has been re-designed and new parts are used produced from a modern material, with clearance tolerances of 0.05mm on the machining of a Bush. There is another ream process required to complete the fitting of the Spindle.

With Lubricant in the Spindle /Bush Interface, the Run Off for the Platter when measured is seen in the very low microns and is extremely quiet in operation. There is a new design being produced, where it is expected that a Run Off showing 0.009mm and lower is able to be achieved, along with even further decreased noise being produced.

The Tonearm design has adopted the use of a different Modern Material, as used in the Bearing Housing, this material has proven to be very valuable for the design, and has enabled extremely tight tolerances (I can't say more on this).

The Spindle to Pillar Distance is set to a distance that is within 0.01 of the Manufacturers Dimension. The Tonearm is set into the Plinth (no arm board) with retaining fastenings centred to the same tolerances.

The producer assures these Tolerances survive Transit once set.

In relation to the Mechanical Interface, this is the best I am able to get access to, for the monies I am very comfortable spending. With what is already realised and the the upcoming Bearing Upgrade, it is not possible for me to imaging I will be needing more from a Mechanical Interface on a TT.

There is also work done to the Signal Path, that has been carried out so that there is possibly zero impedance on the function of the Tonearm due to the Internal Wiring configuration. A not so common seen Wire is in use as well, but that is a different subject.

I intend on adopting these principles to all the TT's I own and intend on interfacing with the Tonearm Design. 

With the extremely low friction design for the Tonearm Function and Platter Bearing Function, the search becomes what other influences can add friction.

The Tonearm Designer is using the Ultra Fine Polished Styli as a measure to further benefit the mechanical interfaces produced on both Tonearm and Platter Bearings.