If you were to design a tone arm, what would it look like and feature?

I really like the options a Removable Headshell allows for.

One option that the method allows for, is to be able to consider a variety of materials and weights for the Headshell to be selected for use as the interface.

Another option, is that with a little homework behind one, a selection of Cart's can be pre-mounted into Headshells and the Arm VTA/VTF can be recorded for each configuration and recreated at a very short turnaround if a Cart' exchange is desired. This is also advantageous if it desirable to keep Cart' > Headshells in a Cartridge Keep when not in use, as I do.

It is also easy to acquire a Headshells in a variety of materials and weights with a design that has a clamping collar with a fastening screw, that enables the Headshell to be loosened and used to align Azimuth to an optimum.

A few nice options pointed out that are available when going down this road.

There is also another side to Removable Headshell that is not so attractive, which is the 'Typical Design' that is seen on many of the Headshells available to be used in a multitude of Tonearms.

For the present-day performance levels of Cartridge being produced and the monetary values associated with them, it does not make any sense to mount them onto a Headshell that connects to an Arm Wand, where two generic devices to produce the connection are meeting and completing the overall assembly of the Tonearm.

Companies that have a long-term association with Particular Designs of Headshell connection have chosen to supersede the earlier designs with New Designs that are attempts to vastly improve the rigidity at the connection and substantially reduce flexion occurring over their earlier offerings.

Unfortunately, it would appear to keep the Company responsible for the New Designs, Marketing at a particular place in relation to competitors' offerings for the Market Place, these newer designs are not generic, and are limited to particular models of a Tonearm Wand only, this is a shame as it does leave the Older Designs needing a Bespoke Remediation if they are to be improved.  

As a person who over the past years has been very involved with being an individual, who has been trusted with being introduced to the designs of a few new produced tonearms. One of which is a substantially modified Tonearm, which does have a Removable Headshell and One that is a design I have been involved with from conception through to becoming a working model, that is a design that also has a Removable Headshell.

As a result of this involvement, I have had firsthand encounters at experiencing designs for removable Headshells and the improvements put in place for the designs for a Removable Headshell.

As a over exaggerated description a 'Typical Design' for Removable Headshell that  is commonly seen, is one that is behaving like a Flag at the end of a Flagpole. The Headshell, as a result of a lack of rigidity being engineered into the connection between Headshell and Arm Wand is functioning like a Flag when exposed to ambient conditions. For the Removable Headshell, this needs to be scaled back in its movements. It is Micro Flapping around as a result of the ambient forces encountered.

This movement, that is occurring, as a result of a loose fitting of the Headshell to Arm Wand connection is one that is with Latitude, there is an unwanted freedom, a freedom that has no pre-ordained calculation produced for it. The movement that is available is only present, due to the tolerances between generic parts. The non-standardised condition to be found at the connection, will allow for a Headshell to produce a movement in any direction the ambient forces dictate.

What is the worse is that these movements that are manifesting on the Headshell are at the end of the Headshell closest to the Wand and are at their best within the Male/Female connection at the coupling.

These movements when transferred to the end of the Headshell furthest from the Wand are an amplified movement and one that is taking place over the point the Styli is interfacing within the LPs Groove.

A Cartridge as a design has evolved over many years, and much of that design is to enable the Cart's function to be optimised, when known conditions are to be encountered. The conditions that are known are pretty much defined by the Cart' >Arm Compliance, Cart' Loading, as well as the impact of the Stylus within the Groove.

The Cart' as a design, using the knowledge I have gathered through investigation and discussions, is suggesting the Cart's in general have never been designed to be mounted onto a Structure that is non rigid, especially where the rigidity that is present, is to the point, it is able to produce a Circular or Elliptical Rotation as a movement generated from the supporting structure.  

Taking this a stage further, if a Tonearm that has a removable Headshell and the Wand has incorporated a 'Typical Design' as the method for attaching a Headshell.

The Headshell chosen might be a Big Price Tag Item, from a highly sought-after Brand. 

The Brand has a Generic Male Connection Part inset into the Headshell and the Arm Wand has another Generic Female Connection Part inset into the end of the Arm Wand. The connection between the Generic Part and Headshell or Arm Wand is already a point of connection that can have an interface tolerance issue, then the coupling of the two generic parts will bring further areas of concern for the interface and tolerances that are present.

With the above as a very common method used and the conditions being presented are a reality not fantastical, an individual then makes a decision to mount a Cart' that costs multi-Thousands. It is difficult to see how placing such a valuable item, with a specific design intent, is best served in use in such an environment, from my end there is strong suggestion there is a detriment present to the optimised performance from the Cart'. 

I don't confront the idea of mounting any Cart' on any Tonearm, it is the user of the equipment's choice for how they wish to select and set the parts up.

What I do confront is the notion that a particular method of selecting and setting up the parts is an optimised arrangement. 

I have plenty of knowledge of Fixed Headshell Tonearms and do not use them anymore, as an impression made from the experiencing a Modified Tonearm with a Removable Headshell has been very persuasive in my decision made to supersede the fixed Headshell Tonearm and not keep them in use.

As for the Removable Headshell Tonearm I use, I have been instrumental in encouraging a design to be produced, for a much-improved rigidity at the Headshell to Wand connection. I have heard this New Design as a A/B comparison, of which the New Design for the coupling has been a night and day difference to the betterment and there is no reason to want to remain with the original design, even though it is a little quicker to make a Headshell exchange.   

I have also been instrumental in encouraging a Tonearm designer / builder to consider a design for a Removable Headshell, that is one that is not an overhanging attachment that can have flexion and issues with rigidity as a result of the method of connection.

The design for this Tonearm has a Detachable Headshell that meets the brief and is without doubt from my observation and understanding the value of the known machining tolerances, a Removable Headshell that has an extremely rigid interface, and possibly functions as a much improved method than what is on offer from many fixed Headshell designs.

The times I have been present for the demonstration of this Tonearm, has a Tonearm in use, that is undoubtedly a device that has a Mechanical Function that is extremely accurate, of which a proportion of this is attributed to the design for the Headshell connection.

I encourage an individual with a curiosity, to look into this further, as the outcome of making a change to improve the mechanical interface at Headshell to Wand coupling, can be a night and day difference and one that is for the better.                 

The arm's rigidity, mass, bearing & damping all play a role in extracting your cartridges peak performance. The tonearm has to support the cartridge in its correct position over the entire record, while allowing it to move inward to the centre of the record and navigate any vinyl surface imperfections.

Every connection in a wire creates eddy currents and micro-arcing at the connection interface. This distortion is particularly harmful in a tone arm, owing to the fact the signal from the cartridge is the most highly amplified in all of audio. 
 

The same thing happens with physical vibration. Waves traveling up from the cartridge, instead of being uniformly and smoothly dissipated along the arm wand and into the body and base, are reflected back at the head shell/arm tube interface. Which is aggravated by the need for a fastening mechanism.

So it turns out there are a great many technical reasons why detachable headshells (and arm wands) are a bad idea. 
Unless of course you value being able to readily swap cartridges enough to make it worth the sonic sacrifice. In that case you really should just use a two or 3 arm table. But there’s always people who want to believe in the free lunch, a much more likely explanation as to why we see this obviously inferior design even on high end arms.

No matter the design, it would have a removable head shell. Many companies now have that type as standard on their most expensive models.  There is not terchnical reason for not designing the arm with one, but old traditions die hard.

An uninterrupted run of internal wire from the cartridge tags to the RCA plugs.

jagjag - An auto arm lifter (gentle) at the end of a record that does not thump the arm

My turntable sits within armreach of the main listening chair. The stylus never makes it past the first runout groove and is lifted. But if at the other side of the room......

@daveyf
I’d like to see an "affordable" tonearm that is able to do VTA on the FLY while the record plays ( the only way to do it so you can hear it).......and not lose its settings (VTF)

I believe of all the tonearms mentioned on this thread so far only one has this capability, and it is not the expensive VTA with remote control one that Larry mentioned. 8^0

Atmasphere ^^^ that is SOTA in my book. VTA on the FLY and not lose settings. A designer needs to think that VTF is important enough to make a design that gets over physics.

Just a thought and I will take this up with my son in law to be an industrial robotics engineer. Robots have gotten accurate beyond belief with motors and drive systems accurate to less than a thousandth of an inch. It should be possible I would think to watch the groove with an optical sensor and drive a tangential tonearm accordingly. This would be far more robust than whisker contacts. 
He will be home from China in 10 days and we will see if that idea is feasible given current technology. 

An auto arm lifter (gentle) at the end of a record that does not thump the arm

The Thales arm is interesting in design; it is a version of the Garrard zero 100 tonearm from the 1970's.  The theoretical disadvantage is having four pivots  for movement in the horizontal plane.  I also don't know if there are advantages or disadvantages to the twin arm tubes (rigidity, inertial mass).  Also, unlike the Reed arm, the Thales does not eliminate skating force because there is an offset angle to its headshell.

I've heard some very nice setups with the Triplanar arm and I certainly think it is in play among top designs.  I also heard a nice setup with a Durand arm.  Durand makes gimbal and uni-pivot arms; their top model is a uni-pivot arm (Telos, a model I have not heard).

For tracking geometry and other issues, the Thales Simplicity II/Statement are hard to beat.

^^ Triplanar seems to keep busy somehow- if anything more busy than they used to be.

Having made a number of recordings, some of which I have mastered to LP myself, IMO the Triplanar is currently the state of the art and has been for some time. But lacking that sort of reference I can easily see why someone might think otherwise.

@atmasphere  Thanks, Ralph...very interesting. Would you consider the servo still to be a continuing issue with such a design. Must say, the Triplanar is an arm that I very much like, it would be hard to beat it in a number of areas. Oddly, it seems to have fallen from favor these days.

Back in the early 80s I had a Rabco I modified. I used carbon fiber for the arm wand, and set up a more sophisticated servo system, using a capacitance in parallel with the motor.


This caused the arm servo to not quite stop and also not speed up like crazy- it would track the LP and establish a speed that kept the arm more tangential. I never got around the bearing issues of the arm and track.


But some years back I found a zero-slop slide on which the arm mechanism (designed for motion control/robotics) could be mounted.

So if price were no object I would use that slide/block system with a servo similar to what I used before: probably light activated rather than using metal whisker contacts. To this I would add something that was similar to a Triplanar in that everything could be adjusted and equipped with the hardest metal bearings available (which is what the Triplanar already uses). 

The Reed arm is fundamentally, a simple, captured bearing design arm.  The only complication is the moving base that maintains cantilever/stylus tangency to the groove and eliminates skating forces.  Optical sensors have been around a long time (e.g., Beogram 6000 from the 1970's) for controlling servo motors to maintain tangency.  I don't think this makes the Reed arm unduly complicated, but, it is a matter of debate whether its advantages are worth the trouble.  The big issue, to me, is the price and possible problem with fitting such a massive arm on a particular table.

An arm from the past that is interesting to me is the Air Tangent arm.  There is one very rare model that allowed for setting VTA by remote control while the arm is playing the record.  That would be the only practical way to set VTA on a record-by-record basis.  That might be fun, although I am still to lazy to do that level of fiddling around.

I have not heard some of the ultra-exotic arms that go to extraordinary measures to damp and control vibration such as the SAT arm or the Vector Superarm 9.  These are too expensive for my consideration, but, I would like to hear them anyway.

I like the Reed arms. They meet all of my requirements. The T5 is a bit over the edge. It is very complicated for minimal return if any. But, I have not seen or listened to one so I really have to reserve comment. In the world of mechanical devices simplest is usually best. 

ct05171,

All air bearings rely on very low friction of the main bearing to allow the cartridge to easily pull the arm along.  To some extent, conventional arms also pull the arm axially to a new position, but, they employ the mechanical advantage of a pivot, something the linear tracking arms cannot do.  At least theoretically, this means more strain than a pivoting arm.  I never encountered the problem myself, nor any friends using air bearings (friend had the same ET arm as you have), so this might just be a theoretical issue.  Any sensor approach, such as that of the Reed, that then employs a motor to make an adjustment has the theoretical problem of having to catch up with a wrong angle, with some possible overshoot, mechanical noise from operation, etc.  A similar approach to that of the Reed (moving arm base) is used by one version of a Shroeder arm, but the base is moved by the arm being pulled into the right position by friction (a different compromise).  

I like the sound of the air bearing arms I've heard.  They tend to have really good bass response--full and powerful without being muddy.  I suspect that comes from the high lateral mass resisting the lateral movement of the cantilever when tracking monophonic bass signals (that means that all of the groove displacement is translated into bass signal instead of some being lost by the cartridge moving side-to-side). 

^^^^^
Larryi - very interesting design that Reed T-5 linear tracker. Always liked the Reed products never owned.

https://competition.adesignaward.com/design.php?ID=68105

From their website.

Tonearm’s turning part is based on low noise thrust-sleeve bearing. For angular rotation limited rotation sectional torque motor is designed and built.

OPERATION / FLOW / INTERACTION:
Tonearm’s position is controlled by laser and linear sensor grid. When tonearm is operating, laser beam should point into a center of linear sensor array. LED indicator shows tonearm status.

This part with the motor and laser sensor grid sounds complicated to me; and who knows how reliable its going to be. I prefer air bearing linear trackers which are by themselves passive devices, their levitation comes from an external air pump, the movement solely by the groove friction. External pumps are easily exchanged at will.

Also just a note.
The cart lateral strain reference you mention in your post is not a general one but based on comparison to specific linear trackers. I can tell you that the one I use, the ET 2.5, has been measured to have half the lateral strain of my pivot arm due to its unique counterweight design. This allows the owner to use the highest compliance MM if they choose.

Cheers

I have no idea which design or elements of an arm will result in the kind of sound I would like.  I would like to hear the Reed T-5 arm out of curiosity because it does have a lot of design elements that address theoretical issues with tonearm performance.  By using an arm base that rotates, it achieves what linear tracking arms achieve without resort to air bearing or other such mechanisms to achieve tangency across the record surface (i.e., it does this without excessive lateral mass, and without putting lateral strain on the cantilever).  By rotating the base upon which the arm is located (moving the pivot point), the headshell also doesn't need to have an offset angle, so no skating forces are created).  The motorized base's movement is controlled by a laser that measures deviation from tangency. 

But, I have no idea how all of this translates into performance and whether the arm would work well with the cartridges that I like.

I want a tonearm like the E.A.T. F-Note, with Laser VTA and Azimuth adjustment, I also want it with automatic adjusted anti-skating, automatic arm lift, remote controlled VTA, remote controlled stylus drop and lift from any record tracks.

https://www.europeanaudioteam.com/en/e.a.t.-f-note-tonearm-wp000102.html

Remember the older gentleman who designed a weird tonearm that Fremer covered very briefly at AXPONA? And he needed funding? That arm.

@mijostyn  +1 on the Kuzma 4 Point.  Money always matters and Franc Kuzma has engineered a great solution at a reasonable price considering the performance.  It will be my next arm.

Take a look at the SAT and work backwards from that.

Im woking on a sota tonearm for $127.0000 will get back to you soon with pictures.

Millercarbon, it is Frank Schroder. Frank and Peter are in bed together (imagine that!). Frank's tonearms are very interesting and creative. I personally would never buy one. Like Unipivots his designs are a way of avoiding the precision of aligning bearings correctly the result being too many degrees of freedom and variables that are difficult to control. Frank Kuzma's  4 point design is far more elegant controlling all unwanted motions with the lowest amount of friction in an easy to build format. 
Daveyf, you are far too polite. Anyway, I would take the 4 point 14 and try to lighten the effective mass getting it down to 14 grams by using carbon fiber so that people with medium compliance cartridges ( the vast majority) could enjoy the use of a 14" tonearm.

@millercarbon. I guess you have no ideas on this subject. That's ok.
Anyone else...

Wait- this is a joke, right? Because "if money was no real object" then what am I doing designing anything? I thought that's what money was for- to be able to buy people to do stuff like this. When you get to where money is no object you don't spend all day fantasizing you just pay some dude and complain about delivery.

Especially when guys like Schroeder already figured it out way better than I ever could. Only, remember 'complain about delivery'? Schroeder's about a year out. Dang. 

Oh well, not to worry. I hear Ledermann's gonna start making Schroeder arms at Soundsmith.