Uni-Protractor Set tonearm alignment

Dear Jj2468, the linear tracking tonearms - in any incarnation we have seen so far from Rabco, Denessen, Goldmund, Versa Dynamics, Air Tangent, Eminent, Forsell et al -displayed mechanical issues, periphery problems and stability problems which did always crippled their undisputed tangential advantage.
Most audiophiles who ever ventured into tangential tonearms later moved to tonearms with 11" or more effective length to approach kind of "best of both worlds".
Means they minimize tangential tracking error by means of increased effective length while keeping the kind of "practicability" of the pivot tonearm.
Thus minimizing the tangential "advantage" of the linear tracking tonearm.
I have had all the above named tangential tonearms in most all their incarnations in my system in the past 30+ years.
They all were promising and were able - some more, some less - to produce great sonic results (at least for moments or short periods of time).
It were certain sonic shortcomings apparent in all these designs plus practicability issues and long-time problems for many cartridges which ultimately drove me away from tangential designs.
A 11" or 12" pivot tonearm precisely aligned leaves little place to shine for a tangential design, which always and only builds on it's zero tangential tracking error - by sacrifice of other important dynamic and mechanical parameters in a tonearm.
Cheers,
D

Dear T_bone, you hit the nail on the head. For instance any derivation from a given tonearms design inherent offset angle results in an alternation of it's mechanical model - here it results in an additional breakdown torque, which has profound effects on the skating force. There are some tonearms out there which are designed in almost 100% compliance to Löfgren A/Baerwald IEC standard (all these tonearms being 9" effective length by the way). But then there are many tonearms out there which are not. And for those it is not just about aligning to certain null-points, but also that aligning to them does alter their resulting skating force (among other effects).
Usually one would say: o.k. just make the offset angle smaller and the skating force (resulting of the offset angle) will get less.
Not so as we have a design inherent offset angle and just apply a second one by twisting the cartridge in the mounting area in a different angle.
Thus resulting in a 2nd breakdown torque.
On the other hand there are tonearms like the Talea, which do feature an offset which is "free" to be determined on first glance, but which nevertheless follows Löfgren A IEC with clear given offset angle as specified by it's manufacturer.
This all should shine an additional light on the tonearm alignment topic and why there are different calculations, different focuses and different geometries.
Cheers,
D.

Dear T_bone, I really try to be funny but it is so difficult to succeed. So herewith my comment on the linear
tonearms. Thy look to me as a very handsome guy but in the
intensive care room. All those tubes...

Regards,

Dear T_bone: How many cartridges do you know? how many cartridges exist out there?, hundreds and each one resonate and performs in different way due to different cantilever build materials, different cantilever length, different cantilever shape, different stylus shape, different cartridge body build material, different suspension design and different suspension build material, different cartridge compliance, different cartridge weight, different, different and different all.

In the other side we have a tonearm that has its own resonance characteristics and different to other single tonearm out there due to different arm wand build materials, different headshell build materials, different arm wand shape, different tonearm bearings, different tonearm mounting base, different effective length, different, different, different and different all.

Each one of these cartridge and tonearm characteristics ( between other ones. ), one way or the other, has influence in the cartridge quality performance along accurate VT/SRA, VTF, Azymuth, overhang, offset angle, antiskate set up parameters.

Today no one here and no one out there can tell us in a precise way which and how is the influence of each one of those intrinsic cartridge characteristics, intrinsic tonearm characteristics and set up characteristics on the behavior and in the final cartridge quality performance for we can match for SURE one cartridge with one tonearm with the right set up on any recording.

The number of combinations of all those cartridge/tonearm/set up specific characteristics are almost infinity for we can say: " after our scientific research the only best match for this cartridge is this tonearm with this set up ", almost impossible we can do it.

But I don't finish yet, we have to take in count too the LP characteristics and characteristics on was is recorded there: off-center LP hole, waves all over the LP, different recorded velocities at different areas in the LP surface, thickness of the LP, resonance of the LP build material, etc, etc..
These LP characteristics has an influence too in the cartridge quality performance.

And now you think that an offset angle and overhang ( and we can ) different from what we can have through known equations ( Löfgren B, Baerwald, Stevenson. ) calculations choosing on those calculations whatever null points you want ( or what the tonearm designer choosed. ) could makes a difference that we can hear.

Adding thought to that: in theory ( for what you states in your idea. ) for each single cartridge/tonearm combination and for each one single LP we need different offset angle/overhang set up for be exactly " there ". Makes sense this for you?

I respect your opinion but I would like that you explain how is that? how can you/DT aisle/isolate that specific offset angle/overhang from all other each one cartridge/tonearm/set up/LP and from the combination of all those characteristics to know for sure that influence ( for the best or for the worst ) of the un-orthodox offset angle/overhang and that what we are hearing is because of them and not because the cartridge cantilever on playback is out of that offset angle set up that we made it in static playback condition or those tiny changes on VTA/SRA we have during playback due to LP imperfections where even there are tiny changes with the VTF too?

Where is that mathematic model that take in count all those different factors/characteristics that can tell us on playback ( motion not static way. ) which will be the quality performance level ( with lower distortions over the LP recorded area. ) in a cartridge and each one factor/characteristics " weight " in that quality performance level and of what kind is that influence?

I have no doubt and there is no doubt at all that you, Dertonarm, me or any one out there can't shows that great simulation model and IMHO till this happen ( I really hope some day its happen. I loved when this happen ) everything any one of us think or talk in the overall subject are mere speculations with no precise and proved foundation.

To make things " worst " we have to think that many of us likes some kind and different distortions and different distortions level even to some of us like higher distortions that other people or we are unaware to detect different distortion intensity levels due that our ears are not good enough, due that we are not trained to do it, due that we don't care about or due that our system has not that resolution level need it to.

We can go on on this thread making speculations of every kind but IMHO I think is useless.

Gentlemans, today we have what we have and nothing more. I hope we can improve in the future but certainly not an easy task on this whole cartridge/tonearm/LP subject. Today IMHO we have more questions than answers.

Regards and enjoy the music,
Raul.

We know how its sounds but we don't know exactly and for sure why/how sounds that way, we all have only speculations about but nothing more than mere in good faith: not proved speculations.

As some of you I would like to have/know the true proved scientific overall theory behind the why's on quality performance level between one cartridge and one tonearm running a recorded specific LP and not only to improve my knowledge level on the whole subject but because when we know that ( in the future ) then we have the answers to all and each one questions and finally the right cartridge/tonearm set up.

Till that day IMHO we have to make our best effort with the proved tools we have on hand hopping/thinking that the best is waiting for us in the future.

Regards and enjoy the music,
Raul.