Tonearm recommendation

Fleib -
Just the bit about the spring mechanism & dynamic balance.
I agree that dynamic balance helps to maintain constant track force on warped records, but if you are not playing warped records then static balance should be fine. In my experience dynamic balance can suck life out of the sound. For me optimum for the FR64S is a mix of both. As I said in my post above I have removed the spring mechanism from some tonearms and there has been an audible improvement ( on non warped records ) to my ears.

As far as the ringing goes - its overrated in my view. I have heard in my system at worst a little sharpness in the upper midrange ( this is what they refer to I presume ) but as I suggested in my post above in my experience this can be eliminated by careful set up - optimising the counterweight mass, headshell selection, cable, arm board material etc, getting VTA, azimuth & tracking force absolutely dialled in.
I see Jonathan Carr uses a wrap on his FR64S arm tube but I do not like damping on tonearms as a general rule as it tends to suck life out of the sound and at worst smear the sound, particularly spongy or soft materials such as rubber, heat shrink, etc.

Raul - instead of talking about distortions - it would be more helpful if you simply described your experiences with Koetsu's which is what the op is using, and what differences in sound you heard between various arms. Which arm do you prefer and how does the sound differ in your preferred arm differ from the FR64 with a Koetsu installed in both. 

fleib: Maybe I did not explain the right way ( as almost happens. ). What are in " game " here? only the static/dinamic balance design?

no, there are several issues that play an important role about and one of them is the type of tonearm bearing, its quality and its friction levels in that bearing.

The FR tonearms were not designed with today best bearings and certainly not with a friction as low as the one ( example ) by Technics vintage tonearms of 4mg.

This low friction bearings ermit  that the cartridge in the crests/valleys tracks in very gentle way putting at minimum the changes in VTF/VTA, these Technics are statics designs and not 12" long.
In a dynamic balanced design with the 66 characteristics the crests pushed harder the cantilever/suspension in the cartridge because the dynamic mechanism always is pushing in the other direction but the LP crest has more force.

Try to find a EPA-100MK2 and make all the tests you want it against the 66 and then return to enlight about.

Btw, any of you 66 owners please go with a good " technician " and ask that he ( in your face. ) open the 66 tonearm bearing case and you will see the kind of tonearm bearing you today are " hearing " and trusting in.


Regards and enjoy the music,
R.

Dear syntax:  """  still writing his ringing nonsense like a broken record. The usual pain for brain. Old men never learn anything I guess. Buy some better electronics. You are not a perfectionist. """

I can't argue on your opinion that it's Your Opinion and I respect it.

As any one else we all are rpoud of what we have in our home audio system.

You are extremely proud of what you own. Any one can " see " it when you took the time to those all system individual items pictures in your virtual system and I can see that you still like the same " noise/distortion generator ""

You own not one FR but both the 64 and 66 and additional you have the RX MS TT that's a terrible one ( yes I own it. ), a design| with several drawbacks: a platter that ring like a bell, motor unit by Technics/Panasonic but very bad circuit parts and circuit board on the motor/control unit, non damped TT design with a terrible mistake because MS choosed to put the four arm boards exactly in the worst place that is where stay the TT foots where all kind of resonances/vibrations pass through each foot and directly are transmited to the all metal arm boards, etc, etc. I can go on on those so many design faults. In those regards the SX  version is the same.
Of course, you like tubes and some times SS too and several other "  generators .. "

Like you I owned, own or listened almost all the cartridges you have but one of the Koetsu stone version and maybe other 1-2 cartridges you own.

Good for you tha are so proud ( like me. ) with what you have and speaks of what kind of distortions you are enjoying.

Now, please make a favor toall of us and put some light on how the 66 helps a cartridge to it can shows at its best. Why and how? where and which are those 66 advantages or unique atributes that are so good for a phono cartridge?

I already posted why not with a wide explanation here and in some other threads several years ago in the same way I did t with the MS RX/SX TTs.
I'm sure that if you have is because you know for sure those 66 advantages and the whys of each one advantage to fullfill the cartridge needs, so I ask you how the 66 cover each cartridge needs.

If you can do it will be appreciated ( I'm sure ) for all of us and if you stay in silence then for sure you have nothing on hand other that the worst kind of audiophile " runaway ":  "" I like it. ""

Regards and enjoy the music,
R.