Tonearm recommendation


Hello all,
Recently procured a Feickert Blackbird w/ the Jelco 12 inch tonearm.
The table is really good, and its a keeper. The Jelco is also very good, but not as good as my Fidelity Research FR66s. So the Jelco will eventually hit Ebay, and the question remains do I keep the FR66s or sell that and buy something modern in the 5-6 K range. My only point of reference is my old JMW-10 on my Aries MK1, so I don't know how the FR66s would compare to a modern arm. So I'd like to rely on the collective knowledge and experience of this group for a recommendation.

Keep the FR66s, or go modern in the 5-6K range, say a Moerch DP8 or maybe an SME.

Any and all thoughts and opinions are of course much appreciated.

Cheers,      Crazy Bill
wrm0325
Dear wrm0325: Unipivots? Moerch, Talea, VPI, Graham and some other unipivots are good tonearms. I own some unipivots and tested others too.

Years ago when the Talea appears for the first time somne one started a thread to speaks on that new tonearm and there not only posted many persons but included Agoner's that were beta testers of the tonearm and MR. Durand posted too.
Well I gave my point of view about unipivot tonearm designs and all its drawbacks/disadvantages, against non-unipivot tonearm designs like Triplanar or any other pivoted one, that does not really helps for the cartridge can shows at its best. I don'ty want to repeat what I posted there where I invited to the designer to put some light on what I posted but unfortunatelly he did not and stay in silence.

What is the first cartridge critical neccesity that asks to a tonearm: STABILITY with CERO TOLERANCE for the cartridge can ride " freely " the LP grooves modulations. That STABILITY reside/belongs primary in the tonearm bearing design  that not only must has low friction but totally tight with no loose anywhere in that bearing design.

By " nature " unipivot is an unstable design and we can't change it it does not matters what unipivot designers do about ( at least till today. ) and that unstability is reflected at micro levels when the cartridge is ridding the LP. We have to think in that huge demands that represent all the generated forces down the stylus and grooves modulations when cartridge is in the trackibg motion and those huge  ( every type of forces and its feedback ) forces and tracking must be controled by the tonearm bearing and it's not posible yet for a unipivot to achieve this main and critical cartridge/tonearm targets.

I'm not saying that unipivots are bad because sounds good but as everything that sounds good has different quality gradding and certainly unipivots are not at the top of that grading because that unstability only is in favor to help to generate  additional  distortions and " push " the cartridge tracking abilities against it when must be the other side around: to help to that LP ridding.

Every one thinks that unipivots has very low bearing friction when in reality is not in that way because all the tonearm/cartridge weight/mass is concentrated at only one point that not only means not low pivot friction but that everything  and everykind of distortions and feedback goes through that single point doing things worst that in a non-unipivot tonearm design and instead to help de cartridge goes " against it ". 

The Technics EPA 100 has the lower bearing friction of any pivoted tonearm I know, it's only 4mg even well regarded non-unipivot tonearm designs are much much higher as is the Dynavector 505/507 MK2: 50mg!, yes you read it well: 50 vs 4mg. Unipivots can't compare in this regards with the EPA 100 and obviously has not all itys advantages.

I own two top of the line Grace tonearms, one unipivot and thwe other with gimball bearing design. I made several tests where everything the same: cartridge, tonearm wires, IC cables, etc. the gimball always performs with better quality level.

Unipivots are knows for its fast, open and transparent type of sound but those are the transparency or " alive " that some us are accustom to: higher distortions and that's all.


I totally agree with atmasphere because at least in that regards that's my experiences with each single unipivot tonearm and I know that in the Kairos just can't be in other way because the tonearm bearing has the same unipivot principle:


"""  The Talea was very sweet but simply lacked the bass impact. No amount of adjustment brought it out.  """



That the Kairos likes more to folkfreak than the Triplanar does not change in any way the premises posted here. Triplanar is more faithful to the real music information with better definition and lower distortions on  the fundamental and harmonics frequencies and bass range and more important: RIGHT bass range reproduction is not only the foundation of  the home musioc sytem performance but what gives the exactkly and precise frame to all the frequency range.

I don't posted about to open a new window in this thread is and was only to share my experiences and of course that I can be wrong but if I'm you I mantain some distance from the unipivots if I want to obtain the best of my cartridges.


Regards and enjoy the music,
R.
....and no mention of a tangential arm in this entire thread.

Just an observation...don't mean to throw gasoline on anybody's embers 'out there'.  It's all preference IMHO, and where that leads you...and leaves you. 

The unipivot  has some advantages which are undeniable. Those advantages are reflected in the number of top performing unipivot designs.  One advantage is damping, a feature so highly touted in this thread. When SME came out with the model V, many design features were to control resonance. That included the tapered armtube and the fixed headshell. High end "contenders" in the '80s were Zeta and Alphason 100S - fixed headshells.  The advantage of a fixed headshell is to eliminate the physical boundary and its tendency to reflect vibrations back to the cartridge. This might not be an insurmountable advantage, but an advantage nonetheless.

By its nature, a fluid damped unipivot can easily be critically damped.  The potential to over or under damp a unipivot should not be considered a fault. Any arm can be set up improperly.

Most of the mechanical energy from the cartridge does not get converted to electricity. That's why top cart designs today use exotic materials and design features to dissipate energy. An elegant solution for excess mechanical vibrations from the cartridge is to dissipate down the armtube and convert to heat by the mass of the arm or plinth, or run it out of a foot.  The contention is, this is more easily accomplished by a unipivot; one clear path for vibrations to exit, while conventional bearings are a two way street.

The task of a tonearm seems impossible and contradictory, to be a stable platform while completely free to move laterally and vertically. Two dimensions of movement is an oversimplification. If an arm is moving laterally and vertically at the same time, the movement is angular or three dimensional. Are conventionally pivoted arms necessarily more detailed and exact?  I think performance defies that generalization.

Our Mexican friend likes to use the word distortion.  This is meaningless without supporting evidence. The Dynavector 507 II is a bi-axis design with intentionally high inertia laterally, and low vertically. This type of  inertia scheme is used by the DP8, apparently to good effect.

I'm not writing this in support of arms I haven't heard, but an arm designer shouldn't be expected to answer ignorant, unintelligible assertions.

Regards,

Post removed 
Dear asvjerry: Nothing is perfect. Tangential, unipivots and pivoted non-unipivot tonearms designs has its own trade offs.

In theory tangential tonearms must be the best alternative but as always in audio when that theory goes to reality during playing that theory can't be confirmed because unfortunatelly the analog experience is way imperfect and theory comes and has foundation on perfect world.

That's why no single tangential arm I heard it can gives us the right bass range with the definition, precision, tightness and transparency that a well damped non-unipivot pivoted tonearm shows us.

As  I said the name of the game are those trade offs with tonearms designs and whcigh of those trade offs do lees harm to the cartridge needs for it performs at its best.

I'm for the well damped pivot tonearms and from this kind of design my choice is for the non unipivots.

The real and main subject here is: which are on each one of us the prefered trade offs?, sounds easy but way hard task we have.

regards and enjoy the music,
R.