Fidelity Research FR-64 vs. FR-54

The FR 64fx is anodized aluminum where the FR 64S is steel.  The big difference is the moving mass - 20 g for the 64fx vs. ~ 30 g for the 64S.  The 64fx and the 66fx are the most expensive arms FR made.  They are specialized arms intended for low compliance MC cartridges.  (If you don't like them, it is probably because of cartridge compliance mis-match.)  I am using my FR-64fx with a Koetsu Urushi and it is a match made in heaven.  My Koetsu guy says the Koetsu cartridge was developed to match the FR-64 arms and I believe it.  They also work really well with Ortofon SPU cartridges.

In my post of 01/31/17, the one preceding Dover's last post, I should have written "because of", not "even with".  It is because I am using a lighter than OEM headshell and a very lightweight MI cartridge that the CW has had to be moved so close to the pivot.  Don't want to confuse anyone any more than necessary (heh-heh).

dcbingaman, Wouldn't it be the case that the FR64S and 66S are better suited for lowest compliance MC cartridges, because they are, respectively, higher in effective mass than the fx versions?  So, you might say that the fx tonearms are best suited for low/medium compliance cartridges.  I own an Urushi, too, and one of the reasons I bought the FR64S was to suit the Urushi, because I have read that the two are well matched.  So far, I haven't gotten around to trying that combo, however.

I accidentally came upon the posts by J Carr, in which, like Raul, he mildly criticized the FR64S/66S tonearms for their resonant properties.  Raul was not wrong in mentioning that he had J Carr on his side in the debate.  J Carr seems to prefer the later Ikeda tonearms and some others, to the FRs, and he mentioned that Ikeda himself prefers his later tonearm designs to those he designed for FR.  I think, in audio as in other pursuits, context is everything. I still have to go by what I hear in my system with the particular cartridge that I am using.

Nandric, Thanks for filling in the model number of the preferred Ikeda tonearm.  I've never seen an Ikeda arm of any type, but in photos I don't see any evidence that they incorporate damping any more so than the FR tonearms.  But I reckon the arm tubes may be internally damped, whereas the FRs are not.  Just a guess.

Lew, I'm sure Ikeda likes his newer designs better.  J. Carr apparently does too, and he is a pretty smart dude. I have never heard Ikeda say anything negative about his older arms, however, and the newer Ikeda arms are a refinement of the FR arms.  As far as resonant properties, I have a hard time believing that the cartridge can cause resonance in the armtube above 100 hz - there is just too much compliance in the cartridge attachment to the headshell and the headshell attachment to the arm through the collet.

I am keenly aware of low compliance cartridges pushing the arm around at low frequencies, however.  This is the biggest source of thin, tinny sound.  IMHO, uni-pivots just don't work well with low compliance cartridges for this reason - the cartridge can and does rock the arm back and forth in azimuth at low frequencies. What the FR arms have going for them is high mass and beefy, outstanding bearings that don't give.  They have essentially no freedom of movement in azimuth.  The bearings in the Ikeda arms are even beefier.  That is why they work well with Koetsu's, Miyajima's and Ortofon SPU's.  These arms don't allow the cartridge to push back and cancel half the bass in the groove.

BTW, I have an MDC-800 (The Arm) on a SOTA Sapphire and an FR-64fx on a tricked out VPI HW-19 Mk. IV.  I tried my Miyajima Shilabe (low compliance) on my SOTA setup first and wasn't impressed with the bass, (which this cartridge is known for).  I then switched it to an FR headshell and tried it on the VPI HW-19 Mk. IV.  It had better bass than my Ortofon Synergy SPU, (aka the Rach 3 ball-buster !), on the same arm and table.  

The MDC-800 has outstanding bearings, so I reasoned that I needed more arm mass and inertia about the cartridge.  I added 3 grams of weight to the cartridge end of the MDC-800, remounted the Shilabe to the arm and tried again.  This time it matched the VPI set-up for bass.  The weight increased the moving mass of the MDC-800 from ~13 grams to over 16 grams, and it made a huge difference in sound.  You can't stress cartridge / tonearm matching too highly.  Many high end cartridges and tonearms are just plain incompatible and can cause endless frustration and head-scratching for many, many vinylistas !!