Fidelity Research cartridges

if tonearm is FR64 S version FR-7f will be better match.

in case of FR 64 fx both are good match.

Question was about Benz and FR.

7f and 7fz looks the same from compliance point of view. 

Although do you believe in these compliance figures?

If to multiply compliance of given for 7f roughly by 2 in order to get 10 hz data we are getting 14 cu.

Yes it is a lottery.
Although 35 grams of effective mass is a lot for majority of modern cartridges. 
I don't own FR-F7f but my Ikeda 9 CV is low compliance. So low that I think it's close to  Ortofon SPU and compliance figures are quite equal  of of 6 CV and F7f at least on paper.

S4 headshell with which FR 4S was sold weights 14,5 g (or it was supplied with 19 g headshell???)
So if roughly  to evaluate FR-64S + 7f :
35-14,5+30=50,5 eff mass, g
So if to go further and to compute desired  resfreq [Hz] 9 - we are getting if to use 11 cu --> 28,4 g  tonearm (Total)Effective Mass needed[gr] ; or roughly 35 grams tonearm eff mass needed in case of 8  desired  resfreq [Hz]

It seems that there are owners here in Audiogon of 64S + 7f or 7fz --> have you tested with test record lateral resonance frequency in your system? Could you please post here results?

Dear Nandric, if you mean Aidas brand cartridge, he's not Russian (I mean master) and it's mammoth tusk.  If you do mentioned 9REX could you compare it with FR-7fz? Which VTF you use for 9REX? 

I will try to revive Ikeda 9EM soon.  

IMO Ikeda took a as sample  Empire tonearm and made it better. As I understood he have improved it further after Fidelity Research. So he was follower of Empire. 
As about geometry my Saec 308sx works with weird geometry. So to stick to geometry as the holy grail isn't easy path.
I am till today feel embaressement about Saec due to bad geometry and yes I don't feel safe with it. Although it works so I will keep it despite bad math. 
 

My two cents about Ikeda 9 EM
Better than 9 CV. Different suspension design. Better sound. Very even and fluent. Even in mono mode :)
Although as one channel shot (open coil), I'll see final image after repair.

So will hunt next for 9 REX and  FR-7f

nandric, my CV was rebuilt by my friend ~ 1 year ago, if Expert stylus will fail ask him:  service et cartridgeretip dot com

As about suspension - EM has hollow white neoprene balls as part of suspension. Not balls to be exact it’s more looks like short white mushrooms.

In my 9 CV it’s less complicated - no "mushrooms" present.  

Suspensions are different.

If you speak about Ikeda cantileverless yes it's difficult to get it as new. Mine CV had some distortion in left channel. Not much but after a while it was evident that I have to look for service. In Ikeda canleverless is you start to get distortion ussually it doesn't mean that diamond is worn it means that magnet gap is filled with debris and coils can't move freely. You have to keep your very records clean if you want to use it for a long time without worries. Cleaning isn't the service which changes sound or Ikeda ideas. Also Ikeda used quite tricky method to align coils and to void vobble of stylus but it can be adjusted quite fast if it is known what to do.
Em price in Yahoo japan was circa 200 eur so I was too curious not to try. This time it won't be easy as master will have to do new coil but for such peanuts it's worth to try. Diamond is good. 

If to sum up records not convenient at all. Takes too much place and if to use cantileverless better no wraps and they have to be clean.
Hard life.

just try to push it a little bit more - up to 2,3-2,5g. It will be OK for you and your records. 

That is good news, thank you Nandric, now I do have plan B.
 

I can't compare MM against Ikeda cartridges against MM -transient response and and fluency of orchestral passages is in another level.

Thus if MC cartridge is in pair with any MM/MI cartridge I am skipping it.

It's not limited to Ikeda - I like SPU Gold Reference especially for jazz vocals. 

Also I have heard some prototypes MC frontcoil with electromagnet which was very special. 

IMO if it's good cartridge MC has to be superior. Don't get me wrong - it's my opinion, it's subjective to my hearing apparatus :)