Dear Nandric, all:
On previous occasions I have discussed the intimate relationship between cantilever type and damper/suspension composition. This thread is not the first time.
For example, you may be interested in reading this previous thread http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1264638758&openfrom&1&4#1 , in which I go into into the specifics of one particular Lyra cartridge design and its custom-made dampers/suspension. The tone of the discussion gets a bit argumentative at times (and I am partly to blame!), but the content of the information that I gave there is completely valid and accurate.
To go into a bit more detail, when we developed the Clavis and Parnassus, we chose a very unique cantilever material which was a type of duralumin that was reinforced internally with ceramic whiskers. It was an exotic but high-quaity material, very light and quite stiff. We called it "Ceralloy". During prototyping, we liked the basic sound of Ceralloy, but it had one obvious issue which was that there was a pronounced lift in energy in the treble region (3~6kHz).
Frequency response and perceived energy balance are funny things. Sometimes the frequency response tilts up but you don't hear it as such, (like at 8kHz and above), other times it may sound like the lower mids are bumped up or the bottom octaves are emphasized or whatever, but the frequency response doesn't show anything. All of this is further complicated by the fact that frequency response changes according to room temperature, groove radius on the LP, and cantilever excursion (signal level). A bit of a moving target, shall we say. At any rate, in the case of Ceralloy, however, you could both hear the extra energy in the 3~6kHz range and measure it.
We tried various ways to address this issue (because otherwise we liked the sound), and our final solution was to devise a three-piece damper system. Two of the dampers were sandwiched between the coils and the pole of the rear yoke (per normal practice, although some manufacturers only use a single-piece damper), but the third damper was designed so that it completely wrapped around the other two dampers and the coils. Externally, it looked like the coils were enclosed within a block of rubber (you couldn't even see the two normal dampers because they were concealed by the third, tubular damper). Very unique, very obvious to the eye, and if anyone has a Clavis, Parnassus, Clavis DC or Parnassus DCt, they should be able to see this easily.
The third damper did the trick, we were able to control the Ceralloy cantilevers successfully, and we sold lots of Clavis and Parnassus cartridges.
But time moves on, and so does technology. When it was time to design the Helikon (successor to the Clavis and Clavis DC lineage), we changed the cantilever material to boron. And we discovered that our 3-damper system didn't work; it was too much. Since the triple damper system was designed to counteract the extra 3~6kHz energy that Ceralloy had, when we applied it to boron, which didn't have extra energy in that range, we ended up with a suck-out. Makes sense, right?
So we redeveloped the dampers. New rubber formulation, new damper shapes, new suspension metallurgy. And no more tubular-shaped third damper to enclose the coils. Only two dampers, both between the coils and the rear magnet (we stopped using a rear yoke when the Clavis DC was introduced). All of this meant that the coils were no longer concealed, and became much more visible. Again, if anyone has a Clavis or Clavis DC as well as a Helikon, they should be able to see the differences in damper structure and composition, decisions that were driven by changes in the cantilever material. (AFAIR, the Clavis Evolve 99 had a boron cantilever and dual-damper system, and more closely resembles the Helikon.)
.
So, when I hear about people who intend to replace one type of cantilever with another that has quite different specific gravity or transmission velocity or internal lossiness or whatever, I tend to want to ask them if they have really thought through what they are proposing to do (smile).
OTOH, there are valid reasons to use a retipper on occasion, rather than staying with factory rebuilds. Maybe you broke your one and only reference cartridge precisely at a time where you absolutely can't afford an official rebuild. Maybe you have a cheap but fundamentally OK cartridge like a Denon 103R, and you want to find out how far it can go if you hot-rod it. Or maybe you find a splendid cartridge that you aspired to in your youth, but the cantilever is gone and so is the manufacturer (or they no longer make cartridges). FR, ADC, Sony, JVC, Technics, AKG and more, the cartridge may be a great design but if it no longer works and the original manufacturer is kaput, what do you do?
In life, (usually) everyone has to accept the consequences of their decisions, and to me that means that everyone should also have the freedom to make their own decisions, but just as importantly, possess sufficient and accurate information to base those decisions on.
If consumers can be given sufficient and accurate information regarding the tradeoffs of cartridges repaired (or modified) by retippers and the tradeoffs of factory-rebuilt cartridges - the pros as well as the cons - I am confident that the consumer will be able to make educated, properly informed choices about what to do with their damaged cartridges (or undamaged, as the case may be), and why.
kind regards, jonathan carr
PS. Stig Bjorge and myself (to a lesser extent) were instrumental in setting up the Japan branch of Ortofon in the 1980s. We know well about the damper specialist (aka "Rubber Man") at Ortofon Denmark.
