Teach me about cartridge 'retipping'

it would seem to me that if a retipper/rebuilder has a good idea of the exact specs of the old cartridge cantilever and tip and suspension, to the extent materials are available, he can basically try to mimic the original spec, correct?

Do you think they can look at the cartridge and understand everything about design of the cartridge and copy all the calculations made by the original designer? How?

This is why a re-tipper is not always a cartridge manufacturer or cartridge designer, some of them can’t even design their own cartridge.

There are cartridge designers and they are not a re-tippers, they do not even re-tip their own cartridges.

of course never ever perfect, but i should think they can get fairly close unless unobtanium exotic materials are called for...

There are unobtainable parts almost in every high-end cartridge from the past.

Not sure there ever was a gold-plated boron pipe cantilever in production to begin with If there was, it’s the first I’ve heard of it.

Gold-Plated BORON Pipe ..
and Gold-Plated Beryllium PIPE ..
are Audio-Technica exclusive during the late 70’s- early 90’s period, but no longer available! This is one all time favorite model and this is another (even better). Let’s get closer. Very few people know that top of the line AT-ML180 was made in two versions, as you can read on the boxes one version is Gold-Plated Boron Pipe, another version is Gold-Plated Tapered Beryllium ...

Another example of Beryllium cantilevers from different manufacturer is Victor MC and MM.

Dug up this old thread when a friend recently was trying to get me to buy a Glanz MFG610LX

https://forum.audiogon.com/discussions/glanz-mfg-610lx

In it, I stumbled across this entry by Chakster. I couldn’t believe it. I still wonder if I am reading this incorrectly. I’m new here.

“The Azzurra Esoter comes with spherical/conical stulus and that’s why it is not expensive, but the MF generator is the same on all Glanz models, it’s is probably equal to Astatic MF-300 or MF-400. But Azurra is unknown and that’s why it’s cheaper than Astatic or Glanz. I got one as a present from Nandric last year, i have tested it and i was impressed, mainly because it’s easy to re-cantilever and te-rip them in Germany by Axel to upgrade this cartridge to another level! Axel can easity repair suspension as well (just for about 60 euro, i did it once with my NOS Glanz 71L).”

Seems like at one point, you were all for retipping rare and different cartridges, @chakster. In this thread you are gushing about it. What changed your mind?

I’m talking about specific models of Moving Flux cartridges from Mitachi in that topic. The reason I think all those models can be upgraded is because I tried them all myself and all of them are weak compared to their top model, one of the reason why the top model is indeed TOP is different cantilever and stylus. Axel tuned suspension on my 71L (with this huge prism aluminum cantilever) and I sold it, because the 61 was absolutely amazing (with completely different original cantilever and stylus tip). And Glanz 31L with classic aluminum cantilever was different too, better than 71L, but inferior in comparison to the extremely rare Glanz 61. So I think this particular MF series deserve a Boron Rod cantilever and it’s a huge upgrade, that type of Boron Rod is exactly the same cantilever you can see on many high-end MC from Japan in the 80s and even today. As I said from the start an inferior cartridge can be upgraded by re-tippers for sure, but a top of the line cartridge can’t be upgraded by re-tippers. You can put a Boron Rod cantilever with advanced profile on $150 Azurra Esoter MF (aluminum / bonded conical) cart from Mitachi and probably it will be like $1500 Glanz 61 then. But what you can do with Glanz 61? Probably nothing to make it better.

I'm not sure what a re-tipper can do with this this broken sample of the best AT moving magnet cartridge? I don't think re-cantilevered unit can be as good as the original, believers in proper refurbishing could try :) 

P.S. All carts (and pictures of them) are from my own collection.

Well, I can’t say I disagree.  When people want me to retip an Audio-Technica that has a missing gold plated cantilever I’m up front with them that I can’t get the part and I leave it up to them.

Also, I advise them to just buy a new AT OC9ML/II since I can’t retip those for the price of a new one—although the price has gone up now.  Those were once selling new for as little as $250.  
On the other hand, if they just need a diamond, I have put a new diamond on plenty of tapered gold-plated beryllium and gold-plated boron cantilevers.  My view is those are so rare—especially any beryllium cantilever these days, that it’s always a great idea to keep it going.  You can’t get beryllium anymore.  And gold plated?  Forget about it.  
With Audio-Technica, you also have to readjust the suspension.  They harden over time and often will not show separation greater than 20dB or so.  They have to be adjusted again and they will show 30, 35 and higher dB.  For this reason, an AT33ML OCC that I retipped with a tapered hardened aluminum cantilever was declared superior in sound by an AT33 aficionado and collector to an original NOS.

So, I do think that the above illustrates that just because a cartridge is NOS, original and untouched, doesn’t automatically mean it’s better and going to sound better than the same cartridge retipped with inferior materials by a conscientious and skilled retipper.   
The collector in that case sold off his NOS and kept the retip.  I think that says something because he was quite skeptical at first.  I can back this all up with emails.