Discussion in 'Audio Hardware' started by rgu2002, Jul 26, 2017.
Technics - 305MC
Stylus - Jico SAS
Audio-Technica - ART9
Stylus - Original stylus
T+A - C10
Stylus - AT-150Ti
You really do have a special talent!! Good on you
Ce n'est pas "Good on you"... c'est "Good for you", qu'on dit en englais.
But, yes, Roman does have good talent. He did the first one I sent to him VERY well, I am VERY satisfied. So now, I just sent him all my broken cartridges to repair for me. All will be upgrades from aluminum cantilevers to AT boron/Micro-Line, except I'll try one to AN titanium/Gyger.
This will be 6 cartridges, this time, more than I can use in the rest of my life. I am not sure why I am hoarding these (except I have a special attraction to cartrdiges, like a couple of other audiophiles I know), but I am looking forward to seeing and hearing how they turn-out.
I expect them all to sound better-than-new. First, for every one, the new cantilever and stylus will be an upgrade, compared to original. And, second, the coils are fully "broken in", compared to new.
Beg to differ Warren; "good on you" is a a term of congratulation and well done, according to the Collins dictionary. Given your liking for our friend from Moscow's brilliant work, do you think a modest cart like my Sumiko Pearl would be improved? Maybe it would be a waste of money but i would appreciate your view.
So how does one retip a stylus?
I just learned from Roman's description and pictures. He removes whatever remnant of the previous cantilever and stylus is still on the cartridge, then makes some kind of VERY small sleeve to hold a new cantilever (which might not be exactly the same diameter as the old one), and attaches the new cantilever and stylus assembly. I believe he uses epoxy, but the trick is that the parts must fit as tightly together as possible for the epoxy to be as little in quantity as possible.
Epoxy is somewhat flexible and has much less strength than the metal or sapphire cantilever material and Roman's sleeve material. So the new assembly has to be structurally rigid on their own, without the epoxy. The ONLY purpose for the epoxy is to make sure the parts don't move out of position. This is why his careful construction and assembly, before adding the epoxy, is extremely critical for good performance, reliability and sound.
I have been buying the replacement cantilever/stylus assemblies myself, for Roman, with his advice which ones to buy. But I think for most people, he will obtain them for the customer as part of the total rebuild price.
I apologize, I am a bit of a high-end cartridge "snob". I think it is a waste of money to rebuild a very inexpensive cartridge. It is going to cost about $300 to rebuild any cartridge, if it was originally $2000 or originally cost $300. So there is no reason to spend $300 again just to end-up with the same old $300 cartridge. Better to buy somebody's used and originally expensive cartridge, with a broken stylus, for about $100 to $200, then send it to Roman. Now, this one, with a total investment of $400 to $500, will be equivalent to a $2000 cartridge, a gigantic upgrade in sound for only a little more investment.
Now, there are exceptions. Some cartridges were cheap to buy but actually have GREAT sound. Many people love the Denon 103 and 103R, for example. I love the old Denon 103D and the VERY old GAS Sleeping Beauty. So, yes, if you really love your cartridge, then I recommend rebuilding it with a step-up in quality of cantilever material and stylus shape. Now, you have something you know you like, and an exciting upgrade to try.
Unfortunately, for me, there are many people who love the 103D and any other memorable MC cartridge I might want from the past. NOS or very good used "classic" cartridges have been going up in price, and always getting more and more rare. It was 20 years ago, that I could buy a like-new Denon 103D for about $350 (twice their original cost). Now they are just impossible to find in new or like new condition and the so-so used ones are $350 or more. But broken ones are only about $50 to $100. That is why I decided to try Roman's work. And, it was so wonderful, to have one of my broken ones transformed into BETTER than new, that I am going nuts buying used, broken cartridges. I send them all to Roman, to repair and upgrade, to Boron cantilever, Micro-Line or Micro-Ridge stylus. Then I just put them in my cabinet, to maybe use one-of-them someday.
Now, I am hoarding too many for a sane person to want to own. The good news, is that if I ever do break or wear-out a cartridge, I need only open my drawer and select the next one.
Thank you for this frank comment. At its best Aluminum sounds dry and boring and at its worst it magnifies sibilance and/or induces ringing. I'm really glad to see so much Boron in Roman's posts and I really wish someone would make Beryllium available again because it's on another level.
"Good on you" works in this context as well.
And, it's "anglais".
Wow, this is interesting because in my whole life, here in California, I have never heard anyone say "Good on you", except maybe a foreigner. It sounds like "franglais" to me.
Do you have any idea why Beryllium would sound different than Boron? I ask because one of my broken cartridges, a SAEC C3, originally did have Beryllium. Now I will replace the stub (leftover little piece of the cantilever) with Boron. I wonder what sound characteristics will not be quite as good as the original.
And, if anyone here knows anything about SAEC carts, can someone tell me what are the differences between a C1 and a C3? They have almost exactly the same specs, same materials, but the C1 was much more expensive. When the C3 started manufacturing, the C1 was discontinued.
The Young's modulus (a measure of the stiffness) is 1.46 times higher for boron as compared with beryllium. The Specific Modulus (the Young's Modulus divided by the density) is 1.16 times higher for boron as compared with beryllium.
What those numbers tell you is that for the same cantilever geometry (length, diameter, wall thickness) boron is better than beryllium. In particular (given the previous sentence) the breakup frequency for boron will be higher than beryllium.
The only thing going for beryllium is that it is possible to make really, really thin wall tubes out of it (and only Shure had that technology, back in the '80's), whereas it is impossible to do so with boron, and that gives beryllium the edge for that particular, alas defunct, cantilever geometry.
Another thing worth noting is that the specific modulus of boron is much higher than sapphire or ruby by a factor of 1.6, which is why I guess that most high end cartridge makers use boron.
Awesome information. Thank you. I am surprised Boron is stiffer (for the same mass?) than sapphire. But, I bet diamond is still the very best.
I also bet that sapphire or diamond will have to be a solid shank, whereas Boron or Beryllium could be a hollow tube, therefore a big advantage for mass and stiffness.
You are right about diamond. Young's modulus 2.90 times that of boron, and specific modulus 1.93 times. The only commercial cartridge that I know of that comes with a diamond cantilever is the strangely affordable Dynavector Karat, although I have seen Koetsu cartridges that have been re-shanked with diamond.
Some of the mega-buck Lyra cartridges (like the Atlas) use a diamond coated solid boron rod, although I don't know how thick the diamond coating is.
In general, if you keep the other parameters constant (like the cantilever length and mass), making the material into a tube makes it stiffer. As an example, a 12mil (0.3mm) diameter tube with an 8mil (0.2mm) hole is twice as stiff as a 10mil (0.25mm) rod, even though the tube is 80% the effective mass of the rod.
I have a Linn Asak .
New in 1978.
Still have it. Works ok. But obviously
In need of a retip.
It was used for 4 years then removed from arm .
Price to retip?
20% of build cost at Soundsmith at least.
Great info! Is Beryllium perhaps also more dangerous for the environment? I know that certain metals like lead were used in old oil paint to get certain colors but are now banned, although paint is in practice much more involved in handling than a cantilever.
I know that Van den Hul charges about $800. Roman charges about $400, including the parts. But you will have to ask him, because I am not sure. It really depends on your choice of what type of cantilever and stylus.
Regarding beryllium - the metal itself is OK; the problem with beryllium are soluble salts and beryllium oxide, neither of which is present in a cantilever. Plus a cantilever is a fraction of a milligram. Also the old Yamaha NS1000M loudspeakers, still highly thought of used beryllium domes for the midrange and tweeters. Finally the James Webb Space Telescope used gold plated beryllium as the mirrors The Primary Mirror JWST/NASA . So I would not get worried about beryllium cantilevers.
And lead is used by the kiloton in car batteries. At least until the electric car revolution takes place with fuel cell energy storage.
You put an Audio Technica microline onto a Technics cart? What did the owner say about the sound change? And did it weigh the same afterward?
I believe it may be ultimately attributed to what JW said about the thickness or lack thereof of the Beryllium pipe. Whatever the case, to my ears, the inner groove performance of my carts with Beryllium is simply fantastic and seems to be better than those with Boron. For this very purpose of comparison I've purchased an AT-160ml to compare with my AT-150mlx and an AT33ml-occ to compare with my AT-33ptg/ii to see what Beryllium can do. I realize that the 33ml-occ and 33ptg/ii are not exactly a 1:1 comparison but the shape/weight/layout are very similar. I'm going to swap the 160ml stylus to the 150mlx body once I'm fully familiar with the AT-160ml on its own.
One thing to keep in mind is that although Boron may be stiffer than Beryllium, the atomic masses of each element is as follows:
Lead: 207.2 amu
Aluminum: 26.98 amu
Boron: 10.81 amu
Beryllium: 9.01 amu
So Be is lighter/less dense and that could give it an edge assuming the pipe/tube design is sound. It's a 16.6% reduction in mass going from Boron to Beryllium. It may be defunct but I will continue to enjoy what remains (particularly the Beryllium domes in my Yamaha NS-1000x speakers)!
And based on those numbers, why even bother with Aluminum? So many threads on $ibilance and IGD..."I'm having trouble with...have you checked your alignment?"
Very interesting posts! How does Titanium measure in comparison?
The atomic weight of an element, which is what you are quoting is irrelevant. The density of a metal depends on the packing density of the atoms too (specifically the number of atoms per unit cell and the volume per unit cell). The mechanical properties are determined by the macroscopic parameters of Young's modulus, density and specific modulus - so work with them. The *real* figure of merit is the specific modulus, the square root of which is equal to the speed of sound in the material, and hence proportional to the resonant frequency of the cantilever.
Aluminium: Young's modulus 7e10Pa,Density 2700kg/m^3, Specific modulus 2.59e7m^2/s^2
Sapphire and ruby: Young's modulus 4.5e11Pa, Density 3980kg/m^3, Specific modulus 1.13e8m^2/s^2
Beryllium: Young's modulus 2.87e11Pa, Density 1850kg/m^3, Specific modulus 1.55e8m^2/s^2
Boron: Young's modulus 4.2e11Pa, Density 2340kg/m^3, Specific modulus 1.79e8m^2/s^2
Diamone: Young's modulus 1.22e12Pa, Density 3520kg/m^3, Specific modulus 3.47e8m^2/s^2
Note that beryllium is less dense than boron by 21%, not the 16.6% calculated from atomic weight.
So, the figures of merit (specific modulus) of different materials relative to aluminium, along with the square root (in brackets) - which is what determines the first resonant frequency of the cantilever.
Sapphire and ruby: 4.36 (2.09)
Beryllium: 5.98 (2.45)
Boron: 6.92 (2.63)
Diamond: 13.4 (3.66)
So the question still is: why use aluminium? Answer, it is much easier to work with than any of the other ceramic or ceramic-like materials. It is also much, much easier to make into tubes. For example, an aluminium tube can easily rival a solid rod of sapphire or ruby. It is ductile, and hence more forgiving of modest abuse as compared with other materials which snap. And it is easier to put damping structures up the middle of a tube to control the resonances. So aluminium certainly has a place in cantilever construction.
Back in the day (early 90's) that I was involved with Wharfedale, tweeter domes were made from aluminium for the above reason. But then audio fashion demanded a more "sophisticated" material, and they moved across to titanium - which has almost exactly the specific modulus of aluminium! So they had replaced an easy to work and cheap material with an expensive material - to absolutely no acoustic benefit whatever. I moved them across to using alumina (aluminium dioxide), which has a specific modulus 3.72 times higher, and pushed the first resonant frequency up to more than 35kHz.
From your numbers, I wonder why diamond is reputed to be the best material for a cantilever. It has higher specific modulus than aluminum. Whereas the other most desirable materials, boron and beryllium, have much lower specific modulus. Sapphire is even lower. And I thought that is better than boron or beryllium. Confusing.
What about that sapphire or diamond must be solid, but boron or beryllium can be thin, hollow tube? Furthermore, beryllium is easier to machine than boron, so wall thickness can be thinner - stiffer and lighter.
It seems to me that you really want to maximize 2 things - stiffness and lightweight. This requires a combination of highest specific modulus and best machinability (to optimize hollow tube geometry). Maybe the specific modulus of diamond is so high, that poor machinability is ok, and a very thin, solid shank is ok.
By the same logic, boron and beryllium have undesirable low specific modulus, but they can be machined to very thin wall, so they understand up being VERY light and acceptably stiff. Is this the right way to understand?
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