degradation of magnet in Troika MC cartridge???
- Thread starter jeremy roebuck
- Start date
YNWOAN
100% Analogue
Gerald, none of your 'extended research' contradicts one word I wrote (unless you feel the OP's cartridge is likely to have been heated to over 220 degrees C). No doubt an off-shore wind turbine and a MC cartridge share many similarities, but to spare you further research I have found this simple guide that will answer most of your questions:
Darth Vader
From the Dark Side
FYI Magnets can work waaaay above that 220 C. For example Sm(Co, Fe, Cu, Zr) (sintered) magnets have a Curie point of 800 C. Thats the temperature at which they lose magnetism.
I don't know what magnetic material is used in the Troika but my DRT XV1-s uses 8 small ALNICO magnets and that material has a Curie temperature between 700 - 860 C!
I don't think I have much to worry about apart from that naked boron cantilever!
Cheers,
DV
I don't know what magnetic material is used in the Troika but my DRT XV1-s uses 8 small ALNICO magnets and that material has a Curie temperature between 700 - 860 C!
I don't think I have much to worry about apart from that naked boron cantilever!
Cheers,
DV
Daniel Quinn
Banned
ywoan It would seem your belligerence is getting in the way of your ability to argue .
I didn’t contradict what you said , I questioned why the certainty expressed by you was based on paucity of explanation and wondered why the o/p faced with one form of dogma should replace the dealers view with another dogma .
Nothing you have said will assist the o/p in deciding which dogmatic opinion he should take on board , should be replace the dealers rhetoric for yours .
The purpose of my post was to show that demagnification exists in permanent magnets and anybody who wishes to catergorically state this does or does not have audible consequences really should have something better “than because i say so”
I don’t hold myself up to be an oracle on hifi matters , but if I did i would sure as hell make sure i knew what i was talking about and wouldn’t rely on rhetoric or pictures of my arse .
I didn’t contradict what you said , I questioned why the certainty expressed by you was based on paucity of explanation and wondered why the o/p faced with one form of dogma should replace the dealers view with another dogma .
Nothing you have said will assist the o/p in deciding which dogmatic opinion he should take on board , should be replace the dealers rhetoric for yours .
The purpose of my post was to show that demagnification exists in permanent magnets and anybody who wishes to catergorically state this does or does not have audible consequences really should have something better “than because i say so”
I don’t hold myself up to be an oracle on hifi matters , but if I did i would sure as hell make sure i knew what i was talking about and wouldn’t rely on rhetoric or pictures of my arse .
Gerald, none of your 'extended research' contradicts one word I wrote (unless you feel the OP's cartridge is likely to have been heated to over 220 degrees C). No doubt an off-shore wind turbine and a MC cartridge share many similarities, but to spare you further research I have found this simple guide that will answer most of your questions:
hahahaha
Daniel Quinn
Banned
Star Trekking across the universe
ynwoan is busy going nowhere cause he can't find reverse .
ynwoan is busy going nowhere cause he can't find reverse .
Barrymagrec
pfm Member
That is the first time I have ever heard of a cartridge having a 'magnet recharge' - obviously the rest of the industry is missing something here
I would imagine that if it was an EMT cartridge sent back to the factory for service they would simply run it through all the standard procedures as if it was a new one - and then to all intents and purposes it is. Whether it actually needed the procedure is immaterial. Possibly other manufacturers do the same but don`t itemise the procedure on the report.
Werner
pfm Member
That is the first time I have ever heard of a cartridge having a 'magnet recharge' - obviously the rest of the industry is missing something here
Allaerts does so, too.
But AFAIK Allaerts and EMT use Alnico, and Alnico is the most prone to demagnetisation of all magnet formulas. Not that this means that in real-life Alnico-based cartridges (and speakers) do deteriorate with significant amounts.
And yes, the charging of the (Alnico) magnet is part of the standard cartridge manufacturing process. That much I know.
Most cartridges do not use Alnico.
sq225917
Bit of this, bit of that
Gerald, I've owned three Linn carts over 20 years old, all of them measured to within a couple of percent of original specification for output voltage. One of them was a totally unused Karma, it measured no more closely to spec than the Troika that had been in constant use and retipped twice. I assume the slight difference between them and nominal spec was purely a result of production tolerances.
Linn do not offer remagnetization for any of their carts.
I would suggest that the OP asks the dealer in question by how much the output of the cart has dropped. He must already have the answer to hand- how else would he know it had dropped without measuring it?
You can hand wring as much as you like and obfuscate, but the simple truth in this instance is that it is far more likely the dealer is full of shit than that cart has been subjected to conditions that caused it to become demagnetized. Should the OP so desire I'd be happy to measure the cart for him and provide him with result for tracking, separation, FR and output voltage.
Linn do not offer remagnetization for any of their carts.
I would suggest that the OP asks the dealer in question by how much the output of the cart has dropped. He must already have the answer to hand- how else would he know it had dropped without measuring it?
You can hand wring as much as you like and obfuscate, but the simple truth in this instance is that it is far more likely the dealer is full of shit than that cart has been subjected to conditions that caused it to become demagnetized. Should the OP so desire I'd be happy to measure the cart for him and provide him with result for tracking, separation, FR and output voltage.
pure sound
Trade: manufacturer/distributor
The Io does although I can't say that I've ever encountered one that has lost output through age or abuse. But if a capable cartridge rebuilder offered to recharge the magnets as part of a rebuild I wouldn't say no. Its not uncommon for compression drivers using Alnico magnets to benefit from being recharged.
You are only looking at part of the requirement here.
It is crucial that the cantilever is stiff and light. The stiffness needs to be high in bending, and in most designs torsion too since the contact point of the stylus is not often on the neutral axis of the cantilever.
Boron is indeed stiffer than aluminium as a material, but since the stiffness of a beam is dependant on both the material and the geometry it is easy to make a thin walled aluminium tube stiffer in both bending and torsion than a boron rod of the same weight.
OTOH it is not as pretty looking, marketable or impressive sounding in the propaganda...
Sorry, this is one of the many common bits of hifi technical misinformation that pisses me off.
Daniel Quinn
Banned
Now your response is more than rhetoric which pleases me a lot , had the first five posts been so explanatory there would have been no need for my post .
I do however fear you have provided Linn with a marketing opportunity
Daniel Quinn
Banned
Tube's have their own issues .I would also contend a boron rod affords a better mounted end of the cantilever diamond .
Robert
Tapehead
Agreed, you might well end up with a stiffer cantilever but this needs balancing against the increased moving mass when you use boron, beryllium or gemstone.
Audio Technica recently used a tapered sapphire pipe - now that's interesting, and a christ knows how that was manufactured for them.
Cantilevers need to be 'stiff enough' and moving mass 'low enough' for the task.
Building them with a specification fit for other tasks is rather wasteful.
Yep, but for cantilevers in cartridges none I can think of, apart from a higher manufacturing cost, which makes it inferior to a rod which is less stiff despite the material.
You can cheaply make a thin walled ally tube as stiff and light a boron rod, as I wrote.
I am not advocating over engineering - quite the reverse, I never do!
There are loads of unnecessarily expensive bits used in hifi to justify high retail price. Exotic material rods as cantilevers is one of them IMO.
Gemstone and Beryllium I have not checked, though Beryllium is the only metal I know with a high specific stiffness (steel, ally, Magnesium and titanium have as near as dammit identical specific stiffnesses)
A tapered sapphire tube would be difficult to match with ally...