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ZYX cartridges

GT

You say:
“WHAT EVER YOU DO NOT UNDER ANY CIRCUMSTANCES PUT A MAGNET THAT CLOSE TO THE CARTRIDGE…”

Please read the quote below that I have already given at the end of post #54.

‘I have been using the following vdH suggestion from Q. 31 for years:

“…Since phono cartridges always tend to collect potentially damaging magnetic stray particles over time, another suggestion is to mount a magnet on your record player near to the cartridge’s REST position (capitals mine) (of course not against it), such that this magnet functions as a magnetic vacuum cleaner - catching magnetic stray particles away instead of having them ending up inside your expensive cartridge…”

I use a flat, small fridge magnet left permanently under the arm rest.’


This Q.31 quote is what Dr. vdH suggests.

I can’t now recall how long I have been using this tip, but it is I think, upwards of ten years. There have been no detrimental effects on any of my cartridges.

Your WARNING appears to have resulted from a misreading. Neither I, nor Dr. vdH, are suggesting that the magnet goes on to the platter, or anywhere other than 'near' the arm rest when not playing a record.

To make it clear, at the end of a record session, or at any other time the arm goes onto the arm rest, the cartiridge is stationed above the magnet until playing resumes.

The magnet, under the cartridge, is separated from it by whatever the distance may be between the underside of the cartridge and the magnet. Obviously if there is insufficient clearance between the floor of the plinth under the armrest and the underside of the cartridge when on the arm rest this tip should not be followed.

Your point about steel and iron platters appears to be not to the point. There is no inconsistency in Dr. vdH’s views here. If not under the arm rest, then where is it, precisely, that you say that Dr. vdH is suggesting that the magnet be placed?
 
eguth said:
GT

You say:
“WHAT EVER YOU DO NOT UNDER ANY CIRCUMSTANCES PUT A MAGNET THAT CLOSE TO THE CARTRIDGE…”

Please read the quote below that I have already given at the end of post #54.

‘I have been using the following vdH suggestion from Q. 31 for years:

“…Since phono cartridges always tend to collect potentially damaging magnetic stray particles over time, another suggestion is to mount a magnet on your record player near to the cartridge’s REST position (capitals mine) (of course not against it), such that this magnet functions as a magnetic vacuum cleaner - catching magnetic stray particles away instead of having them ending up inside your expensive cartridge…”

I use a flat, small fridge magnet left permanently under the arm rest.’


This Q.31 quote is what Dr. vdH suggests.

I can’t now recall how long I have been using this tip, but it is I think, upwards of ten years. There have been no detrimental effects on any of my cartridges.

Your WARNING appears to have resulted from a misreading. Neither I, nor Dr. vdH, are suggesting that the magnet goes on to the platter, or anywhere other than 'near' the arm rest when not playing a record.

To make it clear, at the end of a record session, or at any other time the arm goes onto the arm rest, the arm is put on the arm rest until playing resumes.

The magnet is then under the cartridge, separated by whatever the distance may be between the underside of the cartridge and the magnet. Obviously if there is insufficient clearance between the floor of the plinth under the armrest and the underside of the cartridge when on the arm rest this tip should not be followed.

Your point about steel and iron platters appears to be not to the point. There is no inconsistency in Dr. vdH’s views here. If not under the arm rest, then where is it, precisely, that you say that Dr. vdH is suggesting that the magnet be placed?
Click to expand...

To avoid confusion - how far (in centimeter's) is the gap between the magnet and your cartridge?
 
badger 748

I accept this question as relevant and helpful. I have no computer at home, and am using the university one at present.

I will measure the gap in cm and get back to you in due course.
 
badger 748

I have now measured the distance from the top of the magnet to the bottom of the cartridge. It is about 28mm.
 
Cheers - I am no expert, but that does seem awfully close to something that also has a magnet.
Unless the manufacturer of my cartridges advised this was 100% safe to do, I would not put a magnet 28mm away from my cartridge.
Interesting thread this.
 
badger 748

It does not seem awfully close to me. Before I first tried the tip I remember that I took two (2) fridge magnets and tried various distances between them to try to ascertain interaction. I assume that the fridge magnets are more powerful than the magnet in my cartridge.

As you no doubt know, Dr. vdH is not only a physicist but also a manufacturer and modifier of cartridges, with decades of experience and an international reputation.

This tip has been on his website for many years. I presume that he uses it on his own turntable and no doubt there are hundreds- perhaps thousands- of readers of his website that also use it. By now if there were any undesirable effects of doing so he would have removed the suggestion.

The magnets in cartridges are not all the same, some more powerful than others. There is always the option of using a smaller or less powerful magnet under the cartridge than a fridge magnet, to err on the side of caution.

As far as the distance in my setup is concerned my arm rest is, probably, higher from the armboard than many others. If you are interested in trying the tip you could take it up with the manufacturer of your cartridge or Dr. vdH himself. As a matter of interest, what cartridge do you use?
 
I see your point if it's a vdH cartridge and AJ himself says this is ok to do - you have it str8 from the horses mouth so to speak.
My main cart day-to-day is an Ortofon A90.
Maybe I will ping an email to Ortofon or their representative to see what they say about doing this and a safe distance?
Cheers
 
eguth said:
badger 748

I have now measured the distance from the top of the magnet to the bottom of the cartridge. It is about 28mm.
Click to expand...

Just as I thought. Do you realise what you are recommending here?

I suggest, seeing as you attend a University you visit the library and read up on magnetism...
 
Fridge magnets are about as weak as you can get and volume for volume will be nowhere near the strength of those inside a cartridge, they only work so well because there's several metres of them on every fridge door.

Personally I'd prefer to occasionally waft a smaller, stronger and very carefully secured Neodymium magnet under my cartridge than I would to leave anything vaguely magnetic near it unsupervised for periods of time.

Of course this all begs the questions, what the hell are you doing in your music room, mass producing iron filings?
 
All the advice I've ever read or heard has advised against allowing a magnet anywhere near a MC or MM cartridge.

Where are all the iron debris coming from anyway ?
 
GT
Please do not put words into my mouth. I am just following the suggestion made by Dr. vdH. ‘ Reading up on magnetism’ will not assist Dr. vdH: he knew enough about it before making his tip public. Your argument is with Dr. vdH, not with me. Your view is that 15cm needs to be the gap distance. Dr. vdH has not specified any minimum. He has just indicated that the magnet should be "near to the cartridge’s rest position (of course not against it)".

Purite Audio
You may doubt my word for it, but if you go to the vdH website you will see that he does recommend this. After you get to the home page search DIY. Then go to phono FAQ. You will find his tip at “31Q,” final paragraph. I trust that this assists. GT made the mistake of assuming that vdH did not recommend this,before he checked his facts: "... I can assure you he would not recommend anything like this..." (GT).

Hi Fi Dave
There is often unanimity on advice, but not always. Even if Dr. vdH had been the only one in the world that agrees with his suggestion that does not make it wrong without more.

In answer to your question “Where are all the iron debris coming from, anyway? “ please note what Dr. vdH says:

“…Since phono cartridges always tend to collect potentiallydamaging magnetic stray particles over time…”

Such stray particles might come from different sources in different environments. No doubt there are such particles and that they get into cartridges and this is why, ESCO, for example, always clean the magnetic material when retipping.
 
Just out of curiosity. I sometimes see A.J VanDenHul described as 'Doctor' and sometimes 'Professor'. But Vdh himself seems to use no such description, mentioning only that he attended the university at Delft, where he 'studied'. So is the man himself unduly modest, or are other people getting it wrong?
I can find no reference from accessible files at Delft to Vdh being awarded a Doctorate, or holding a Professorship .But that could be poor research on my part or partial records. Given that the academic titles are used (by others) to bolster Vdh's reputation, it would be reassuring to know the facts.....especialy as A.J seems to make no real academic claims, and seems altogether more modest. Before making cartridges he was quoted in an early 'Stereophile' article as a journalist. Of course you can be a journalist, an academic and a maker of world-class cartridges......but a bit of clarity would do no harm (I've owned both his cartridges and his cables..in fact I still use his cables).
 
paskinn said:
Just out of curiosity. I sometimes see A.J VanDenHul described as 'Doctor' and sometimes 'Professor'. But Vdh himself seems to use no such description, mentioning only that he attended the university at Delft, where he 'studied'. So is the man himself unduly modest, or are other people getting it wrong?
I can find no reference from accessible files at Delft to Vdh being awarded a Doctorate, or holding a Professorship .But that could be poor research on my part or partial records. Given that the academic titles are used (by others) to bolster Vdh's reputation, it would be reassuring to know the facts.....especialy as A.J seems to make no real academic claims, and seems altogether more modest. Before making cartridges he was quoted in an early 'Stereophile' article as a journalist. Of course you can be a journalist, an academic and a maker of world-class cartridges......but a bit of clarity would do no harm (I've owned both his cartridges and his cables..in fact I still use his cables).
Click to expand...

About Aalt Jouk Born in 1937. Sudied at T.U. Delft. Worked several years on a proton accelerator. Have been involved in teaching (Physics, Chemistry, Optics & Communication technology) for 13 years, also worked as technical journalist for 13 years. My company specialized in metal & non-metal conductors. Latest activity further specialisation and business in Aramid, Basalt, Carbon and Dyneema Fibres and Weaves. Hobby indoor: Building phono-cartridges. Hobby outdoor: Cycling with sons. Biggest commitment: Top quality sound reproduction in the finest details
 
Let us assume that the magnetic field from cartridge ‘x’ extends 15cm (i.e. a G.T. ‘worst case’ scenario).

Assume, also, that to avoid any interaction with (or demagnetisation of) the cartridge magnet, we place a fridge magnet on the arm board near the arm pivot, 15.1 cm away from the cartridge.

What benefit will result from the use of the fridge magnet? It will attract magnetic debris from an area within its field, but that field only extends to short of the cartridge magnet- on the assumption that the fridge magnet is weaker than the cartridge magnet.

If this is correct then the cartridge magnet is free to attract debris despite the fridge magnet's hoard- save, perhaps, to some extent, at the field's overlap.
 
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