How much weight is enough to damage vinyl?

[dlaloum]

I just picked up a JVC 4MD-10X Shibata - VTF 2g.... my first high(ish) VTF line contact..... rather looking forward to listening to it.

[flavio81]

Just FYI, Panasonic's semiconductor cartridges [for CD4 records] have Shibata styli, the mid compliance version is specified for 1.5-2.5g and the low compliance version (460C) is specified for 3.0-4.0g VTF.

[electrokid]

I just picked up a JVC 4MD-10X Shibata - VTF 2g.... my first high(ish) VTF line contact..... rather looking forward to listening to it.

Well that makes me feel a little less lonely

I've been running a 4MD-10X since the 1970s and I can honestly say I've never heard it put a foot wrong. I didn't fit the extra weight that comes with the kit but I did have to add a little extra weight to the headshell - couple of grams or so. When fitted new I was just running a stereo system and I could use the DT33 range of styli but it's more difficult these days to find a DT33 stylus that is properly defined - I've seen eBay items where it's stated "DT33 = DT33HSE" and a plain DT33 advertised as a direct replacement for 4DT-10X which of course it's not. Now I'm running quad it's noticeable that the 30KHz pilot is consistently received even with an old DT33 stylus. The frequency response of the cartridge is quoted as being flat between 10Hz and 60KHz - all the tests I've ever done with it (mainly in the 70s with the 2ch system) suggests that is the case.

There are some styli available on eBay from Canada at the moment...

http://www.ebay.co.uk/itm/140675290886?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

And while I'm here - has anyone tried - or have an opinion on these headshell dampers...

http://www.ebay.co.uk/itm/190504434570?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[dlaloum]

Yes I had him make up a calibrated set of the dampers in 1mm through to 4mm thicknesses - I needed shimms - and these do a very good job.

Was there an audible difference - yes, marginal. - did I measure it - no. (unusual for me )

Was the difference due to VTA and additional mass, or due to some form of damping effect.... who knows?

They are beautifully made, high quality - and if you check his website he has a range of different shapes (some are wider than others, and will not fit in all headshells) - also you can request (as I did) specific thicknesses and he will oblige. - highly recommended.

The DT33 styli (for MD1016 cartridge) are identical to the 4MD-10x styli with the exception of the shibata tip - so a "DT33 Shibata" is effectively a 4MD-10x stylus. - They are interesting as being one of the rare examples of high(er) VTF line contact - as well as having a good rep as a nice sounding cartridge!

bye for now
David

[electrokid]

Was the difference due to VTA and additional mass, or due to some form of damping effect.... who knows?

When I was setting up I thought it was the additional mass - after adding mass I re-adjusted tracking weight to 1.5 grams - I was aiming to get it to track properly at that weight. The arm is the SME 3009 Series 2 improved with removeable (recessed logo) headshell.

DT33 Shibata" is effectively a 4MD-10x stylus

Agreed - finding one is another matter

[Ldg]

This JVC 4MD-10X stuff is off topic chaps, suggest start a new thread or use PM ?

On topic, I wonder why line contact styli are seldom paired with high VTF suspensions ? It would seem the obvious thing to do, to make the best of line contact tracing geometry.

Obviously, line contact styli become blades, in the limit as minor radius becomes smaller and smaller. That is quite possibly why there are imperical minima as to stylus minor radius. ie there is a practical limit of perhaps 4um which manufacturers do not exceed.

To put it another way, below a certain minor radius, a stylus damages or wears the record groove excessively. Otherwise, all styli would be true line profile as standard by now.

Then it's reasonable to infer that record wear/damage increases as minor radius decreases, for a set VTF and major radius? And perhaps this is a clue as to why line contact profile styli are not often paired with higher VTF suspensions?

In practice, increased wear/damage from decreased minor radius might be mitigated by increased major radius. It's commonly believed that line contact profile has increased surface area contact. However, this does not stand scrutiny, as posted previously on other threads. It would require groove indentation to be significantly higher for line contact types, which contradicts other beliefs held to be true, and the laws of physics to boot !

So, I venture that line contact styli profiles are compromises. In practice, by selecting specific minor and major radii, a manufacturer can devise a profile which offers similar or tolerably adverse groove wear, relative to a biradiall or spherical. If 'tolerably adverse' is chosen, then line contact styli might need to be paired with lower VTF suspensions to attain overall similar record wear to biradial/spherical styli.

This is a candidate explanation for a) why in practice line contact profile styli have no significant difference in record wear and b) why they are generally paired up with lower VTF suspensions.

If so, it's all very clever spin to present line contact tips as a 'low wear' profile. When, by principle and common sense, it's perhaps quite the opposite and has to be compensated or compromised to match other types !

[dlaloum]

Try this:
http://www.ebay.com.au/itm/NEEDLE-STYLU ... 613wt_1185

The MD1016 / 4MD-10x also went by several other names!

[Ldg]

That's blatently off topic, DL, and you could have PM'ed. Intentional ? Read the rules.

[flavio81]

On topic, I wonder why line contact styli are seldom paired with high VTF suspensions ? It would seem the obvious thing to do, to make the best of line contact tracing geometry.

Obviously, line contact styli become blades, in the limit as minor radius becomes smaller and smaller.

Obviously? ld, is that you or someone has stolen your account?
How about the major radius? Do you prefer to be pricked with 100g of vertical force with a sharp pin or with a wide, sharp blade? Which one would you choose?

Also, i think you focus way too much on groove indentation. You can get the same indentation depth, but distribution of the pressure that achieves said distribution is not necessary the same. The contact radius on a Shibata, compared to a similar elliptical is blatantly bigger, for God's sake!! Again, on the "pin vs blade" example, the indentation on your skin can be similar too.

I've already shown an example of high VTF Shibata tips. That most line contact tips are paired with low/mid VTF designs is just a reflection of current market trends, not engineering choices. Audiophiles have lost all traces of manliness and are scared by any VTF over 2.0 gram. Audiophile magazines, manufacturers of cartridges and record care products have a long record of jumping on the "vinyl wear" bandwagon to sell all kinds of ridiculous stuff such as Stylast, record preservatives, Laser turntables and the like.

[dlaloum]

Historical Fencing techniques against bladed weapons include grabbing the cutting edge .... which is much less dangerous than the wee point of a 18th century smallsword.... a thrust from which was quite capable of penetrating very thick leather jackets (ie most armor short of plate) - I'm with flavio on this... the point is more dangerous than the blade. (oops I thought for a second I was on the fencing forum)

[Ldg]

Obviously, line contact styli become blades, in the limit as minor radius becomes smaller and smaller.

Obviously? ld, is that you or someone has stolen your account?
How about the major radius? Do you prefer to be pricked with 100g of vertical force with a sharp pin or with a wide, sharp blade? Which one would you choose?

Yes, it's me
And, I still think this one appeals to common sense.

It's quite possibly why there is a practical lower limit as to minor radius. More to the point (!), a large major radius is required to mitigate the effect of a smaller minor radius. So whether I'd prefer to be pricked with a spherical profile or a line contact profile....neither....my point is they appear to be devised to be about the same 'sharpness'.

But, since there is traceability advantage to smaller minor radii, a manufacturer might prefer a balance toward more wear/damage to take as much geometric advantage as possible. And then mitigate by pairing with a lower VTF suspension. So that's why few line contact tips are paired with higher VTF suspensions, i venture.

Again, on the "pin vs blade" example, the indentation on your skin can be similar too.

Precisely. It seems to be arranged that way, for line contact versus spherical/biradial too.

Audiophiles have lost all traces of manliness and are scared by any VTF over 2.0 gram.

Yes this factor cannot be ignored ! But if wear is adverse, and if one is into conspiracy theories, this would have been manipulated by the industry to to get line contact tips accepted for CD4 et seq

It's always good to see line contact styli in a suspension capable of higher VTF, IMO. It seems a fair endorsement that vinyl wear is generally very low. As I see it, wear is generally very low, irrespective of tip type. It's arranged to be that way, but that doesn't happen naturally though.

Historical Fencing techniques against bladed weapons include grabbing the cutting edge ....

That was the Django Reinhardt school of fencing ?

[v1nn1e]

The point is that we don't drop our stylii straight down onto the musical part of the record groove. The effect is more one of dragging a blade at right angles across the surface, so much more benign anyway, IMHO.

[Ldg]

The blade's not always at right angles, it varies with the signal. So it's more like shaving, where the blade makes an angle of up to 30 deg (depends on the signal). Sharper blades potential cut/scrape rather than glide. Even at right angles though, potential to scrape increases with sharpness. As I see it.

[missan]

The blade's not always at right angles, it varies with the signal. So it's more like shaving, where the blade makes an angle of up to 30 deg (depends on the signal). Sharper blades potential cut/scrape rather than glide. Even at right angles though, potential to scrape increases with sharpness. As I see it.

One question is if the indentation is deep enough to do some scraping? Another thing is where do the mtrls go? I use a rather high force with my Shibatas, without really knowing, it seems fine.
missan