Introducing the Phono Cartridge Measurement Library

[morillon]

It is really necessary to observe at what level the tests are carried out...if they are at levels not too high the wear will be very reasonable( and very simple signals)..our concerns are often very correlated to these
(These are the torture test discs which are mechanically exposed to heavy wear...)

 

[Thomas_A]

It is really necessary to observe at what level the tests are carried out...if they are at levels not too high the wear will be very reasonable( and very simple signals)..our concerns are often very correlated to these
(These are the torture test discs which are mechanically exposed to heavy wear...)

Yes level is a factor. One can distinguish test records with or without torture tracks and records with music content. Another interesting question is whether embedded dirt is a factor. In that case it might at least in theory be possible to partly restore lost HF content by "deep cleaning".

 

[morillon]

I was just talking about the tracks used here for your fr measurements etc..on cbs100 or 1007..etc (what levels?)

 

[USER]

On this page I made some comparisons with Rays first experiment, repeated playing on same record for 480 hours, approx 1300 plays:

The Finish Line for your Phono Cartridge- Stylus Wear by Mike Bodell

Comparing the new vs worn cartridge on new record, you can see that the worn cartridge has slightly higher output (probably just cartridge to cartridge...

forums.stevehoffman.tv

Stylus (old vs. new) did not really differ, while record (old vs. new) had dropped ≈1-2 dB >10 kHz.

Interesting. And something that I will look out for so thank you.

It seems that your example shows a change starting below 10kHz at about 6-7kHz.

I also wonder if they removed the cartridge at any point and something like azimuth mis-adjustment came into play. The current stylus wear experiment measurements show the latter to the extreme and to the point that the results aren't helpful at all.

 

[Elkerton]

Years ago, and I am sorry I don’t have a reference, I remember Stanton conducting a test with an automatic turntable playing the same record 100 times continuously in a dust-free, controlled room. The scientists could determine no wear on the record.

 

[Thomas_A]

Interesting. And something that I will look out for so thank you.

It seems that your example shows a change starting below 10kHz at about 6-7kHz.

I also wonder if they removed the cartridge at any point and something like azimuth mis-adjustment came into play. The current stylus wear experiment measurements show the latter to the extreme and to the point that the results aren't helpful at all.

I think it was a T4P cartridge so no realignment possible/needed. If one accepts a linear wear; 2 dB drop at 1300 plays would equal 0.15 dB in 100 plays...

 

[dlaloum]

I'm surprised by the tail of the diamond that sticks out from the other side of the cantilever. And if there is a half-height micro-ridge diamond, then they probably usually install a full-height micro-ridge diamond. Or is it just mounted at half height?

Yes, I don't know the answer, and I assume that were the excess diamond sticking out the back removed, it would improve the effective tip mass substantially...

On the other hand, that is a very very "neat" job, pressure fitting the diamond into the cantilever, with perhaps a touch of glue at the rear to keep it in place

 

[dlaloum]

It is really necessary to observe at what level the tests are carried out...if they are at levels not too high the wear will be very reasonable( and very simple signals)..our concerns are often very correlated to these
(These are the torture test discs which are mechanically exposed to heavy wear...)

Yes, mistracking is a huge multiplier on wear - and higher levels on tracks are harder to track... so torture tracks often result in mistracking and therefore accelerated/multiplied wear... - so the levels of the record would be a critical factor.

It's all in the detail, isn't it!

 

[USER]

Another interesting question is whether embedded dirt is a factor. In that case it might at least in theory be possible to partly restore lost HF content by "deep cleaning".

This is a good question and to add to it I have certainly seen a dirty stylus lose HF response many times and quite obviously. I'd say that this situation is so common that it has likely affected quite a few measurements posted here, including my own.

Here is one recent example. I have seen worse but this is one of the few results I was smart enough to keep.

Before and after a quick brushing. The stylus had visible accumulated dirt/hair, likely from me leaving out the test record a few days out of laziness.

 

[Thomas_A]

This is a good question and to add to it I have certainly seen a dirty stylus lose HF response many times and quite obviously. I'd say that this situation is so common that it has likely affected quite a few measurements posted here, including my own.

Here is one recent example. I have seen worse but this is one of the few results I was smart enough to keep.
View attachment 323198
Before and after a quick brushing. The stylus had visible accumulated dirt/hair, likely from me leaving out the test record a few days out of laziness.

I can only guess, and given the composition of dust from the stylus that the stylus both acquire and leave dust particles continuously during play (i.e. according to the cleaning procedure manual consisting of about 12% jagged silica particles, 35% diamond dust, 40% miscellaneous particles, including soot, grit and particles worn from the record groove itself. The remaining 13% consisted of fibers and lint.).

My guess is that the finest modulations get the most of the fine dust particles for two reasons; the high frequency movement release particles from the stylus and secondly, the fine dust gets more easily packed in the finer grooves. I took some UV light pictures of grooves from an old LP and it seems the higher frequency modulated grooves shine up more than other grooves.

I plan some cleaning experiments with measurements and pictures...in a few weeks time.

 

[dlaloum]

Also worthy of consideration - with regards to wear and high frequencies.... long contact patch styli, will often read the vinyl surface above and below the wear track left by conical and elliptical styli...

So a worn record - worn primarily by conical and elliptical needles, will often play almost "like new" when played with a microline or similar needle... the longer the contact patch, the more pronounced the effect...

 

[Balle Clorin]

I see that is said often , but I still miss a visual/geometric confirmation that it the case . For that to work the contact area must ignore the damage , can it really do that? If all damages are like a hole in the road I understand that a wide tyre may ignore it, but are all damages like that?if the damage is a hump I cannot see how the stylus can ignore it..

 

[restorer-john]

Years ago, and I am sorry I don’t have a reference, I remember Stanton conducting a test with an automatic turntable playing the same record 100 times continuously in a dust-free, controlled room. The scientists could determine no wear on the record.

No doubt that was a Stanton ultra polished low-wear stylus they used for the 'test'...

 

[dlaloum]

I see that is said often , but I still miss a visual/geometric confirmation that it the case . For that to work the contact area must ignore the damage , can it really do that? If all damages are like a hole in the road I understand that a wide tyre may ignore it, but are all damages like that?if the damage is a hump I cannot see how the stylus can ignore it..

Standard wear is mostly (but not all) a worn path in the vinyl, I believe, but if the needle was mistracking and bouncing around, then there may be humps.... c'est la vie

 

[JP]

Shure did a paper that showed an embossing effect that caused a multi-dB level increase in their test. The problem is that nearly all of relative published material is from a time of simpler shapes and higher tracking forces.

 

[USER]

Audio-Technica AT-ML140/OCC
Click to increase size

Notes

• These are from @mackat
• The second set has FR adjusted to my CA-TRS-1007
• This cartridge is from the early 1990s and is part of the PCOCC wiring/coil craze of the time
  • From what I can tell the result is supposed to be lower inductance (here 380mH)
    • Only the top-tier AT-ML180 went down to 240mH
• Nude, microlinear stylus with aluminum cantilever
• Performs as expected from Audio-Technica
  • The only real question with their cartridges is which one out of about three FR curves will we get
  • They are a very consistent brand
    • Does the AT-ML150+ with beryllium cantilever perform differently?
• Despite test record limitations this looks like an excellent, classic Audio-Technica cartridge
  • Especially if loaded at around 100pF so that it is more neutral
  • Trackability (cantilever) may be what distinguishes this from the highest-end Audio-Technica cartridges

 

[USER]

Audio-Technica AT-E90
An appeal to the youth market
Or, the last days of disco
Click to increase size

Notes

• This is a rare, beryllium cantilever-based Audio-Technica cartridge
  • Hopefully a fun measurement set for enthusiasts and collectors
  • I was always curious about it as I like the odd and shiny look and that it is one of the cheapest beryllium cartridges to try out
• Low hours, nude, 0.2 x 0.7 elliptical stylus
  • There is a beautiful tapered finish on the cantilever
  • And a big fat diamond
• I was curious to see if the use of beryllium would result in a more flat FR
  • Clearly it does not --in fact this is in line with Audio-Technica's brightest cartridges
    • The marketing material reinforces this fact: "sparkling," "vivid," "bright" are the terms used to describe it
      • Remember that the CD format was still new when this cartridge was sold (1984-87)
        • (I believe CD got to 25% of US market share by 1987)
        • And I read this material as showing a medium directly competing with the new thing on the latter's terms
  • It would have been nice to see a flat, Shure-like result but clearly they stick to their house curves
    • Does the official measurement show a more controlled high frequency resonance?
      • As it's a chunky cartridge (like Ortofon 2Ms) could it be especially sensitive to VTA?
• Still not as cool as the AT-E32!!

 

[aaaakkkk]

• Does the AT-ML150+ with beryllium cantilever perform differently?

I don't have an AT-ML150, but I do have an AT-ML170

on the first measurement I tried to adjust my "Ortofon Test Record LP"

The second measurement is the uncorrected "Ortofon Test Record LP"

 

[Balle Clorin]

I see people say things like corrected response to TRS-1007. What is actually done then?. Is it an eq or mathematical manipulation ,and what is actually done with the original wav file?

 

[aaaakkkk]

I see people say things like corrected response to TRS-1007. What is actually done then?. Is it an eq or mathematical manipulation ,and what is actually done with the original wav file?

I tried, perhaps not entirely successfully.