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Introducing the Phono Cartridge Measurement Library

Here are some recent measurements I did with 2 different 150MLX styli, a 150MLX body, and a 740ML body. I tried to adjust things reasonably well, but there may have been some azimuth/alignment inconsistencies.

Stylus #1 was purchased new from Thakker, Stylus #2 was purchased second-hand as NOS (I don't think I've gotten them mixed up).

Capacitance could be greater than ~100 pF in actuality; I don't believe I measured the tonearm/headshell wiring.


View attachment 330525View attachment 330526View attachment 330527View attachment 330528
What's up with #2? You don't have to worry about not telling them apart with measurements so that's good. Your first one also looks just like the old one I posted. At least the inconsistencies are consistent, lol. I may have that measurement so I'll update this if I can make a direct comparison.

Edit: This is pretty funny. The difference seems to be capacitance. As I know mine had an overhang issue (among other things, likely), I'd bet yours did too. Probably off by the same amount too. These measurements are wild.

Audio-Technica AT150MLX COMPARISON.png

Here are the results from two different measurement sessions where eyeball set-up led to bad results. All with same 120pF load. In total these seem to cover the outlier results we are seeing. You can follow my frustrations with the cartridge on the MM MC MI thread as I was open about it and posted a lot of these results. The worst ones had too little overhang, so less than the required 35mm for my headshell.
Denon Overhang.jpg

Audio-Technica AT150MLX Eyeball Set-up Inconsistency.png
Audio-Technica AT150MLX Eyeball Set-up Inconsistency (120pF).png
 
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What's up with #2? You don't have to worry about not telling them apart with measurements so that's good. Your first one also looks just like the old one I posted. At least the inconsistencies are consistent, lol. I may have that measurement so I'll update this if I can make a direct comparison.
Lol, that is true.

I'm not sure what's up with it!
 
Audio Technica at150sa
150sa.png

471CC338-1094-4A07-94BF-0ACE4EC45BEE.JPG

Audio Technica at150sa
-shibata diamond on tapered aluminum cantilever at 1.5 grams
-this one has some heavy use. before i picked up the sek-2, i sent it out to joe long for evaluation and this is his pic.
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2
 
Audio Technica at150sa
View attachment 330541
View attachment 330542

Audio Technica at150sa
-shibata diamond on tapered aluminum cantilever at 1.5 grams
-this one has some heavy use. before i picked up the sek-2, i sent it out to joe long for evaluation and this is his pic.
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2
It might be good to check what the effective capacitance is at "0" with artdjpre....maybe.... ;-)
 
Just an example of Azimuth impact when pushing SME headshell in opposite directions. No detectable play in connector
1701364242074.png

Poor mans wally Fulcrum.Adjusting Azimuth by a plastic slice and adjusting tightness of L or R screw
1701364824247.png
 
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It might be good to check what the effective capacitance is at "0" with artdjpre....maybe.... ;-)
testing the pre for the actual capacitance of the circuit is above my pay grade. however, heres what i can do. i know the puffin was tested here as being 50pf. my signet measurement posted earlier was done on the puffin. heres a comparison of the left channel files of the signet. one measurement from the puffin and the other from the artdjpre on the 0pf setting with the slq2 which has the higher capacitance cables (120pf) than the sl1700mk2 (80pf) that i use with the puffin. so, theoretically 120pf vs 130pf.

filenorm set to 0
am50 both pres left.png

filenorm set to 1
am 50 both pres norm1.png
 
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are you thinking of the v15v body? this is the x. at only a couple 2db's of high end rise, its pretty similar to the at33ptg. i know the sas on the v15vmr body has a much greater high end rise.
The V15V and V15VMR are identical bodies, the V15VxMR is different... (from memory)
 
The V15V and V15VMR are identical bodies, the V15VxMR is different... (from memory)
i know that. i should have been more clear. this measurement is the v15vx body which has higher inductance than the v15v and doesnt have the laminated cores. its electrically the same as the vstiii and v15-rs.
 
i know that. i should have been more clear. this measurement is the v15vx body which has higher inductance than the v15v and doesnt have the laminated cores. its electrically the same as the vstiii and v15-rs.
Ahh OK - I have not directly measured the V15Vx (as I don't own one)... I could run some modelling to estimate what the ideal EQ might be... I have done some work with the M97x... (and matching SAS) - so I have some estimates for a higher inductance body, and for a lower inductance body - but not for that in between one!

I'll check my M97x EQ/Loading settings and post them later
 
Audio Technica 150mlx stylus- Metal body mount vs plastic (distortion experiment)

MLX stylus-150mlx body vs 150ea body (both metal)
mlx stylus on mlx and ea body.png

MLX stylus- 150mlx body vs signet am50 body (metal vs plastic mount)
mlx stylus on mlx and signet body.png

-these are all left channel readings of my newest 150mlx stylus
-all of these were recorded using a technics sl-q2 with an art djpre on the 0pf setting
-the first graph is a 150mlx vs 150ea body. both have heavy metal mounting caps. the 150ea has lower inductance and resistance than the mlx body. the high end rise is different with the lower inductance body having a greater rise. however, both bodies look to have roughly matching 2nd harmonic distortion.
-the second graph is the 150mlx body vs a signet am50 body. the signet has the lighter plastic mounting cap. in this case, the mlx has lower inductance and resistance compared to the signet body which leads to an expected difference in the high end rise. however, this time the distortion doesnt match. the plastic bodied signet shows lower 2nd harmonic distortion than the mlx using the same stylus.
-could the heavy metal mounting cap not be playing well with the technics arm and leading to higher distortion? id be open to any ideas or theories.
 
Audio Technica 150mlx stylus- Metal body mount vs plastic (distortion experiment)

MLX stylus-150mlx body vs 150ea body (both metal)
View attachment 330788
MLX stylus- 150mlx body vs signet am50 body (metal vs plastic mount)
View attachment 330789
-these are all left channel readings of my newest 150mlx stylus
-all of these were recorded using a technics sl-q2 with an art djpre on the 0pf setting
-the first graph is a 150mlx vs 150ea body. both have heavy metal mounting caps. the 150ea has lower inductance and resistance than the mlx body. the high end rise is different with the lower inductance body having a greater rise. however, both bodies look to have roughly matching 2nd harmonic distortion.
-the second graph is the 150mlx body vs a signet am50 body. the signet has the lighter plastic mounting cap. in this case, the mlx has lower inductance and resistance compared to the signet body which leads to an expected difference in the high end rise. however, this time the distortion doesnt match. the plastic bodied signet shows lower 2nd harmonic distortion than the mlx using the same stylus.
-could the heavy metal mounting cap not be playing well with the technics arm and leading to higher distortion? id be open to any ideas or theories.
Have you measured the arm/stylus resonance? understanding where it sits (what frequency) and how substantial the bump is (a matter of how substantial the damping in the stylus suspension is) will help to see whether there is an arm matching issue - you need to record frequencies between 5Hz and 20Hz...
 
Audio Technica 150mlx stylus- Metal body mount vs plastic (distortion experiment)

MLX stylus-150mlx body vs 150ea body (both metal)
View attachment 330788
MLX stylus- 150mlx body vs signet am50 body (metal vs plastic mount)
View attachment 330789
-these are all left channel readings of my newest 150mlx stylus
-all of these were recorded using a technics sl-q2 with an art djpre on the 0pf setting
-the first graph is a 150mlx vs 150ea body. both have heavy metal mounting caps. the 150ea has lower inductance and resistance than the mlx body. the high end rise is different with the lower inductance body having a greater rise. however, both bodies look to have roughly matching 2nd harmonic distortion.
-the second graph is the 150mlx body vs a signet am50 body. the signet has the lighter plastic mounting cap. in this case, the mlx has lower inductance and resistance compared to the signet body which leads to an expected difference in the high end rise. however, this time the distortion doesnt match. the plastic bodied signet shows lower 2nd harmonic distortion than the mlx using the same stylus.
-could the heavy metal mounting cap not be playing well with the technics arm and leading to higher distortion? id be open to any ideas or theories.
Having become familiar with the internal design of cartridges, disassembled and examined under a microscope, I have come to the conclusion that all cartridges are different.
It is simply impossible to make them the same, even if you test 10 pieces of 740 and 10 pieces of 540, they will all have a spread of parameters, and it’s not a fact that 740 will be better than 540.
The design of the cartridge body itself is such that the coils are wound with a very large number of turns of wire.
The core in each of these coils is bent differently. The coils with the cores themselves are mounted in the housings, also at different angles. As a result, the magnets that should be located exactly between the core are located differently in each cartridge, hence the spread of parameters.
Your insert has a 150MLX which has a strong rise. Most likely the string is tensioned weaker than that of a similar insert. changing string tension, for a normally configured insert, can reduce the resonant peak by about 2-3 dB.
 
ive accepted that this particular stylus is bright. what i was curious about was why the 2nd harmonic distortion in the high end is higher on the measurements with the two metal capped generators when compared to the plastic bodied signet generator. while i tested the mlx stylus in the 150mlx and 150ea bodies i should probably check it in the 150sa body as well to see if the trend holds. i wish i had some other plastic capped generators.
 
Having become familiar with the internal design of cartridges, disassembled and examined under a microscope, I have come to the conclusion that all cartridges are different.
It is simply impossible to make them the same, even if you test 10 pieces of 740 and 10 pieces of 540, they will all have a spread of parameters, and it’s not a fact that 740 will be better than 540.
The design of the cartridge body itself is such that the coils are wound with a very large number of turns of wire.
The core in each of these coils is bent differently. The coils with the cores themselves are mounted in the housings, also at different angles. As a result, the magnets that should be located exactly between the core are located differently in each cartridge, hence the spread of parameters.
Your insert has a 150MLX which has a strong rise. Most likely the string is tensioned weaker than that of a similar insert. changing string tension, for a normally configured insert, can reduce the resonant peak by about 2-3 dB.

I have to say that I very much disagree with this sentiment. In fact this thread was started on the belief in the consistency of companies such as Audio-Technica. See the measurement proof of concept post here for examples: https://audiosciencereview.com/foru...tridge-measurement-library.46108/post-1643773

Certainly there can issues like channel inductance differences. (At least that what I think you are getting at, not sure if the string tension you are bringing up is directly connected, excuse me if I missed your main point.) In fact I tried blaming my bad results with the AT150MLX on just that. Again, this cartridge seems to drive people crazy, lol. See this post:


But JP showed that overall that cartridge was quite consistent. He measured 6 of these:


We are simply not seeing this issue much in the near 100 measurements posted so far. I measure this for every cartridge and mention it if it could be an issue (see Grace cartridge). But I am starting to believe that some eras/manufacturers were worse than others. I have a NOS Technics coming up in a few weeks that is showing an anomoly and I expect it to look similar to JPs' cartridges of that era, which have showed disappointing results. But they are old cartridges and that's a part of the game.

To me there is a big issue with that stylus whether people choose to believe it or not. The measurements are not lying. The fact that there are also more normal results with other styli seems to say that this is not a tonearm compatibility issue. This was a used stylus --pre-owned NOS, but was it really??-- , so thinking the manufacturer is at fault before anything else would not be my first thought. That resonance should be very audible. Perhaps that's why it was sold. Maybe it's a retip gone bad, who knows? More global pictures including the cantilever could help.

i was curious about was why the 2nd harmonic distortion in the high end is higher on the measurements with the two metal capped generators when compared to the plastic bodied signet generator.

What I see is well within a reasonable margin of error. It could simply be set-up. You'd need more samples to know for sure that there is a difference.
 
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I have to say that I very much disagree with this sentiment. In fact this thread was started on the belief in the consistency of companies such as Audio-Technica. See the measurement proof of concept post here for examples: https://audiosciencereview.com/foru...tridge-measurement-library.46108/post-1643773

Certainly there can issues like channel inductance differences. (At least that what I think you are getting at, not sure if the string tension you are bringing up is directly connected, excuse me if I missed your main point.) In fact I tried blaming my bad results with the AT150MLX on just that. Again, this cartridge seems to drive people crazy, lol. See this post:


But JP showed that overall that cartridge was quite consistent. He measured 6 of these:


We are simply not seeing this issue much in the near 100 measurements posted so far. I measure this for every cartridge and mention it if it could be an issue (see Grace cartridge). But I am starting to believe that some eras/manufacturers were worse than others. I have a NOS Technics coming up in a few weeks that is showing an anomoly and I expect it to look similar to JPs' cartridges of that era, which have showed disappointing results. But they are old cartridges and that's a part of the game.

To me there is a big issue with that stylus whether people choose to believe it or not. The measurements are not lying. The fact that there are also more normal results with other styli seems to say that this is not a tonearm compatibility issue. This was a used stylus --pre-owned NOS, but was it really??-- , so thinking the manufacturer is at fault before anything else would not be my first thought. That resonance should be very audible. Perhaps that's why it was sold. Maybe it's a retip gone bad, who knows? More global pictures including the cantilever could help.



What I see is well within a reasonable margin of error. It could simply be set-up. You'd need more samples to know for sure that there is a difference.
ive looked at it at all angles under the sek-2 and it looks like every other mlx stylus. no way its a retip and the diamond looks very close to unused. my at33ptg with 70 something hours looks more "worn" ,if you want to call it that, than this mlx. my mlx body has an inductance of 413/414mh. the last one i most recently sold also had its inductance in the 400 range. the 150ea and 150sa bodies measure where they are supposed to per spec so its not the meter. i had two other mlx's years ago as well. i wish i would have had a meter back then but they were all super bright as well. ill try measuring this stylus on the sa body and see if the distortion stays at the same level.
 
Having become familiar with the internal design of cartridges, disassembled and examined under a microscope, I have come to the conclusion that all cartridges are different.
It is simply impossible to make them the same, even if you test 10 pieces of 740 and 10 pieces of 540, they will all have a spread of parameters, and it’s not a fact that 740 will be better than 540.
The design of the cartridge body itself is such that the coils are wound with a very large number of turns of wire.
The core in each of these coils is bent differently. The coils with the cores themselves are mounted in the housings, also at different angles. As a result, the magnets that should be located exactly between the core are located differently in each cartridge, hence the spread of parameters.
Your insert has a 150MLX which has a strong rise. Most likely the string is tensioned weaker than that of a similar insert. changing string tension, for a normally configured insert, can reduce the resonant peak by about 2-3 dB.
I picked up a couple of batches of old cartridge bodies from repair shops that were shutting down (years ago!) - this allowed me to measure a number of "identical" cartridges and cherry pick the best of them...

Within certain ranges (eg: Shure, Audio-Technica) - there were also different bodies with different resistance/inductance parameters, that share the same stylus mounting, which then allows for further tuning of the response, through the selection of a body to best match an aftermarket stylus....

For those with a keen interest in MM cartridges, it is worthwhile keeping an eye out for bulk lots of used cartridges...
 
ive accepted that this particular stylus is bright. what i was curious about was why the 2nd harmonic distortion in the high end is higher on the measurements with the two metal capped generators when compared to the plastic bodied signet generator. while i tested the mlx stylus in the 150mlx and 150ea bodies i should probably check it in the 150sa body as well to see if the trend holds. i wish i had some other plastic capped generators.
Another thing to consider, might be how well/tightly the stylus fits to the body... if it is a loose fit, there may be some body resonance creeping in. (I doubt that would cause 2nd harmonic though.... can't see why that is happening....)
 
Another thing to consider, might be how well/tightly the stylus fits to the body... if it is a loose fit, there may be some body resonance creeping in. (I doubt that would cause 2nd harmonic though.... can't see why that is happening....)
Funny you should mention this. For reference, this is a measurement of a loose cartridge body-stylus connection. I bought them separately and I had to return the body. Stylus is NOS. The Signet body is very similar to the AT150 (styli are compatible) though it has around 550mH inductance.

I may be the only person that gets excited when something goes wrong.

Signet TK7Ea - Denon DP-30L II - CBS¹ᶜ - 2.png
Signet TK7Ea - Denon DP-30L II - CBS¹ᶜ - 3-2.png
 
Funny you should mention this. For reference, this is a measurement of a loose cartridge body-stylus connection. I bought them separately and I had to return the body. Stylus is NOS. The Signet body is very similar to the AT150 (styli are compatible) though it has around 550mH inductance.

I may be the only person that gets excited when something goes wrong.

View attachment 331059View attachment 331060
I have a few signet bodies - including a very nice p-mount that fits the AT150/440 family styli
I just consider them "part of the family"... (which they are!)
 
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