Introducing the Phono Cartridge Measurement Library

[Thomas_A]

However, it is worth noting that the frequency response measurement method mentioned here does not take into account the usually very high amplitude of unwanted resonance in the range up to 20Hz.
Which is always added to the signal.
Please look at the above graphs, the signal peak at 1 kHz is about - 63 dB, and the peak amplitude of unwanted resonance is about - 54 dB

What we get is signal in the range of 20 Hz- 20 kHz, bonus, unwanted bonus, a high amplitude signal in the range up to 20 Hz.

Measure distortiion on the 300 Hz +15 dB tracks with and without damping with RTA REW.

 

[Quando]

Measure distortiion on the 300 Hz +15 dB tracks with and without damping with RTA REW.

I am not currently using a turntable with resonance damping so I cannot measure it.

 

[Thomas_A]

I think that many Ortofon SPUs will have a problem reproducing a signal with an amplitude of +15 dB/300 Hz, and certainly with a signal of +18db/300 Hz.
I also think that many DJ cartridges will not have a problem with such a signal, or even a greater +18 dB/300 Hz.

Does this mean that a DJ cartridge for $100 is better than a $1500 SPU?

Even within the physical x-max of a given cartridge the distortion increase with level. So reducing the unwanted resonance also contriubute to lower distortion. In addition you get lower scrubbing flutter. This gives lower noise as well.

Neither of these factors affect frequuency response which is related to cartridge and/or loading and RIAA spec.

 

[Quando]

Neither of these factors affect frequuency response which is related to cartridge and/or loading and RIAA spec.

This measurement also shows the second and third harmonics, and crosstalk, so it measures not only the response but also the distortion.

While crosstalk is quite clearly shown on the graph, the second and third harmonics, which could tell how the cartridge handles reproducing the entire band, are represented in a way that is not very clear, making it difficult to compare.

I don't know if I'm thinking correctly?

 

[Quando]

Temperature

 

[Thomas_A]

This measurement also shows the second and third harmonics, and crosstalk, so it measures not only the response but also the distortion.

While crosstalk is quite clearly shown on the graph, the second and third harmonics, which could tell how the cartridge handles reproducing the entire band, are represented in a way that is not very clear, making it difficult to compare.

I don't know if I'm thinking correctly?

Generally correct. Though sweeps are made at rather low levels and music peaks 20 dB or more above reference level, so a more demanding signal would be better to sort out the LF resonance effects on distortion. It is also of interest to look at higher order distortion components. As I showed in another thread one can also look at the flutter around 4-20 Hz where resonance often peaks.

 

[JP]

However, it is worth noting that the frequency response measurement method mentioned here does not take into account the usually very high amplitude of unwanted resonance in the range up to 20Hz.
Which is always added to the signal.

You need to do some basic research/experimentation on how frequencies sum. If the low fres is wide enough to affect above 20Hz, then it'll show in the plot. This is why we sometimes see differences around 20Hz for similar carts on different arms. It's not going to affect above that outside of potential tracking issues; were that true, the tone of the singer would change every time the bass drum hits. Things just don't work that way.

The sum of these two signals gives a true picture of what we get from the phono cartridge.
The measurement of the cartridge response using the method presented here is only part of the picture of what we get.
Am I thinking correctly?

If an arm has bad resonance in the audible range, that will alter the response in that range. However, that's an issue of that arm or system (arm + cartridge) and not just the cartridge, so why would we include it in a cartridge measurement? Fortunately the vast majority of arms perform Good Enough so this entire tangent is rather moot.

because what would be the point of producing turntables, arms, for tens of thousands of dollars if the cartridge frequency response remained the same?

Extract money from gullible people, or, to a far lesser extent, cater to people who like to own audio jewelry.

While crosstalk is quite clearly shown on the graph, the second and third harmonics, which could tell how the cartridge handles reproducing the entire band, are represented in a way that is not very clear, making it difficult to compare.

The harmonic amplitude is plotted at the fundamental frequency, i.e. 2H plotted at 1kHz is 2kHz, etc.

 

[mglobe]

View attachment 397781

Temperature View attachment 397780

I don’t think many people play records at 0 or 40 C. Reality is that there’s likely little more than 2-3degc variation for most people.

 

[Quando]

Extract money from gullible people, or, to a far lesser extent, cater to people who like to own audio jewelry.

 

[Quando]

Your measurement shows how the cartridge will respond in the 20Hz-20kHz range. That's OK.
Your measurement does not show what the signal will be in the range up to 20Hz
The signal we get from the cartridge is the sum, the signal in the 20Hz - 20kHz range + the signal up to 20Hz.
These are inseparable
The amplitude of the signal (sometimes very large in the range up to 20Hz) depends on many variables, including the system for suppressing unwanted resonance that the manufacturer has used in the cartridge.

 

[USER]

Can we please move this conversation to an appropriate thread? This is muddying up this one in almost every sense. Any of the vinyl measurements ones will do.

 

[Quando]

I don’t think many people play records at 0 or 40 C. Reality is that there’s likely little more than 2-3degc variation for most people.

In winter, the temperature in my house is about 20 degrees Celsius, but on very hot days, the temperature reaches 30 degrees. The truth is, at such high temperatures, I don't listen to vinyl records

 

[Balle Clorin]

Can we please move this conversation to an appropriate thread? This is muddying up this one in almost every sense. Any of the vinyl measurements ones will do.

Yes, take the discussion here
Post in thread 'Fun with vinyl measurements'

Fun with vinyl measurements

I see now that my writing was not clearly. I had 2 pots to adjust. To make 2 voltages/sinus on the scope to X volt. Both interacts on the result, so I adjusted a tiny amount on one and then the other, alternating. If I tried to correct one sinus curve/voltage fully , and then the other, I...

www.audiosciencereview.com

 

[redflag]

Was really excited to find this thread and spent a weekend reading through the results. What a breath or fresh air to actually have objective and quantitative methods applied to analog audio! I got back into vinyl about five years ago and have been gradually improving my system since then, but there is so much dubious and outright bad information out there progress has been blundering.

It's really cool to see how consistent the results are between different users with completely different set ups. The data consistency is much better than I would have expected going into such a project. It's also gratifying to see the results are more or less in line with my subjective experience, it gives me previously lacking confidence that my ears and judgement aren't completely off-base.

I especially appreciate how these tests have informed capacitance loading on MM cartridges, something that I was having trouble A/B testing on my own setup.

I hope I can add some useful contributions of my own to the library. I own several early Stanton MM cartridges. A few Stanton 500 mk I, at least one 500 mk II, and a Stanton 600, along with a stockpile of OEM styluses for the 500, at least one being sealed NOS. While the 500 is not the 680, it was the broadcast standard in the US for decades. It is not hard to find on eBay and NOS styli for the 500 can still be found for reasonable prices here and there. So all that said I think it would be a good one to add to the library. I also have some other entry-level pickups I pulled off vintage turntables but those would be more curiosities and the styli I have are unlikely to be in great shape. I also have a newish VM540ML and a couple AT95E I could throw on the already large pile of measurements for these pickups as well.

Regarding the chart generation script, it looks like this has been really well done and is in great hands. If there is ever a need for an extra hand there I have some undergraduate research experience doing data visualization and frequency-domain audio processing in Python, and several years of experience in backend Python development in general. Doesn't seem this is at all necessary, but seemed relevant and thought I should al least mention it.

I'm going to try to get up to speed on the actual testing methodology here. Sorry if my questions have already been answered or this is the wrong thread, I did read the whole thread to this point but I'm sure there is some stuff I missed!

Audio-Technica AT71E vs AT95E
View attachment 314726
This might be my favorite graph so far.

Same output, same resistance, same inductance. Pretty sure they are basically the same cartridge inside. Two entirely different turntables though and on different days!

You can see the effects of cartridge-tonearm incompatibility clearly. The AT95E was measured on a Sony PS-X50 with a high-mass tonearm that yields optimal results. Unfortunately the AT71E did not fit on its headshell so it is on a low-mass tonearm. Also note that the latter is close to a 40 year old cartridge and the former is likely around 10 years old. It's always a bit shocking seeing how well cartridges can hold up through time when well-made and cared for. Audio-Technica can do this in its sleep. It's also even more shocking to see such a match on two completly different (DD) turntables.

If you think this is crazy, in a few days I will post an even wilder one. Another two Audio-Technica cartridges. Made by different people and, obviously, through entirely different systems. Different CBS records. Should mention different capacitance settings too. (Guess what the FR will be.) Made years apart.

Very interested in this chart. I'm trying to get a handle on tonearm resonance and how it would potentially impact my own setup, given that my main turntable (Thorens TD-2001) is one that has a tonearm that is a bit on the higher-mass side (TP-90, listed as 17g EM).

I want to make sure that I understand what this chart is showing. Am I correct in my understanding that this is a FR chart of the AT71E on a Sony PS-X50? What is the chart that I am supposed to be comparing it to? What is the difference you are highlighting there? Thanks!

 

[USER]

Very interested in this chart. I'm trying to get a handle on tonearm resonance and how it would potentially impact my own setup, given that my main turntable (Thorens TD-2001) is one that has a tonearm that is a bit on the higher-mass side (TP-90, listed as 17g EM).

I want to make sure that I understand what this chart is showing. Am I correct in my understanding that this is a FR chart of the AT71E on a Sony PS-X50? What is the chart that I am supposed to be comparing it to? What is the difference you are highlighting there? Thanks!

Welcome! I appreciate that you went out of your way to create an account here in order to engage.

The AT95E measurement was taken on the high-mass Sony PS-X50, which is good as the recommended tracking force is 2g. The AT71E could not fit on its headshell and so it was taken on a Denon DP-35F, which has a low-mass servo tonearm. I probably should have played around with the electronic dampening system but it was set to the recommended setting matching the recommended tracking force of 1.75g.

So I don't think it will be an apples to apples comparison to your situation if I am reading you correctly and you are discussing using a high-mass tonearm with a cartridge that is of a higher dynamic compliance. Do note that the bigger issue of using a turntable with a high-mass tonearm with a high compliance cartridge is that the cantilever may not be able to handle the weight for long. The compliance is related to the springy-ness of the cantilever in a super simplified view. The risk is damaging the cantilever and suspension more so than having issues with the FR. This is why I am not going to go out of my way to conduct experiments and measure the effects. Then of course most cartridges made today are medium and low compliance as low-mass tonearms are more and more rare each day. The specs given can make it hard to say what the compliance really is, however, as multiple standards are used, so generalizing is not a bad thing. I'm really talking about something like a Shure V15 V-MR or a lot of the vintage classic cartridges. Definitely keep those FAR AWAY from a high-mass tonearm.

I'm sure others can offer more detailed advice or correct me if I got something wrong. This is a good calculator but you may have to convert the compliance (not easy to do funny enough) if it is a Japanese cartridge.

https://www.vinylengine.com/cartridge_resonance_evaluator.php

These are the original measurements for the cartridges. I hope they help.

Introducing the Phono Cartridge Measurement Library

If you do try cleaning the cantilever with 99% alcohol Well , 96% is the highest % that is possible to achieve with conventional distillation. Maybe I should re-tip it?

audiosciencereview.com

Introducing the Phono Cartridge Measurement Library

If you do try cleaning the cantilever with 99% alcohol Well , 96% is the highest % that is possible to achieve with conventional distillation. Maybe I should re-tip it?

audiosciencereview.com

 

[Quando]

This is the final measurement, I will not measure this cartridge again. Please remember that this is a copy with a new cantilever (a cantilever from a Pioneer PN-Q1 needle was used)
Technics SL-1200GR2 turntable (orginal headshell)
Needle pressure: 2.5 grams
Anti-skating: 3 grams
SUT: Ortofon T-30 (12 Ohm)
NAD 1155: Phono MM (100pf)
Capacitance of cables to Ortofon T-30: 140 pF
Capacitance of cables from Ortofon T-30 to NAD 1155: 40 pF
Sound card: Focusrite Clarett+ 2Pre USB
WAV: 16 bit-96kHz
Temperature: 16 degrees Celsius

 

[USER]

Oh good. You fixed your issue. It was obvious something was off. If you are planning on (re-)posting these in a more official manner and want me to add them to the index please follow the measurement post guidelines.

Introducing the Phono Cartridge Measurement Library

Skip to the index. After years of development we are finally launching our phono cartridge measurement library. These measurements were created using the brilliant cartridge response python script written by @scott wurcer and @JP. Information about its origins can be found in the following...

audiosciencereview.com

Edit: Thank you and added to the modification section of the index.

 

[Jimi Floyd]

@Quando this thread is meant to be a reference one which people can rely to if they want to be sure about frequency response, crosstalk and distortion of cartridges. You have been occupying the last pages with a lot of provisional, tentative graphs and outside references reporting whatever came out of your experiments, including hard to be believed performances from reputed brands. I have no authority here but anyway I feel compelled to recommend you to do your experiments at home and publish here NOT your intermediate results but ONLY the few FINAL plots you can swear are free from the errors which anybody does in the first period of his learning curve. Also, as @USER said, there is a format for the information supplied here that must be respected. Thank you for understanding, if you do.

 

[morillon]

in mc tours values of capacitance

I decided to check out another turntable cartridge that I received today. It looks like this:

Technics SL-1200GR2 turntable (orginal headshell)
Needle pressure: 2.5 grams
Anti-skating: 3 grams
SUT: Ortofon T-30 (12 Ohm)
NAD 1155: Phono MM (100pf)
Capacitance of cables to Ortofon T-30: 140 pF
Capacitance of cables from Ortofon T-30 to NAD 1155: 40 pF
Sound card: Focusrite Clarett+ 2Pre USB
WAV: 16 bit-96kHz

View attachment 398157

on the kuntrapuk the most logical would be the 6 ohm position..and the capacitance values are no longer of much interest
your value of crosstalk is probably anormal (the indicated antiskating value doesn't really make sense...)
etc

 

[JP]

The rising response from 1kHz is very odd, especially to see the exact some characteristic across two different cartridges. I suspect something is wrong and wouldn’t trust these measurements.