Introducing the Phono Cartridge Measurement Library

[JP]

@narud this is a new 150MLX.

 

[narud]

@narud this is a new 150MLX.

im pretty sure i bought this as unused from someone. its been a while so im not completely sure. i havent put on any hours since i bought it.

 

[JP]

im pretty sure i bought this as unused from someone. its been a while so im not completely sure. i havent put on any hours since i bought it.

Figured it be easier for you to compare to a focus-stacked image than us try and decipher yours as I know how different the picture can be from what you see.

 

[USER]

This is the best photo I could get of an old NOS ATN150MLX. It's super hard to light reflections right on microlinear diamonds.

It was easier to see by playing with lightroom for a VN5MR.

 

[narud]

well, my mlx probably has very little to any use. it looks closer to the vm95ml i bought new and was able to look at under the scope before using it than my 33ptg which has 70ish hours.

 

[aaaakkkk]

View attachment 330486

i always have issues getting a decent pic with my super old iphone so theres some more flare here than what you see through the eye piece.

Doesn't look worn out.

 

[dlaloum]

Shure V15VX with Jico SAS/B stylus (pmount 110he version)
View attachment 330432
-Shure V15Vx body with sas stylus meant for a pmount 110he at 1.2 grams
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2

I got best results with this combo by dropping the R loading dramatically (27k to 35k) and raising the capacitance to 500pf+

There is a cantilever resonance between 14kHz and 16kHz (I have two samples of the SAS stylus, one has resonance at 14k the other at 16k...) - which is very different from the original V15V styli which had their resonance at 32kHz (!) - you have to use EQ to bring it back to the neutrality it should have, either via loading or via digital EQ.

As a result, I concluded a while back, that the SAS stylus design, probably mates better with the higher inductance bodies rather than the low inductance ones like the V15V ...

 

[aaaakkkk]

This doesn't look right. Distortion is very high above 6kHz. Is this completely worn out?

What numerical values and at what frequency should be in order to consider the stylus not worn out.
As I understand it, at 1 kHz it should be less than -30 dB.
How much should it be at 5kHz, 6kHz, 7kHz, 8kHz, 9kHz, 10kHz?

 

[USER]

That is impossible to say given the wide variety of diamond shapes, starting performance, set-up, etc. We can perhaps begin to answer for specific types once we have more examples posted with photographs. My best guesses are here and as always I welcome input for the guides. I think best practice is to take a "before" shot (measurement) and picture and follow up every hundred hours or so.

Edit: Taking another look, I am wondering if that rise is making the distortion look worse. No matter what, something is off. Maybe it's set up and something like an overhang issue or a combination of things.

 

[narud]

I got best results with this combo by dropping the R loading dramatically (27k to 35k) and raising the capacitance to 500pf+

There is a cantilever resonance between 14kHz and 16kHz (I have two samples of the SAS stylus, one has resonance at 14k the other at 16k...) - which is very different from the original V15V styli which had their resonance at 32kHz (!) - you have to use EQ to bring it back to the neutrality it should have, either via loading or via digital EQ.

As a result, I concluded a while back, that the SAS stylus design, probably mates better with the higher inductance bodies rather than the low inductance ones like the V15V ...

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.

 

[narud]

Audio Technica 150mlx (different stylus)

-this is the other stylus i have which looks pretty much the same under the scope as the first one. so, pretty close to unused. 1.5 grams
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2
-again, this mlx body doesnt have the lowest inductance generator.

 

[USER]

Audio Technica 150mlx (different stylus)
View attachment 330501
-this is the other stylus i have which looks pretty much the same under the scope as the first one. so, pretty close to unused. 1.5 grams
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2
-again, this mlx body doesnt have the lowest inductance generator.

That looks more or less right for the cartridge. This is an old measurement that needed further adjustment but the stylus broke so it is the best I can do. Yours is close, though your resonance goes a bit higher still since it is a CBS STR-100 result. Based upon my history with that cartridge a slight overhang refinement can tame it a bit more. I now use digital calipers to help place it on the headshell at manufacturer's recommendation. I got it expressly for this cartridge, lol. It's finicky.

That distortion is still there. It's off if the cartridge is new. Could it be the phono preamp?

 

[narud]

That looks more or less right for the cartridge. This is an old measurement that needed further adjustment but the stylus broke so it is the best I can do. Yours is close, though your resonance goes a bit higher still since it is a CBS STR-100 result. Based upon my history with that cartridge a slight overhang refinement can tame it a bit more. I now use digital calipers to help place it on the headshell at manufacturer's recommendation. I got it expressly for this cartridge, lol. It's finicky.

View attachment 330502View attachment 330503
That distortion is still there. It's off if the cartridge is new. Could it be the phono preamp?

i used the same pre for the v15vx/sas and at95ml measurements which dont show this level of distortion. on all of these carts, im just eyeballing it with the technics gauge. the mlx and 150ea carts are mounted on two individual headshells and have their overhang about as accurate as all the other carts ive measured. i guess i could break out the calipers and try and get it even closer?

 

[USER]

i used the same pre for the v15vx/sas and at95ml measurements which dont show this level of distortion. on all of these carts, im just eyeballing it with the technics gauge. the mlx and 150ea carts are mounted on two individual headshells and have their overhang about as accurate as all the other carts ive measured. i guess i could break out the calipers and try and get it even closer?

I highly recommend it. Eyeball doesn't cut it and it can cause confusion like how we are seeing right now. Here is an old one on a CBS STR-100 that is off similarly to yours. It's not properly set-up.

Here's how I adjust now. I was only comfortable starting this thread once I started using the calipers. My results are very consistent now. Not perfect, but the measurements often say why.

 

[aaaakkkk]

That is impossible to say given the wide variety of diamond shapes, starting performance, set-up, etc. We can perhaps begin to answer for specific types once we have more examples posted with photographs. My best guesses are here and as always I welcome input for the guides. I think best practice is to take a "before" shot (measurement) and picture and follow up every hundred hours or so.

Edit: Taking another look, I am wondering if that rise is making the distortion look worse. No matter what, something is off. Maybe it's set up and something like an overhang issue or a combination of things.

View attachment 330500

I have different distortion values on different recordings, any thoughts on these measurements?
Why such difference?

 

[narud]

Shure M97HE SAS/B stylus (from pmount m110he)

-Shure M97he body with sas/b at 1.2 grams.
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2

i do keep seeing that drop in the right channel highs, so maybe i will by another test record.

 

[USER]

Shure M97HE SAS/B stylus (from pmount m110he)
View attachment 330520
-Shure M97he body with sas/b at 1.2 grams.
-artdjpre modded to 0/100pf. switch is at 0pf. cables measure 120pf.
-technics sl-q2

i do keep seeing that drop in the right channel highs, so maybe i will by another test record.

Again, that looks like azimuth misadjustment to me. Classic case where one channel starts either above or below the other and then ends up the opposite. See if you can lower the left side of the cartridge (if you are facing it) just a tiny bit. Maybe with one of the plastic space rings that come with cartridges between it and the headshell where the screw goes. If you are lucky you can even simply rotate your headshell counter clockwise just a tiny little bit. Then check for changes and adjust as needed. I suggest you read the set-up tips on page one. They can only help.

 

[narud]

I highly recommend it. Eyeball doesn't cut it and it can cause confusion like how we are seeing right now. Here is an old one on a CBS STR-100 that is off similarly to yours. It's not properly set-up.

View attachment 330521

Here's how I adjust now. I was only comfortable starting this thread once I started using the calipers. My results are very consistent now. Not perfect, but the measurements often say why.

View attachment 330522

well, just double checked with digital calipers and im right at 52mm.

 

[mackat]

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.

 

[narud]

Again, that looks like azimuth misadjustment to me. Classic case where one channel starts either above or below the other and then ends up the opposite. See if you can lower the left side of the cartridge (if you are facing it) just a tiny bit. Maybe with one of the plastic space rings that come with cartridges between it and the headshell where the screw goes. If you are lucky you can even simply rotate your headshell counter clockwise just a tiny little bit. Then check for changes and adjust as needed. I suggest you read the set-up tips on page one. They can only help.

just tried rotating the m97 clockwise and re ran it and it didnt really make a difference. if it really is azimuth, it would take a pretty major change because there was a decent amount of play in the socket.
edit- after looking at it again, the rotated measurement did get the channels tighter up to the peak, but it didnt fix the early drop off in the right channel