Fun with vinyl measurements

[Thomas_A]

Did you do anything to load the cartridge? The V15 has a bit of inductance; in parallel with the capacitance of the tonearm cable and the input capacitance of your phono section (not specified; it always should be in measurements like this). That results in a resonance that will behave like a treble tone control. If you didn't deal with this aspect, your results here are meaningless as they do not represent the actual cartridge performance.

For more on this see http://www.hagtech.com/loading.html

I have the Muffsy Phono preamp so I've been doing all sorts of loading tests in the past. I reduced R from 47k to 36k here:

Introducing the Phono Cartridge Measurement Library

This was our reference in the 1970s in a recording studio. We had an historic archive of concert performances cut to disc before tape. Our reference arms were the SAE 3000? large diameter disc curved on a large mass large diameter 16"? mains synced platter. At home at the time, I had a V15-IV on...

www.audiosciencereview.com

The original V15VxMR has a bit of drop in the highs - not linear as the original V15V-MR; the SAS/B usually a peak between 10-20 kHz given the same conditions. Not all stylii are identical though so each one needs some loading fine-tuning to be at their best.

 

[Icewater_7]

Did you do anything to load the cartridge? The V15 has a bit of inductance; in parallel with the capacitance of the tonearm cable and the input capacitance of your phono section (not specified; it always should be in measurements like this). That results in a resonance that will behave like a treble tone control. If you didn't deal with this aspect, your results here are meaningless as they do not represent the actual cartridge performance.

For more on this see http://www.hagtech.com/loading.html

Hi Ralph, Jim Jasmin here. We knew each other in MN via the Audio Society and several informal audiophile friend associations. I still keep in touch with Gene Lyle. Thanks for that link, and I hope your business is still thriving.

 

[atmasphere]

I have the Muffsy Phono preamp so I've been doing all sorts of loading tests in the past. I reduced R from 47k to 36k here:

Introducing the Phono Cartridge Measurement Library

This was our reference in the 1970s in a recording studio. We had an historic archive of concert performances cut to disc before tape. Our reference arms were the SAE 3000? large diameter disc curved on a large mass large diameter 16"? mains synced platter. At home at the time, I had a V15-IV on...

www.audiosciencereview.com

The original V15VxMR has a bit of drop in the highs - not linear as the original V15V-MR; the SAS/B usually a peak between 10-20 kHz given the same conditions. Not all stylii are identical though so each one needs some loading fine-tuning to be at their best.

Loading might actually consist of a capacitor and resistor network.

Back 30 years ago I used to use Grado cartridges which seemed to be a bit bright in the highs- I loaded them at about 10K which took care of it. But these days I think that might have been a bad idea since that would require that the cartridge do 5x more work and that would have affected the stiffness of the cantilever, making it less able to trace the highs. This phenomena is quite measurable and its easily shown to be a mechanical thing rather than electrical. I can point you to measurements of that if you wish.

So I remain skeptical at this point that the peak you measured is indicative of the cartridge itself.

Hi @Icewater_7 ! Say hi to Gene for me.

 

[JP]

This phenomena is quite measurable and its easily shown to be a mechanical thing rather than electrical.

Would love to see this evidence.

 

[Icewater_7]

Loading might actually consist of a capacitor and resistor network.

Back 30 years ago I used to use Grado cartridges which seemed to be a bit bright in the highs- I loaded them at about 10K which took care of it. But these days I think that might have been a bad idea since that would require that the cartridge do 5x more work and that would have affected the stiffness of the cantilever, making it less able to trace the highs. This phenomena is quite measurable and its easily shown to be a mechanical thing rather than electrical. I can point you to measurements of that if you wish.

So I remain skeptical at this point that the peak you measured is indicative of the cartridge itself.

Hi @Icewater_7 ! Say hi to Gene for me.

OK, I will pass on your salutations to Gene. Back in the day I thought it would be great for both you and audiophiles to put your direct-drive tube amps into a full production environment. All the best to you!

 

[Thomas_A]

Loading might actually consist of a capacitor and resistor network.

Back 30 years ago I used to use Grado cartridges which seemed to be a bit bright in the highs- I loaded them at about 10K which took care of it. But these days I think that might have been a bad idea since that would require that the cartridge do 5x more work and that would have affected the stiffness of the cantilever, making it less able to trace the highs. This phenomena is quite measurable and its easily shown to be a mechanical thing rather than electrical. I can point you to measurements of that if you wish.

So I remain skeptical at this point that the peak you measured is indicative of the cartridge itself.

Hi @Icewater_7 ! Say hi to Gene for me.

Yes, loading is that, but not sure what you want to say? I've tried many capacitance values, between 140-800 pF and different R. These are around on this site as well.

Looking at different stylii I have three JICO SAS/B (+ the one measured that I sent back above, peaking at 10 kHz) and one JICO SAS/Z. Here are some more measurements with different stylii:

JICO SAS/B I

JICO SAS/B II:

JICO SAS/B III:

JICO SAS/B IV:

JICO SAS/Z:

 

[Thomas_A]

Some more optimisation.

Crosstalk vs VTF and azimuth

Sweep Ortofon 47 kOhm:

Swep 36 + 47 kOhm (L + R):

 

[atmasphere]

Would love to see this evidence.

From the Steve Hoffman site where for me it got more interesting. In this case we see what happens when the cartridge is loaded. This one is a LOMC. But a page or two later I put up some meausrements showing that the coil inductance was so low it could pass squarewaves at 10KHz quite well. So we know a lot of the effects of loading LOMC cartridges has to do with a mechanical reaction to the cantilever getting stiffer due to the extra work it has to do.

This is true of any alternator, including high output cartridges where the inductance is much higher. Its so high though that they can also ring. where a LOMC cartridge will not.
You might want to look at this cartridge loading calculator where you can see the phenomena of unloaded high output cartridges having a high frequency peak.

 

[Icewater_7]

From the Steve Hoffman site where for me it got more interesting. In this case we see what happens when the cartridge is loaded. This one is a LOMC. But a page or two later I put up some meausrements showing that the coil inductance was so low it could pass squarewaves at 10KHz quite well. So we know a lot of the effects of loading LOMC cartridges has to do with a mechanical reaction to the cantilever getting stiffer due to the extra work it has to do.

This is true of any alternator, including high output cartridges where the inductance is much higher. Its so high though that they can also ring. where a LOMC cartridge will not.
You might want to look at this cartridge loading calculator where you can see the phenomena of unloaded high output cartridges having a high frequency peak.

My HOMC cartridge signaling is wired balanced from the very short pigtail coming out of my linear tracking arm through no more than a meter of this Mogami wire: https://www.designacable.com/mogami-2549-22awg-balanced-cable-shielded-hi-end-mic-xlr-trs-wire.html. My fully balanced phono pre sits right underneath to accept the XLR cabling. I’m sure I could see what effects different loading might have per that technical article you cited but I have just accepted the loading effects as-is and am only focusing now on the mechanical cartridge alignment parameters like azimuth and VTA. This setup has been working very well for me for more than 10 years.

 

[atmasphere]

My HOMC cartridge signaling is wired balanced from the very short pigtail coming out of my linear tracking arm through no more than a meter of this Mogami wire: https://www.designacable.com/mogami-2549-22awg-balanced-cable-shielded-hi-end-mic-xlr-trs-wire.html. My fully balanced phono pre sits right underneath to accept the XLR cabling. I’m sure I could see what effects different loading might have per that technical article you cited but I have just accepted the loading effects as-is and am only focusing now on the mechanical cartridge alignment parameters like azimuth and VTA. This setup has been working very well for me for more than 10 years.

I've been running a balanced cartridge connection since 1989 (our MP-1 preamp was one of the very first balanced line preamps made). Definitely the way to go!

I don't think you can do any measurements that will really show what the cartridge is doing if its improperly loaded. To be clear I'm talking about a high output cartridge, since LOMC cartridges act considerably different owing to the lower inductance and higher Q of the windings.

 

[Icewater_7]

I've been running a balanced cartridge connection since 1989 (our MP-1 preamp was one of the very first balanced line preamps made). Definitely the way to go!

I don't think you can do any measurements that will really show what the cartridge is doing if its improperly loaded. To be clear I'm talking about a high output cartridge, since LOMC cartridges act considerably different owing to the lower inductance and higher Q of the windings.

I know it has been a decent amount of time elapsed to remember exactly, but my consciousness is telling me that you were one of the earliest designers to see the inherent advantages of a balanced signal path from input to output. Must have been both so much fun and highly satisfying to develop products that worked so well for music reproduction. Hard to imagine a job better than that. I had one of my own “lifetime best jobs” designing professional audio equipment at Digidesign/Avid Technology (15 year stint). We get up in the morning and are eager to get to work every day. I still feel lucky right now that we decided to move to CA and all of the subsequent outcomes from that, mostly great.

 

[JP]

From the Steve Hoffman site where for me it got more interesting. In this case we see what happens when the cartridge is loaded. This one is a LOMC. But a page or two later I put up some meausrements showing that the coil inductance was so low it could pass squarewaves at 10KHz quite well. So we know a lot of the effects of loading LOMC cartridges has to do with a mechanical reaction to the cantilever getting stiffer due to the extra work it has to do.

This is true of any alternator, including high output cartridges where the inductance is much higher. Its so high though that they can also ring. where a LOMC cartridge will not.
You might want to look at this cartridge loading calculator where you can see the phenomena of unloaded high output cartridges having a high frequency peak.

That’s not evidence for what your claimed. My own tests posted in that thread for anyone to try show no audible difference when the load on the test cart (5R5 DCR) is 1R, after level matching of course.

 

[atmasphere]

That’s not evidence for what your claimed. My own tests posted in that thread for anyone to try show no audible difference when the load on the test cart (5R5 DCR) is 1R, after level matching of course.

Actually, it is. You can see clearly that loading the cartridge affected the squarewave response. Yet you can also see that when a squarewave is passed through the cartridge winding, it emerges on the other side perfectly intact.

This shows that loading the cartridge is making the cantilever stiffer, less able to (measurably) trace high frequencies.

Are we talking about two different things?

 

[JP]

Actually, it is. You can see clearly that loading the cartridge affected the squarewave response. Yet you can also see that when a squarewave is passed through the cartridge winding, it emerges on the other side perfectly intact.

This shows that loading the cartridge is making the cantilever stiffer, less able to (measurably) trace high frequencies.

Are we talking about two different things?

It appears that you’re not looking at all the evidence that was provided in that thread as it relates to the effect on the audio signal. No measurable differences in FR, no one has been able to differentiate the different loads in ABX, and the effect on the square wave was very small and well above audible. The latter could be more of an affect on the phonostage than the cartridge.

 

[Balle Clorin]

Test record Denon XL-7004
I put my AT-OC9MLii back on, and also tried a VTA adjustment. I lifted the SME V 2.5mm at the pillar(+0.6 degree) and then removed the mat for an additional -2mm on the platter. I got no change and no improvement on the Tacet IMD:
But some other test records shows improvements, on crosstalk and IMD. Photo after 2.5mm adjustment mat still in place

 

[Thomas_A]

View attachment 359827View attachment 359828View attachment 359829View attachment 359830
Test record Denon XL-7004
I put my AT-OC9MLii back on, and also tried a VTA adjustment. I lifted the SME V 2.5mm at the pillar(+0.6 degree) and then removed the mat for an additional -2mm on the platter. I got no change and no improvement on the Tacet IMD:
But some other test records shows improvements, on crosstalk and IMD. Photo after 2.5mm adjustment mat still in placeView attachment 359831

Not sure if I am reading this correctly but if you are raising the tonarm at the base your get higher VTA/SRA. A better stylus fit (SRA) in the groove can elevate the signal level, especially at high frequencies (but should be negligible at 1 kHz). Not sure about the mechanism of azimuth re VRA/SRA on azimuth, but I see two basic mechanisms for azimuth.

1. The angle of movement of magnet/coils vs. motor, which should be +/-45° (i.e. with groove walls). This changes the relative level between channels and is phase related as well.
2. The position of the magnet or coils relative motor, which is dependent on VTF and antiskate force. This changes the overall level in both channels.

Also see Yosh pages regarding arm height changes. I does have an effect on VTF as well.

VTA

 

[Balle Clorin]

some trigometry to get to SRA, need an second attempt photo to eliminate "parallax" error. but I think the method is good

I get tilt angle of 70.8 while Obrey spec is 70 +-3. Adding Tilt angle to cantilever angle with record gives SRA. Hard to get photo lighting to give a photo to measure SRA directly. Need to correct for vinyl thickness vs cd=1.2mm

 

[atmasphere]

It appears that you’re not looking at all the evidence that was provided in that thread as it relates to the effect on the audio signal. No measurable differences in FR, no one has been able to differentiate the different loads in ABX, and the effect on the square wave was very small and well above audible. The latter could be more of an affect on the phonostage than the cartridge.

I guess I don't get what you're talking about. If you look at the waveforms at the post to which I linked, you can see that the member Ampexed did indeed measure differences in FR (as shown by the change in squarewave response).

 

[JP]

I guess I don't get what you're talking about. If you look at the waveforms at the post to which I linked, you can see that the member Ampexed did indeed measure differences in FR (as shown by the change in squarewave response).

And his measurements weren’t replicable. Granted, I went through a bit more exhaustive of a process, ensuring the waveforms being compared were indexed, which is usually where people get bit on this stuff, along with not considering run variation.

 

[Thomas_A]

The new JICO SAS/B stylus sound really fine. These things are like jewelry, with variations of quality.