Let's Talk About VTF (Vertical Tracking Force)

It is also very important to use a scale that is close to record height. I use a river stone https://www.amazon.com/Riverstone-Audio-Record-Level-Turntable-Resolution/dp/B076DFZDS4

I have a unipivot and not adjusting the VTA for record thickness will change the VTF. I guess if you don't want to change it for every record thickness set it at the upper end for 180g or 200g if you have many. This way when you play a thinner record the VTF will be lower. The reverse would put you over specs.

I'm not sure if this is only unipivots.

 

I have been fiddling with it a lot. The range of my cart (Studiotracker) is 1.8-2.2, with 2.00 being recommended, but the sweet spot really is at 2.1 with a big difference already at 2.05. Didn't think it would make much of a difference but it sure did...

 

Actually, VTA (and SRA) has much to do with VTF since it will change as a direct result of the tracking force. The cantilever is pretty short from pivot to stylus, so small changes in VTF can lead to rather significant changes in VTA, and many believe that is the main change we hear when the tracking force is adjusted. The cartridge is designed with a specified VTA (in most cases) that is likely achieved at close to the specified nominal tracking force...

 

I don't like getting into discussions about stuff like this...I usually stay out because there are so many different opinions. But we can all learn a little more from those who know about this stuff documented in books. I hate white papers, but when it comes to cartridge's, which are very little things that cost lots of money, you want to preserve it for as long as possible....I've seen to many horror stories about a cart losing life because of stupidity or lack of knowledge. So let me add here. @Davey is correct about the relationship between Vertical Tracking Angle, Stylus Rack Angle as well as Vertical Tracking Force. One affects the other. What we don't realize is we can damage something in the inside of these carts very easily, you may not know it and then your cart has lost life way before its time...things in there are very delicate indeed. So when we set the VTF, we are setting the down force of the stylus in the record grooves...loading the suspension system as well as lining up the coils to the yoke. So this determines the tracking ability and aligns the coils to magnetic field of the magnet, this all adds to the linearity of the cartridge. That's why I believe its very important to shoot for the recommended setting by the manufacturer without going back and forth to much with the VTA or the VTF. So its really the suspension system of the cartridge that's really important. You can still achieve great sound by running it in, setting the proper force and leaving it alone until/if it gets out of wack. I wouldn't keep fiddling and peddling with things s so delicate. You don't want it too stiff or too light. The manufacturers set the recommended for a reason.

 

Some great and detailed posts above.
One point to clarify: I don't think anyone is advocating for going beyond the recommended range. My own 'umble fiddling is currently fixed well within those parameters, as explained in the original post.

As you were.

 

How do you measure the rake angle?

 

which is why I posted how important it is to scale at record height especially if you are at the high end. Or you won't know for sure what your tracking.

USB microscope, takes some effort.

 

I wasn't implying changing one wouldn't affect the other. Only that one is about an angle and the other has to do with weight; 2 very different things.

 

EXCELLENT diagram. I bookmarked it. Thanks !!!!

 

In my case I use a London Reference cartridge which has no cantilever; the stylus is basically just attached to the end of a short pole which is in turn attached to an electrically sensitive interface that responds to the movement of the stylus -- a process the company calls "positive scanning". Thus the VTF adjustments have no effect on VTA and SRA and vice-versa.

The recommended VTF for my cartridge is from 1.5 grams to 2.0 grams, and lately when experimenting with it I've found the lower the VTF the better the sound. I believe this is due to excellent stability of the medium-mass, oil-damped unipivot Immedia RPM2 tonearm I use it on. I am now listening with the lowest recommended setting: 1.5 grams. It might be my imagination but at even lower VTFs than 1.5 grams it sounds even better! But still I don't go below 1.5 grams, just in case.

 

That method could lead to some serious record wear... he should really be making sure it's between the recommended minimum and maximum.

 

I have a low mass arm 9.5g effective weight, close to lower end of medium mass on my NAD C558 with an Ortofon Super OM 30 with head shell weight intact, 5g total). I found through much trial and error that VTF of 1.45/1.46 (measured at record height w/mat using Riverstone gauge) worked best. I also had to lower my VTA just a little so that its only very slightly tail down. These 2 adjustments made a tremendous improvement and I feel quite set. Oh the Anti-skate I set to 1.5g. It seems now to play with zero IGD, when the anti-skate was less I did hear a little distortion in the inner grooves on the right channel.

My point is that I prefer the VTF below the recommended 1.5G, not far below yes, I think it might be due to tonearm mass/weight relation? I am wondering why this particular aspect is not talked about more often, or maybe I missed it?

Charles

 

Consider the cantilever suspension of a cartridge. It is a rubber donut that the cantilever passes through.

The recommended tracking force deforms the rubber to a "neutral, center" position, where the coils or magnets are placed in the center gap of the linear response of the magnetic motor. With non-ideal tracking weight, not only is the transducer placed outside of the center of the motor, where response can become non-linear on musical peaks, but also, the squished rubber suspension no longer deforms linearly - it resists motion more in one direction. Both sources of waveform distortion (among countless others in disc reproduction).

Too little tracking force, and the stylus tip will literally lose contact with high-acceleration grooves that drop out from under it. Too much, and besides the suspension fatigue, the vinyl deforms even more under the pressure, the elasticity of which is the source of mechanical resonance.

So a strong case can be made for using the recommendation.

Audio-Technica ART1000 - with the coils out at the cantilever tip, and black rubber suspension:

 

Really. I have seen an elliptical stylus literally shred a record due to too high stylus force.

 

I would love to hear any London cartridge. Positive scanning has advantages. The closest I have to a London is my two GE VR-1000's.

 

Very likely if it contributes to arm stability. My tonearm base sits immersed in a bath of oil, which really helps reduce the minute vibrations coming from the stylus/cartridge as the record plays, which I theorize is also part of the reason it works well at such a low VTF. I am wary though of playing it at lower than recommended VTFs, due to the possible 'chatter' of the stylus (where the theory is the stylus will momentarily lose contact with the groove intermittently, and possibly damage the groove when it 'lands' again in it). But I would expect such 'careening' around in the grooves would be audible as some sort of distortion, instead of even better sound!

 

Nice, there aren't many cantileverless designs around now, Ikeda had the MC version of the Decca London design in the 9 series, but I think he's moved to cantilevers on all the current designs. Someone just started a thread about the Ikeda 9 today here ... So This Showed Up In The Mail. Now I Need A Table

 

The optimum VTF is also temperature and humidity dependent, so note a summer and winter setting, if you live in a place with distinct seasons.
And also find your optimum VTF after the cart has been playing for a while and the cantilever suspension has become subtle, unless you like to listen for short periods only, say 30 minutes.
All good reasons why manufacturers provide a range!

 

I've landed on 1.88.
Not heavy enough to invite dullness; not light enough to kill the mids.
Recommended range is 1.80-2.00 with this cart.
Over the last week I've tried both extremes and everything in between.
It's not quite perfect yet, but it's pretty close for my ears (today, at least).
Still a couple of issues to nail. The mid range is one of them. Setting it to average out without either muddiness or lack of punch being too much of a factor across multiple pressings.

Test records, for reference, as follows:

Sgt. Pepper 1980 UK AAA.
Sgt. Pepper 2017 Remix.
Let It Bleed 2003 ABKCO.
Led Zeppelin I 2014 Reissue.
Surfing with the Alien 1987 US AAA.
Surfing with the Alien 2019 Reissue.

 

Some cartridges only sound best at an exact VTF. The Hana ML is one, and apparently the Umami Red is another, if the review of the Umami is anything to go by. The reviewer found that, if it was anything other than exactly 2.0 (meaning, based on MY Hana's experience 1.98 - 2.05), the sound would be "off." And that was my exact experience with the Hana ML.

I don't know if it's tracking force as much as VTA, though. I find that more significant.

However, I'd let the cartridge settle for another 30 hours before I spent too much time with VTF. It's still new.

 

I've been playing.

Interesting discoveries.

Oddly enough, there is actually a noticeable difference (on my setup, at least - which is modest) between 1.79 and 1.88. And, if you really want to narrow it down, there is a different between 1.84 and 1.88. That probably sounds ridiculous, but these are significant differences based on what I'm listening to today.

Test record was Laura Brannigan's 'Self Control' - UK 1st press, cut hot, great dynamics - using 'Lucky One' and the title track as reference points. At 1.84 the vocals and soundstage are huge. The mid range is adequate. What it misses, however, compared to setting the VTF at 1.88, is the analog warmth and genuine '80s' sound to the synth passages during 'Lucky One', which has got to be due to the emphasis on the mid range?

To my ear those passages are more pronounced, with a greater fidelity that just isn't present below 1.85 with my setup. In comparison, anything above 1.88 seems to kill the soundstage and the top end which, while still incredibly listenable, reminds me more of the CD mastering in many respects.

So that's the result of several hours tinkering with the VTF and a good scotch this afternoon.

I'm all set.

1.88 it is.

Until it isn't again.

 

No two cartridges are identical, and the VTF that correctly centers the signal generating element will vary from cartridge to cartridge for any given model. The ideal VTF will also depend on the behavior of the particular tonearm. This is why a range of forces is recommended. With the Audio Technica ART 1000 shown in Harby's post, above, the proper centering of the coils attached near the stylus is so critical that the manufacturer mounts each cartridge it makes and determines the precise VTF for each cartridge that properly centers the coils. That figure is provided with each cartridge. By the way, I've heard that cartridge and it is, to me, a fantastic sounding.

 

Before I posted the above I forgot to mention that I recently by accident broke the string that connects to the weight that applies anti-skate to my tonearm. It may be a while before I attempt to repair it, so I resolved to use it without anti-skate until then (if I do at all, based on my impressions so far). In order to minimize any uneven groove wear, I lowered the VTF to the recommended minimum amount of 1.5 grams noted above. To my surprise it sounded better than ever! More heretofore 'hidden' textural details, more 'open' sound, better dynamics, etc.

Yesterday on a whim I lowered the VTF even further to 1.39 grams, and whaddya know, the sound was even better yet! I played several records I'm familiar with to confirm this, and this has excited me. This afternoon after work I'll try it at 1.29 grams! I wonder how low I can get before signs of mistracking or distortion, which I've heard theoretically can damage the groove. Which brings up the question -- when the VTF is lowered by too much and the stylus starts to momentarily lose contact with the groove (then presumably strike the groove when it re-contacts it causing damage) -- shouldn't that phenomenon be audible somehow, as maybe momentary (or even continuous) distortion that can be heard?

 

Yes, mis-tracking will be audible. You will first hear it on loud passages, such as excess sibilance when a female singer hits the microphone hard, or instruments will sound like they are breaking up. More subtle signs would be instrumental sounds becoming a bit less clear, sometimes notes will sound "sour."

 

Thanks, I figured that should be the case. I'll be attentive then as I continue my experiments with lower than recommended VTFs. I'm surprised though that it keeps improving as I lower it, even below the recommended range. It might be a characteristic of the 'positive scanning' or cantilever-less design of the cartridge, combined with my oil-damped unipivot arm. Anyway, this discovery has been fun to experiment with.