An easier way to set VTF/VTA/SRA? Perhaps....


I've occasionally advocated the need (over at Vinyl Asylum) for an additional alignment parameter in order to more easily find the desired tracking force (VTF) and stylus rake angle (SRA) interaction and easily adjust for changes in suspension elasticity. I refer to it as Weighted Cantilever Angle (WCA) which is the angle of the cantilever (from horizontal) where the manufacturer intended the cantilever to be positioned within the cartridge generator. (This would of course require manufacturers to provided the intended WCA for each cartridge.)

To align for WCA, a small angle gauge would be placed on the record surface to determine the cantilever angle as tracking force and tone arm height are adjusted to keep the headshell/cartridge body level. When the combination is found whereby the cartridge body is level and VTF and VTA/SRA provide the recommended WCA, then the optimal vertical cartridge alignment should be very close and only need fine-tuning.

The weighted cantilever angle could be easily checked periodically to see if there have been changes in the suspension.

Do you think this idea has merit? If not, what are the flaws in my thinking?

Tom
tketcham

Showing 5 responses by dertonarm

Hi Tom, the big problem is, that this will not work with a cartridge not fully broken in yet.......
Unless the cartridges suspension hasn't adapt to ambient conditions and hasn't reach its full velocity yet, the idea of the "WCA" won't give the right result.
Next problem is, that the cartridge designers won't supply any such thing.
It would force them to work even more precise and will give them no further USP if they incorporate such a "helping hand".
I guess most would fear that this would arise even more questions by the customer.
There have been designs in the past which did perform 100% right out of the box with very little to none variation in velocity.
Mainly cartridges designed and sold for broadcast (EMT, Ortofon SPU, Fidelity Research FR-7 series, Supex).
The better of these (FR, Supex) do feature a suspension which does keep its velocity from day one for over 30 years.
Todays cartridges - especially the Top-flight ones - do not feature any such thing.

In general setting the "right" "WCA" can be performed by looking through a highly illuminated magnifier from the front into the body of the cartridge and see, whether the cantilevers diameter is center in the yoke.
This however can't be seen on all cartridges - but on many.

But even this would only give a momentary result - changing in case the cart isn't broken-in yet.

There is no free lunch - it is still a game with a wide selection of important parameters which all need attention and skill to fine-tune.

If cartridge designers could agree upon strict mechanical parameters for all cartridges - that would make such optical settings much easier.

But so far we are left in the dark and have to trust our ears.....
Well, the cartridge manufacturers do already provide the parameter to set the VTF right: - their recommendation of the range the VTF have to be set in.

We will get no more and there is good reason why.
Aside that there is no monetary reason for the cartridge manufacturer to add any mechanical "helpers" - there too is little need.
Analog cartridges for the high-end customer is a luxury market with highly emotional customers. Nothing to quantify - nothing to determine the quality with any measurable parameters.
Similar to high-priced jewelry (at least there are quantifications like purity of precious metal, carat etc.), high performance cars - you name it.
Its individually viewed AND judged performance and personal preferences.

I guess - as frustrating as this might look on first sight to some - that we are doing quite well the way it is now.
Unfortunately this means that setting up an individual analog cartridge to fully show its abilities will always require skill, knowledge, experience and very precise handwork.

But then most of these are needed in all real passions.

There is hardly ever any free lunch out there.

Cheers,
D.

We all agree that a cartridge usually needs some time to reach its designed for operating conditions (velocity). Furthermore we are looking at a bundle of other depending parameters (tonearm, cable, matching impedances, inductances etc.) in interaction with the cartridge and thus influencing its sonic performance.
Next in line is individual sample differences within a production design.
No two cartridges of a given production design are truly identical in the technical sense nor in their technical parameters.
After all most are hand-trimmed or fine-tuned and so they are similar and go for a similar "family"-sound, but are not identical.

We will always need a range to work within.
Nsgarch, there are indeed only very few cartridge featuring a suspension which does need little to no time at all to "settle" or "break in".
To name the very few:
EMT, Fidelity Research FR-7, broadcast version of Ortofon SPU.
All these do have in common, that they were designed and initially made for broadcast use. Means they need to give 100% performance right out of the box.
And thats what they do.
Let me add further, that at least the FR-7 series does feature a very unusual suspension indeed. To this day, I have not found a single FR-7 cartridge which does not perform to specs. The last production run was 25 years ago. I have had over 3 dozen samples of this cartridge-family gone through my hands. All performed within a very narrow window within specs. Outlasting every other cartridge.
Worth mention I think.
So high performance can go hand in hand with extreme durability and 100% out of the box.
My 2nd back-up cartridge has by now the 4th stylus since 1988. Still running and sounding the very same way it did 2 decades ago.
The EMTs suspension however won't last a fraction of that time.
Nsgarch, while I agree with you regarding the vast majority of custom MCs and their behavior, let me briefly add, that the 3 MC mentioned by me are quite different in their mechanical parameters.
The Ortofon is indeed asking for 3.5 + grams VTF, but the EMT and FR-7 are around 2.2 and 2.6 respectively.
The EMT isn't all that low compliance and has a lifespan of less than 3 years in use.
The dynamic compliance of the FR-7 and SPU is around 7-9, but indeed mark the low bottom of the range.
These 3 cartridges do perform to specs right out of the box NOT because of certain extreme mechanical parameters, but because they were designed and made to do so - as they had to meet broadcast (read: professional) standards.

While I agree that the SPU and EMT may not be up to full modern day standards in terms of overall sonic balance, I (...well known by now...) still have to mention, that no today cartridge is up to the overall sonic performance of the more refined versions of the FR-7.

I have mounted, aligned and heard extensively EVERY top-flight cartridge of the past 3 decades - with every top tonearm you name and in high-priced and quite sophisticated set-ups.

Very low output brings back the topic of high class matching SUT.........
Regarding SRA and the adjustment to meet the cutting angle of a given record. ...
This was widely done in the late 1980ies first among the initial collectors of the audiophile quality early stereo records (DECCA SXL, Mercury SR, RCA LSC, EMI ......).
The difference in a 9-10" tonearm "relative height" ( or resulting SRA...) between the cutting angles of say a modern day Opus3 and a 1959 Mercury or EMI ASD/SAX were 1/2" (12-13 mm).
I am serious - these are not marginals.
The differences are huge.
Widely - if sadly .. - neglected and forgotten by todays audio writers and magazines.

God - as well as the tiny devil - lives in the details.