Has anyone here ever played around with "Rake Angle"?

I have recently been looking into "Rake Angle" on my Linn Basik/Akito 2.... Normally I adjusted the arm height so the arm was level with the average record surface and thought no more about it.

However I read a few articles about adjusting the "rake angle " to around 92 degrees , so I did and it seemed to make quite a difference. I found a more balanced audio spectrum, better stereo image and better attack on piano and guitar and better tracking.

I also have a Technics SL D 303 which needs a shim to adjust the "rake angle" so I applied this and this too yielded the same results.

Now I use quite a modest cartridge : an Ortofon OM 10 , which has a bonded elliptical stylus but , it doe seem to now give great results....

Have you been down this path? What did you find ?
 

Wntrmute2

Not So Mediocre Member
I am assuming you used a USB scope. Could you share your set-up and any pictures you might have?
 

fiddlefye

Senior Member
Yes, every time I set up rake angle gets involved. Some carts seem to sound best level, but others prefer to be a bit nose or tail down. On the other hand all of the arms I use currently have VTA adjustment so nothing as tedious as shimming is involved. I usually just start a bit nose down and lower the arm in as small increments as I can until I find what I like best.
 
Yes, every time I set up rake angle gets involved. Some carts seem to sound best level, but others prefer to be a bit nose or tail down. On the other hand all of the arms I use currently have VTA adjustment so nothing as tedious as shimming is involved. I usually just start a bit nose down and lower the arm in as small increments as I can until I find what I like best.

Yes it does seem like that but I was surprised that "tail up slightly" seemed to make quite a difference
 
I adjust it by ear, though without a microscope I really can't be sure what angle I end up with.

I have done that too, I notice that if you mention "rake angle' you get two schools 1) The USB microscope and the scientific approach and 2 ) the fiddle about and see what happens.....BY nature and training I should be in school 1 but to be honest that is a lot of effort and I just tried a little fiddle and see . However I was surprised , I just moved the tail up a bit a few times and eventually I hit a sweet spot . It worked on two of my tables and both with only a modest bonded elliptical. It was not day and night but rather like using the fine focus on a camera to get the final sharp image . It was sharp too: the bass mid and treble slipped correctly into place, the image became pin sharp, tracking was better, sibilance was absent attack was better on piano , guitar and drum beats.....I could go on and all from a modest cartridge really...
 

JohnVF

Administrator
Staff member
I have done that too, I notice that if you mention "rake angle' you get two schools 1) The USB microscope and the scientific approach and 2 ) the fiddle about and see what happens.....BY nature and training I should be in school 1 but to be honest that is a lot of effort and I just tried a little fiddle and see . However I was surprised , I just moved the tail up a bit a few times and eventually I hit a sweet spot . It worked on two of my tables and both with only a modest bonded elliptical. It was not day and night but rather like using the fine focus on a camera to get the final sharp image . It was sharp too: the bass mid and treble slipped correctly into place, the image became pin sharp, tracking was better, sibilance was absent attack was better on piano , guitar and drum beats.....I could go on and all from a modest cartridge really...
The final focus on a manual camera is a good metaphor. I start a little low and move past vertical to hear when it locks in. It gets to a kind of liquid sound. No harshness.
 
"Abrasive wear generally causes damage in a single action. The hard particles of one surface or particles which are entrapped between two surfaces cause a permanent change in the physical dimensions of the other surface on their first pass over it. The most important factors which govern abrasive wear are the number of hard protruding particles present, their shape, and their hardness. The wear which occurs can be deformation with no material loss or it can cause particle formation (material removal). Which of these occurs depends on the material properties of the abrading particles (either loose third-body particles or asperities on the opposing surface) as well as material properties of the abraded material. Sometimes when a material is only deformed and no material is lost (no weight change), the wear mechanism is termed plowing. Continued plowing, however, can eventually lead to wear debris. Rigney and Glaeser state that the repeated plowing of asperity contacts over a ductile mating surface can produce high dislocation densities. This brings about an eventual change in the microstructure which assumes a cellular pattern characteristic of heavily deformed metals. This structure presents many favorable sites for subsurface cracking and the eventual release of thin wear flakes [21].

Cutting or scratching has been used to describe when material is removed in an abrasive manner. The wear scars are different for the plowing and cutting modes of abrasive wear. Mulhearn and Samuels have shown that the angle which an abrading particle makes with an opposing surface can determine whether plowing or cutting occurs. This "critical rake angle" often determines the transition between cutting and plowing [22]. Most of the abrasive wear models include geometric asperity descriptions, so that wear rates turn out to be very dependent on the shape and apex angles of the abrasive particles moving along the surface. If a significant portion of contact events is of cutting type, abrasion is a form of wear which is relatively efficient [22]. Cutting type behavior depends on the mechanical properties, especially hardness, of the surface which is being worn since cutting requires indentation. The wear debris generated from cutting and plowing type events can differ considerably.

Any wear situation can be thought of as being part of a spectrum with (micro)cutting at the left side (most effective) and less efficient wear mechanisms such as smooth sliding towards the right. In this representation, the overall abrasion processes are intermediate, with the most efficient ones towards the left (mostly cutting) and others further right (less cutting, smoother sliding) [23]. Abrasion is most effective when microcutting dominates. Microcutting occurs when hardness differences are sufficient and when local rake angles are appropriate. The debris particles generated are usually cutting chips with a composition basically identical to that of the abraded material [24]. Where a given situation falls depends on the factors mentioned in this section. Lubrication may have little effect on abrasive wear and in certain cases adding a lubricant may actually increase the wear rate [25]."

For the best sound and least wear find the fine line between the cutting and plowing wear mechanisms. :)

 
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I have recently been looking into "Rake Angle" on my Linn Basik/Akito 2.... Normally I adjusted the arm height so the arm was level with the average record surface and thought no more about it.

However I read a few articles about adjusting the "rake angle " to around 92 degrees , so I did and it seemed to make quite a difference. I found a more balanced audio spectrum, better stereo image and better attack on piano and guitar and better tracking.

I also have a Technics SL D 303 which needs a shim to adjust the "rake angle" so I applied this and this too yielded the same results.

Now I use quite a modest cartridge : an Ortofon OM 10 , which has a bonded elliptical stylus but , it doe seem to now give great results....

Have you been down this path? What did you find ?
" Nearly all users in the world (and there are many) have totally misaligned setups without knowing."(M Fremer)

Fremer's ZENITH ANGLE CORRECTION or have we all gone crazy.​

The sharpest brains on the planet (the analog planet that is)discusses this "alignment" at this very moment at the audioasylum/vinyl asylum!

 

JohnVF

Administrator
Staff member
" Nearly all users in the world (and there are many) have totally misaligned setups without knowing."(M Fremer)

Fremer's ZENITH ANGLE CORRECTION or have we all gone crazy.​

The sharpest brains on the planet (the analog planet that is)discusses this "alignment" at this very moment at the audioasylum/vinyl asylum!

I remember Fremer saying you couldn't set it by ear, though I kind of agree with the poster in that thread who said if you can't set it by ear, then why worry? I have always in this hobby, especially the turntable part, had to balance my enjoyment against finicky OCD. At some point it gets so in the weeds that I don't enjoy it anymore, and so then what's the point? Pay all this money to torture myself? That said, we're all different and some people aren't as easily annoyed or even enjoy such a degree of perfection, and hat's off to them. I appreciate folks like Fremer, without myself wanting to be like him. His Analog Planet site is quite a bit more entertaining and light-hearted than his Stereophile persona.

I use a Dennisen protractor to get cart alignment close (though with some S or J-shaped arms using the overhang spec works better for me).. and then I go about playing with getting the stylus square in the groove (sometimes it sounds very slightly off when visually square), and finally VTA/SRA. It really helps to have an arm where you can easily do fine adjustment of it like the Technics EPA arms, or my Jelco TK-850s which has an aftermarket VTA base on it.
 

JohnVF

Administrator
Staff member
One thing I should add... I haven't gone to the crazy Fremer degree in the past because I used to switch out carts like a crazy person. Every week I"d have a different cart running. Moving into this year I'm going down to two turntables with permanent carts. A re-cantilevered Ortofon Cadenza Bronze on a Sony TTS-8000/EPA-100mk2, and a Dynavetor XX2 on a Merrill-modified AR ES-1/Jelco TK-850s. I actually have the tools to do this correct...a USB microscope and a Fozgometer Azimuth gauge, so I actually -may- do it the finicky way for once.... Because the results will be left alone for a long time, and not become the victim of me wanting to just screw around with something else.
 
However I read a few articles about adjusting the "rake angle " to around 92 degrees , so I did and it seemed to make quite a difference.
I do the same, with a USB microscope. It mimics the cutting head angle and thereby reduces record wear, on top of sounding better. This was a theory from decades ago, and Fremer brought it to light in recent years. It is much more critical on the "line contact" type of stylus where there is a sharp and long contact patch, vs. an elliptical or spherical. I don't crank on the VTA as a tone control, in other words.

I do check zenith angle as well, but visually rather than with an oscilloscope. Although that's my next step.

I bought one of those Mint Protractors and it revolutionized my setup process. The Dennesen I have from ~1981 is too much guesswork. This one is based on a mirror, plus the way the lines are scribed on the glass makes sighting the cantilever to get it straight a much easier process. I believe @Wntrmute2 owns one as well.

I just hate setting up cartridges--my eyesight is shot, and my fingers aren't nimble anymore. Something I could do in 15 minutes now takes over an hour.
 

JohnVF

Administrator
Staff member
One thing in regards to that Fremer audio asylum thread and the Analog Planet article it references...Fremer is using what is essentially a very poorly manufactured cart to make the case that you can't adjust it by ear, because that particular cart would need the arm lifted 2cm to be at the correct SRA. The assumption there is that its not an outlier, but it is, and he even says that if you were to own that cart you should send it back for a properly manufactured one. My assumption being.. you actually can do it by ear, to some extent, with a properly manufactured cart.
 
Funny I also use recordings of the acoustic bass to set my VTA/SRA by ear!
It is an instrument I know very well playing beside one for many years.
Foremost Rob Wasserman-Duets & Dave Holland Quartet-Conference of the birds & Nils Henning Ö Pedersen/Sam Jones -Double Bass
 
Recordings of the acoustic bass is also a useful tool when loading your moving coil cartridge to get the "right" amount of loading
and the "procedure" is for me almost the same!
When the acoustic bass "snaps in" and become "life like" You are there!
 
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