I use the Mint-LP and think it's a brilliant tool. It allows a precision of setup that I don't think the Feickert's more conventional grid alignment method could match.
However, as you no doubt realise, the SME V cannot be adjusted for effective length because of it's unslotted headshell mounts. Thus an arc protractor such as the Mint-LP will be limited to cartridges with the same mount to stylus tip dimension for which the specific arc is drawn.
The Feickert on the other hand has more universal application (assuming one has an arm where the pivot point can be precisely located).
If you have (or plan to have) a number of cartridges of varying mount-stylus distances the Mint-LP approach would be impractical with the SME.
IMO, if you plan to keep the SME for a while, the sonic worth of the Mint-lp's precision alignment could well justify getting another template made (should that be necessary for your next cartridge). |
The SME V has a sliding base in order to provide for proper stylus overhang adjustment without the necessity of slotted headshell mounting holes. The SME V design philosophy is to have a completely rigid tonearm wand (which is also the reason the headshell cannot be rotated for azimuth adjustment.)
Supposedly, the SME V alignment templates provide for obtaining the proper stylus overhang, but I find them inexact (to say the least!) It's much easier to use a small thin metal millimeter scale placed carefully on the spindle with the other end supported on a rubber eraser or some such. Then with the anti-skating OFF, it's easy to set the stylus on the metal scale and rack the tonearm base back and forth to achieve precise stylus overhang right at the spindle.
After that it's relatively easy to use a DB or other protractor to adjust the cartridge parallel to the protractor gridlines at two points. |
Hi all,To use DerTonarm metaphor:'you think your stylus is in New York but your stylus is actualy in Washington'.
According to Yip (Mint LP)spindle diameter varies from 6,9 to 7,3 mm.BTW he asks 2 digit accuracy by the measurement:
7,16mm.
So 'exit universal protractors'?. I.e. if the premise is true.
Regards, |
Nsgarch,
the SME sliding base will provide overhang adjustment - but the effective length of the arm is fixed depending on the stylus to mounting distance of the particular cartridge. The base moves the whole arm, it can't adjust the length.
The stylus to mounting distance of cartridges can vary by several mm, meaning that the arc made by the stylus will differ slightly. Mint-LP tractors are made for a specific effective length (hence fixed arc).
A variation in effective length of the SME (by using a cartridge with different stylus/mounting distance) could make it impossible to align the outer points of the arc printed on the MintLp tractor. I'm not sure what the sonic consequences of this would be, but alignment accuracy would be compromised.
BTW, I'm happy to be proved wrong if anyone wants to jump in(?). |
Nobes, I understand your point, although I think "several mm" variation may be an exaggeration, especially with today's cartridges.
I'm not familiar with the use of the Mint alignment tool. However, I do know that a DB protractor gives accurate two-point tangency results so long as the stylus overhang is accurately adjusted for the tonearm being used. Small variations in stylus-to-pivot distance are apparently of far less consequence than an accurate (optimum) overhang setting. This is further illustrated by the fact that DB provides/allows a 6mm range of effective arm lengths in each of eight groups of arm lengths to which optimum overhang figures are attached. |
That is a lot of "accurates" attributed to the DB, which at best gives a close approximation of what will playback vinyl. :-)
You can easily hear the difference between 1/2 mm off and being even less, off. |
Dan, like I said, the SME alignment templates, though beautifully made, rely on 'by eye' guesstimates, which hardly cut it at that level of refinement; and I'm confident anyone who has ever used them would agree ;-)
The DB alignment protractor is also beautifully crafted and allows for very precise measurements; unfortunately though, DB leaves it up to the individual to figure out how to set the stylus overhang, and does not provide a tool for doing so. Failure to set overhang exactly, and the inability to use a Vernier scale probably account for poor results when they occur, but don't blame the DB. Used properly, I think it's as accurate as anything out there. |
Yes, accurate. To be correct I should comment on the basis of precision. Here is where I find the DB to come up short.
Thanks. |
I have an SME V arm and bought a MINT LP Tractor when I wanted to align my new cartridge. I have used nothing more accurate. Much better than the stock SME template. Yip is a pleasure to deal with and it is well worth the investment. There are a few Audiogon threads on the MINT and the SME fixed headshell arms. |
Nsgarch, you said:
"I understand your point, although I think "several mm" variation may be an exaggeration, especially with today's cartridges."
The two cartridges I use currently have a marked difference in the mounting position on my Graham arm. The Denon 103R sits pretty much mid-way in the slots (probably conforms to standard), but the Ortofon Jubilee sits quite close to the back of the slot. About 2mm difference, maybe more.
When Yip goes to such trouble to ascertain the *exact* diameter of individual turntable spindles (see post above) - you would be throwing away a lot of precision by not accounting for this type of cartridge variation when using the SME.
Of course, depending on the cartridges used, this may not be an issue. |
Tobes, I think you miss the point of the SME's brilliant design when you say "as you no doubt realise, the SME V cannot be adjusted for effective length because of it's unslotted headshell mounts."
First of all, with an SME there is no need to adjust the effective arm length. With standard mount cartridges, the stylus/pivot distance will always be 233mm and the overhang will always be 17.8mm; which is achieved by sliding the base back and forth. When the overhang is at 17.8mm, the pivot to spindle distance is automatically correct (no need to drill a precisely located hole in the TT armboard) and the cartridge, when adjusted true and parallel to the headshell, will be tangent to the grooves at two points; and if the cartridge is standard, one need only add the difference to the 233mm and look up the adjusted overhang (DB provides a chart) and you're in business.
My only gripe is SME's roundabout and imprecise way of checking the overhang -- typically British! However, the design objective of the SME V tonearm was to fashion a headshell/armtube/counterweight-carriage out of a SINGLE casting, in order to provide the most rigid platform ever conceived for mounting a cartridge; along with their use of outrageously expensive ABEC 7 ball race bearings that nobody else uses. So you see, the single hole mounting arrangement is not an arbitrary SME affectation, but works to locate the cartridge in exact relation to the other tonearm dimensions. Setup is really a snap with a standard cartridge andnot much harder with a non-standard one.
Granted, one gives up certain niceties to enjoy the unique attributes of an SME V tonearm. For instance you can't adjust stylus azimuth; but on the other hand, any cartridge worthy of living in an SME V should come with perfectly aligned stylus/cantilever; and if it doesn't? well at those prices, it goes back for an exchange!!
Adjusting the SRA (some call it VTA) can also be frustrating if you're expecting to just 'dial it in' like a Graham or a Tri-Planar. And if your (most likely modern MC) cartridge is too short, you'll need a headshell spacer to keep the back of the armtube from hitting the edge of the record ;-)
My advice to Pureretro: You have one of the finest, most foolproof, durable and easy to set up tonearms in the world. I've owned mine since 1990, and in 2004 sent it to England for its 200,000 mile checkup (they couldn't find anything to adjust!) and to update the internal wiring. That was it! So keep the DB and buy a nice thin metal mm scale so you can check the overhang accurately. (You'll figure it out.) And if your eyesight is shot, just get a great big magnifying glass ;-)
, |
Nsgarch, there is no need to try to 'sell' the SME-V's design to me - I owned that arm for two years myself back in 1989-91. In '91 I replaced it with the Graham 1.5T which I found sonically superior and allowed precise and repeatable adjustments of all parameters (I now have the Phantom 2).
BTW, I'm not putting down the SME - it remains a very fine tonearm. However, none of what you say changes any of the facts regarding effective length that I mentioned above and how that will effect a fixed arc tractor. And yes, the problem is real, as demonstrated by the cartridges I mentioned above.
I think that's something the OP should be aware of, nothing more. |
It is merely the difference between an arc-style protractor vs. the others that rely on a multi-step process. With an arc-style that is made for a specific effective length and P2S, there is no need to do the extra steps like checking overhang. These extra steps do introduce more error and the effects of those errors do add up. It is faster, and IME, much more accurate and I'm very grateful to those who introduced me to this type of protractor, and more importantly the Best Protractor. As many others have posted around here, Yip simply builds more precision into the Best Protractor.
The results that can be achieved with an arc-style, let alone the Mint, are much easier to realize and repeat. It is simply a better tool. Just compare the steps and movements you must make with the DB. Clunky is the word that comes to mind. |
Dear all,Assuming that the protractor problem is solved what about an accurate aid to measure the spindle-pivot
distance (spindel-dimensions included)?
Regards, |
That's the point! With an arc-style protractor made for the table/arm combo, there is no need to measure P2S. If you hit the arc, you have the dimensions set. So just finish up with the cart alignment. |
Dear Dan, If this is the answer to my question then we have
the problem that one can move the arm in relation to the spindle-pivot distance as well as move the cart in relation to the 'slots' on the heashell. With 2 moving dimensiona I am not sure about the result.BTW the slots are
to provide for the distance between the stylus-tip and the fastening bolts because this distance differ by carts.Or so
I thought. I am not a technical guy but I know that the spindle-pivot distance is fundamental.
Regards, |
Nandric, in all alignment procedures (except the SME) it's mandatory that a prescribed stylus-to-pivot distance (sometimes called 'Effective Arm Length') be maintained (thus necessitating slotted headshells ;-)
Further, a fixed arm length requires a specific (for that tonearm) spindle to pivot distance, and most tonearms come with an appropriate (though not always well crafted) template. If the one you got is sloppy, or non-existant, it's best to make your own out of a piece of acrylic. Slip one end over the spindle (with the platter removed) and, through a tiny hole in the template drilled the correct distance from the center of the spindle, scribe or draw an arc on the arm board. You can drill the arm mounting hole(s) anywhere along that arc.
Dan asserts that "With an arc-style protractor made for the table/arm combo, there is no need to measure P2S" (I think he meant cartridge/arm combo,) but unfortunately, this is true only if the arm mounting holes have been drilled, and the arm mounted with utmost accuracy, the correct distance from the spindle, per the tonearm manufacturer's specs. In reality, that is REALLY HARD TO DO without proper shop tools, drill press, etc.) If there's any doubt (and even if your TT came with the TA mounted) it's best to field-measure your particular equipment setup and provide the actual P2S dimension to the toolmaker prior to fabrication ;-)
. |
Table/arm. P2s and effective length are not dependent on the cartridge used.
Setting P2S is the responsibility of whoever mounted your arm, quite possibly the 'table manufacturer. So, yes, I can see the need to measure this ONCE when having a protractor made up because you can't really trust that the arm is mounted exactly right.
But then again, this is the beauty of articulating arm boards. You don't have one on your table? Sorry. ;-)
We've, well those who have been paying attention, covered all of this several times before. A search here will turn up past discussions on this. Bye. |
"P2s and effective length are not dependent on the cartridge used." True. They are instead dependent on the tonearm design and must not be changed. Providing slotted headshell mounting holes therefore allows mounting the cartridge so the exact stylus-to-pivot distance required by the manufacturer can be set, regardless of the cartridge's stylus-to-mounting hole dimension. So with (most) arms you need to be able to adjust the fore/aft position of the cartridge in the headshell. The spindle-to-pivot distance is also specified by the tonearm manufacturer/designer and combined with the specified EAL (effective arm length) provides the correct arm geometry.
Nandric: "BTW the slots are to provide for the distance between the stylus-tip and the fastening bolts because this distance differ by carts. Or so I thought." That is not correct. The slots are to allow one to shift the cartridge fore or aft until the stylus tip is the PROPER DISTANCE FROM THE ARM PIVOT ;-) That distance is called the 'effective arm length', and is pre-determined by the tonearm designer. |
Hello again. I realized that with the SME slide mount you can set effective length easily. I suggest people draw themselves a picture so that the relationships between these distances become clear.
Also, I suggest researching arc-style protractors. It is not necessary to check p2s every time you check cartridge alignment because the arc is drawn at the correct effective length and the arc is registered properly by the spindle hole.
Another advantage is that with this type of protractor everything is fixed in place, platter, protractor, etc., so there is no moving of the protractor (ala DB) while you are trying to hit a gnat's ass with the stylus. |
Dan, the SME slide mount moves the entire tonearm (pivot and all) back and forth, pretty much toward or away from the spindle. Moving this carriage does not change the arm length, which on an SME is 233mm from pivot to the tip of the stylus (of a cartridge with standard stylus-to-mounting hole dimensions.)
Because of the fixed cartridge mounting holes, the arm length of an SME (and pretty much ONLY an SME) wiil increase/decrease by however much more or less the stylus-to-cartridge-mounting-hole dimension deviates from the standard. I.e., if the stylus is forward of the cartridge mounting holes say 2mm more than standard, the the effective length of the SME arm will be 235mm, not 233mm. It's not a disaster though, because you simply have to increase the overhang a tiny amount (according to a chart) and everything goes back into proper relationship.
Personally, I'd advise anyone using an SME IV or V to use cartridges with standard stylus-to-mounting hole dimensions. It makes life easier and still leaves a zillion cartridges to choose from ;-).
Setting up proper SME arm geometry involves two steps:
1,) checking/setting the stylus overhang (using the sliding carriage base), and
2.) adjusting the cartridge horizontally to align with the gridlines of a DB (or other conventional protractor) at the two null points (there's enough play in the mounting holes to allow this adjustment.) And that's it ;-) |
Nsgarch, I hope you get the chance to try an arc-protractor and even better, a MintLp protractor. A good look and it is easy to see why there are much better tools available. Whatever works for you. :-) |
Dear Nsgard,To use an semantic argument: you think that the expression 'youngsters' is 'correct' but the expression 'young people' is 'incorrect'. But you must wriggle yourself to explain that your beloved SME V is not
capable to accomodate 'deviant carts' because the headshell
of the SME has holes and,alas,not slots. According to J.Carr the 'norm' should be 9,25mm but the problem is that
many carts dont 'obey' this norm. So what are the slots for? To get the right eff.length by 'correcting',so to speak,the 'deviant carts'. So we are talking about the same
thing.
But of more importance was my question about the'right aid'to measure the spindle-pivot distance,the 'deviant' spindle diameter included.
Your answer is something I know since 30 years: included by
your TT package. This will not do for me.I think that we
need to ask Yip (Mint LP) to provide such an 'aid' for the individual TT's.
Regards, |
Nandric: In recent years I have tried to stay with 9.52mm (not 9.25) for the distance between a cartridge's stylus and mounting holes, first because maintaining a specific distance makes it easier to swap cartridges, second because I am unaware of any other number that has ever been suggested as a possible cross-manufacturer standard. However, I have never heard any other cartridge manufacturer say that they consider 9.52mm to be a standard that they try to keep.
Looking at the various models in a single manufacturer's lineup, it appears that there can be variations in this distance. This has to do with whether the manufacturer even considers 9.52mm to be a standard, and it also has to do with the mechanical design policies of the manufacturer. Some manufacturers have a single basic mechanical design that they differentiate for different models with a variety of cantilever materials, core materials or outer bodies. For such manufacturers it should be easy to keep a standard mounting distance. Other manufacturers may have evolved through a lot of different mechanical design structures over the years (like us), or may have different mechanical design structures coexisting at the same time in their model lineup (like Dynavector). For these manufacturers, to keep to a single mounting distance is much more work, not the least because it may at times get in the way of other priorities for an individual design.
Therefore I wouldn't necessarily consider 9.52mm as a standard. A standard isn't a standard if the majority of people that it applies to ignore it, or obey it on a case-by-case basis. It would be useful if there was a database that showed the stylus-to-mounting hole distances for various manufacturers and models, but I am not aware of any such database. I don't even know if all manufacturers make such data known.
I agree that the combination of arc-type protractors and tonearms with fixed-hole headshells can be a headache. In reality, if the user understands tonearm geometry, it is not a problem to achieve Baerwald alignment even if the cartridge doesn't adhere to 9.52mm (and the effective length therefore changes). Simply recalculate and readjust the overhang (via the SME's sliding base), likewise for the offset angle (the difference in diameter between screwhole diameter and screw diameter should be enough to accommodate the majority of cases). The tonearm geometry will now be a little different from what SME designed for, and you most likely will need to switch to another alignment gauge (not an arc-type). Not as convenient, but the results should sound fine, which is the most important thing.
FWIW, different cartridge manufacturers appear to use mounting screw diameters of either 2.5mm or 2.6mm. Close to a standard, but not quite achieving it. Deja vu (^o^).
cheers, |
Nandric, Jonathan Carr (who manufactures the very fine Lyra cartridges) and I agree completely, even though I said it somewhat differently. I said: Because of the fixed cartridge mounting holes, the arm length of an SME (and pretty much ONLY an SME) will increase/decrease by however much more or less the stylus-to-cartridge-mounting-hole dimension deviates from the standard. I.e., if the stylus is forward of the cartridge mounting holes say 2mm more than standard, the the effective length of the SME arm will be 235mm, not 233mm. It's not a disaster though, because you simply have to increase the overhang a tiny amount (according to a chart) and everything goes back into proper relationship.
Personally, I'd advise anyone using an SME IV or V to use cartridges with standard stylus-to-mounting hole dimensions. It makes life easier and still leaves a zillion cartridges to choose from ;-). He said: Baerwald alignment even if the cartridge doesn't adhere to 9.52mm (and the effective length therefore changes). Simply recalculate and readjust the overhang (via the SME's sliding base), likewise for the offset angle (the difference in diameter between screwhole diameter and screw diameter should be enough to accommodate the majority of cases). The tonearm geometry will now be a little different from what SME designed for, and you most likely will need to switch to another alignment gauge (not an arc-type). Not as convenient, but the results should sound fine, which is the most important thing. I also mentioned, as Jonathan did, that there is enough play in the SME mounting holes to provide for offset adjustment if necessary. Neither of us even suggested (much less stated) that an SME IV or V arm could not accomodate ANY cartridge, and I don't know how you came to that understanding. As for variations in spindle diameter - well they can't vary too much can they? ;-) It's only important that a template hole fit over the spindle without significant play - an easy thing to fix (if it occurs) with a couple turns of teflon tape. Drilling the armboard so the mounted tonearm winds up the proper distance from the spindle is far more important in my opinion, and not as easy as it seems at first. My "beloved SME V" is the most rigid yet fluid cartridge mounting platform ever concieved. The fixed mounting holes are absolutely necessary for that achievement. In case you were unaware, SME makes a Model V with an adjustable headshell for those willing to trade the utmost performance for a bit more convenience. Neil . |
Dear Neil, I also admire J.Carr and you and he obviously admire SME V. We all are refering to some 'standard' that,as Carr stated, is not existant. His 'way out' regarding the SME 'hols': 'recalculate the arm geometry...'
The math was my worst subject at school but my best friend was an mathematical genius. He was not able to comprehend my 'weakness'. 'It is so easy' he was used to say.
No idea if Dertonarm was/is an mathematical genius but he
started this quest for the adjustment perfection and this seems to implicate 'thinking' in fractions of a millimetre.I got an reprimand from him because I stated that I hardly can see those 'little bastards'. Then Yip from the Mint LP come along with 'spindle deviations' and
well from 6,9 to 7,3 mm. To me all the spindles look exactly the same and I never thought about the subject because there was none. Or so I thought. I like Yip as well
as Dertonarm so I intend to keep my mouth shut. Those are
very sensitive guys regarding the mentioned 'fractions'and if you like that they like you,you should not 'mess' with
millimetre. You can always pretend that you obey all those
adjustments rules and even bay one Mint LP to look serious.
And if someone ask you:'are you listen to the music?' you
are supposed to say:'certainly not,I am still adjusting'.
Regards, |
Nandric & All,
right, --- am I listening to music? Sir, YES Sir!
Let's just say that (most?) SME V users fall a bit outside the anal-retentive mould of "sub-micron aligners/adjusters" and as long as they know where they fit into this "aligner/adjuster window", most unnecessary arguments can be avoided.
Even in Audio, it's a free world after all --- just don't come asking for advice on inner / outer or what ever groove distortion if you are a SME V owner, and there shall be piece.
I like mine, and have NO intention to change round holes for slots. When I had distortion it turned out to be the cart rather then the arm this far. (I measured some of those bastard carts, made my point and send them back to the factory for replacement).
Let's hold thumbs it'll stay this way in future -- SME V arm + bad cart = groove distortion, KISS :-)
Greetings, |
Axelwhal, believe it or not, there is a small coterie of SME V owners who are quite anal retentive. They're the ones who refuse to use the arm with the finger lift attached, and who remove the bridge across the main bearing. With all audio refinements/improvements/adjustments, proof of concept is always going to be decided by the answer to two questions: "Can you hear a difference?" and "Do you like the Emperor's new clothes?" No one who uses anything more sophisticated than a record changer will argue against careful setup - even those who haven't learned to do it themselves. The implication that certain arms/tools can provide 'tighter' setup tolerances is just baloney as I see it. I've been setting up arms and cartridges for 50 years, and I'm a stikler for precision in all things mechanical. The only changes I've witnessed in all that time vis a vis tonearm setup, are tools (such as Mint and Wally) that make the process easier -- especially for those who don't have a lot of practice and/or skill. What makes me laugh is the notion that one can do a better job using those tools. Maybe faster, but not better. If anyone using a line contact (or micro-ridge) stylus equipped cartridge really wants to experience a revelation in cartridge performance I would refer them to the following thread: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1140840022&openmine&Nsgarch&4&5&st0 Boy! Do I wish someone would make a tool for doing that!!~ . |
Nsgarch
y.s.:
>> ...the ones who refuse to use the arm with the finger lift attached, and who remove the bridge across the main bearing. <<<
No finger-lift, OK fine, I just put some heat-shrink over it so call me anal too. But removing the bridge is BS^2, call it crap, sorry. I have listened to it, it makes the sound in-coherent, period. (That arm was designed with the bridge and so was the sound or 'non-sound' it makes.)
As to that VTA tool, -- the longer I been fiddling with VTA, all the more I keep it with Roy Gandy's (REGA) take. It's important to find a good working level (and take some time to do it) but then get a rest and listen to music and don't keep on chasing 'sound'. Every cart has some sort of 'sweet-spot' but is not normally THAT small so we have to get anal about micro-degrees --- really it is not, and neither is all the rest from LP to LP. If it was, I'd been long, long back with this harmonically leached out CD music.
Greetings,
PS: taking care and practicing good set-up is one thing, getting 'retentive' quite another in my experience.
Enjoy a good weekend, |
Axel, you clearly did not read my thread on SRA.
"VTA" isn't even a real world entity (or concept or whatever) and is absolutely useless. People who think VTA is real are indeed doomed to "keep on chasing 'sound'" because VTA doesn't exist (unless your cartridge just happens to match the cutterhead in all dimensions and angles -- yeah right!) So just forget about it!
As for SME mods, I just don't believe in guilding the lily (or removing petals from it ;-) The SME arm is all about RIGIDITY and ZERO FRICTION -- both to the max. So I have to assume the bridge is there for rigidity, or else, as Bette Midler would say, "Why botha?!" As for the finger lift, I hardly think the tiny axial torque it creates will affect those huge ABEC horizontal bearings in the slightest.
. |
Howdy Nsgarch,
well now didn't I read that 'VTA' post, don't know, maybe I did? - didn't I read enough VTA stuff already? Uff...:-)
SRA, VTA, what ever, I do know the difference picture's right there in my head (as I said, didn't I read enough yet?).
I still use(d) the more widely 'used' terminology, it's less confusing with most folks - I think. (Like every UK dude weights in STONE --- then come the Kilogram, etc.)
I do not suggest to start yet another white-paper on the subject. If the stylus' contact ridge angle be always 90 deg to the cantilever it actually would be a perfectly interchangeable figure. Alas, this is not the case, so VTA ~ SRA are somewhat a bit more loosely related ~ by a couple of degrees at best.
As I said, take time out to optimize it for each cart/arm and then - peace be with you brother.
As to the finger lift 'story' we seem to agree on NOT mutilating, stripping down the V arm. It is not the torque (measured in uN/um of 'angel-wings' in this case?) but rather the resonance of this thing sticking out on the side. It's too practical for me to leave it off, putting heat shrink will take care of the resonance (at least in the audio band) so I guess nobody can say that I didn't try :-)
Greetings, |
Axel, please! It is NOT another "VTA post" ;-) You do me an injustice!
VTA and SRA are NOT 'loosely' related. In fact, they are not related at all! You really need to edumacate yourself if you want to discuss such subjects.
Yes, the torque of the fingerlift is miniscule compared to the resistance of the vertical bearings. Fingerlift torgue is an issue of course with unipivot tonearms. As for the 'resonance' of the fingerlift? Another 'audio chimera'. It is apparently made of spring steel, yes, but constrained only at one end -- so if it does resonate, be assured it's WELL ABOVE the range of human hearing and at an amplitude only bats could hear! Good God!! |
Hi Nsgarch
ok, ok, ok, so VTA is totally, utterly, completely, unrelated to SRA you say. So you'd be then saying that the stylus is also unrelated to the cantilever?!
And maybe then the stylus' contact-line is unrelated to the stylus?
Oh, oh, please gimme THAT link so I may also partake in this 'current fantasy'.
And in any case *SRA* is wrong also, since it should be then called *SCLRA* Stylus-Contact-Line-Rake-Angle, since the 'stylus' is only doing that picking-up via its 'contact-line' touching the groove, yes?
And as it so happens, the angle of the contact-line maybe just as unrelated to that 'clump' of stylus also!
As to the spring-steel finger lift --- you do recall that we are amplifying that pissy cart signal by 1000s of times and THAT - will make you hear a fly fart when sitting on your head shell, promise :-)
Greetings, |
I have the SME V and my dealer never installed the finger lift when he set up my arm and installed the cartridge saying that it made for a less direct connection between the mounting bolts and headshell. Is it audible? Probably not. I simply hold the headshell when I need to move the arm.
Can one hear the difference between the fixed SME V headshell and the detachable SME headshell (used for quick cartridge swaps and azimuth adjustment)? I never tried. It probably did contribute in small part to why my SME V sounds better than my old 309. I like the theory that the more rigid the headshell/arm interface and the headshell/cartridge interface, the better. |
Axel, here again is the link: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1140840022&openmine&Nsgarch&4&5&st0And in any case *SRA* is wrong also, since it should be then called *SCLRA* Stylus-Contact-Line-Rake-Angle, since the 'stylus' is only doing that picking-up via its 'contact-line' touching the groove, yes?
And as it so happens, the angle of the contact-line maybe just as unrelated to that 'clump' of stylus also! Technically you have a point, however, the usual fabrication of line-contact styli (except the Shibata) produces a shape that is symmetrical when seen from the front or the side. Thats why it's so relatively easy (as my photographs show) to determine when the "line of contact" is perpendicular to the record surface. Getting from there to a useful rake angle is a fairly simple calculation, and with some tonearms, a fairly simple procedure (NOT the SME unfortunately ;-( The idea of properly setting the SRA (again, only an important issue with line contact styli) is to have the ridges on each side of the stylus 'lean' forward at the same rake angle as the cutterhead (or did you think cutterheads were positioned straight up and down? Ever try using a chisel that way ;-) Ah the fingerlift again. Well, I don't care if you amplifiy it a million times, you won't hear it ;-) |
Hi Nsgarch,
maybe we have to set out our trades/professions for some helpful insights?
I'm a trained mechanical engineer and actually have even WORKED with chisels on METAL.
Next, I do furniture- and speaker-building, so again I use wood chisels (even Japanese double laminate ones --- and I sharpen them too, ho, ho). 25 deg. main angle and 30 deg. honed angle mostly, and depending on the cutter AND the tool.
Variations of 10 - 15 deg. depending on the application are not uncommon.
Yes, I did read that thread, not that it changes what I understand, but what I actually disagree with is the statement that the cutter-head is/was at ~ 1.5 deg (obviously tilted forward of the 90 deg. makes 88.5 deg. or 91.5 deg. so take your pick). In fact some 2-7 deg. seems closer to what has been the case when cutting lacquers or DMM masters.
This does in no way explain your take, that SRA is supposed to be NOT related to VTA...
VTA, is the angle between the flat record surface and the line the cantilever makes --- and the cantilever is bonded to the stylus at some angle greater than 90 deg. -- but it is then FIXED! So, how can the two then NOT be related, hallo?!
You are an architect you would understand what I try to get at, and I'm not talking just some numbers not being related here.
Depending on the angle between the stylus' contact-line to cantilever you can get either SRA or VTA, AND in fact those cart manufactures 'stupidly', 'stupidly', quote VTA (if they do it at all) and all then wait for us 'clever' audio-dudes to re-express it in SRA angle terms, wow.
If a cart manufacturer quotes 22 or say 25 deg. VTA you actually know squat about SRA -- because you do not know the angle that was used between the cantilever and the line-contact, or do you?
Do you know what angle the lacquer was cut at for the LP? No way, so you go fiddle your SRA or VTA angle until it sounds the best to your ears - and the rest of it is just a case of intellectualizing what we truly don't know, in terms of the actual degrees.
So you see, that's why I got a-plenty of VTA and SRA by now. Eish!
Axel |
Typical cutterhead angle is 1.5 deg. +/- depending on the lathe operator. I confirmed this with Stan Ricker, a well-known mastering engineer and lathe operator (Cardas Test Record.)
The precise angle of the cantilever to the record surface is irrelevant for playback. It can vary from zero deg. (for strain gauge cartridges) to 90 deg. (Decca cartridges) and everything in between.
However, ensuring that a line contact stylus' edges line up with the angled groove undulations is essential, no matter how it's attached to the cantilever, or what the VTA winds up being. Don't worry about those things.
It's nice to be able to adjust SRA on the fly to compensate for different record thicknesses and lathe operator preferences, but 1.4 degrees seems to be a good average if 'on the fly' is not possible (e.g. SME arms.)
If you set up your arm geometry carefully and adjust for close to the correct SRA (or exact SRA if your arm provides) that is at least 90% of the job.
It's then easy enough to check for correct azimuth with a test record, and for VTF by ear. Anti-skating force settings for line contact styli is about 25% that necessary for spherical or elliptical styli because of lower friction and groove drag.
If you'll follow this strategy, you can be confident you are getting the most out of your tonearm and cartridge. |
Nsgarch
I think we actually do not have a disagreement on the essentials. BUT if you have carts that like arm down (to keep it KISS) so the V's arm is just avoiding touching the record, I.E. down from level by 3-4mm. Yet another that likes it UP from level by a similar amount for the same record --- it is this what I'm talking about. What has changed is the angle between stylus' line-contact and cart mounting surface (at the optimal VTF) via the cantilever where it is mounted on.
Insisting on SRA is fine: IF I CAN ACTUALLY SEE IT!
Using that tool which produced the pic in the other thread OH YEAH, hurray!
So if I can't REALLY ascertain that 1.7 deg or what ever angle from vertical LP surface to the stylus' line contact -- then what is the good in riding on SRA? I have not the smallest issue with the theory, but in the end I need something more practical/useful I can work with, or?
Who wants to disagree with e.g. atomic weights, but I still get my sausage in pounds or ounces (in US I'd guess).
"Horses for courses" I make MORE mistakes setting SRA not really seeing what's going on, then simply listening --- so far at least my experience.
As nice as it might be to set the stylus contact-line to 1.7 deg. after I established that's what is needed for the record in the first place...
There are many such things in life, but for the practical current status a bit utopia I say.
You see already the MAJOR discrepancy in cutter angle statements! Roy Gandy has it at 0 - 7 deg. , your source knows or uses 1.7 deg. on you go.
In fact I think all of it has been used. So now you use this ASSUMPTION of how the record was cut to get completely immersed in setting SRA to the 1/10 of a degree. I'm sure it sound fine too, but because if it was 1 degree out it still sounded as fine.
Greetings, |
The implication that certain arms/tools can provide 'tighter' setup tolerances is just baloney as I see it. Well, I like baloney. Especially fried. So I guess that the rather large population of A'goners who have achieved better results using both the Wally and MintLP are just delusional? |
Well, I like baloney. Especially fried. So I guess that the rather large population of A'goners who have achieved better results using both the Wally and MintLP are just delusional? C'mon Dan. You know that's not what I meant, right? I'm confident, using my "stone age" methods, I can achieve the same precision as someone using a Wally or a Mint at least with my arm. But then, I've had a lot of practice, am very patient, and have a few tricks I've learned over the years ;-) It's not something I do often, so I'm willing to trade a little xtra time for a lot of xtra money. Heck, it makes me crazy just seeing my DB protractor sitting there in the drawer, staring at me! |
I was hoping that wasn't what you meant, and yeah, I do know better. ;-)
I think of it this way. I can use my framing hammer to do finish trim work, but I can get much better results with a finish hammer. |
But I really do like fried baloney! :-) |
