Raul,
After this explanation, I am going to have to give up on this. I will stipulate that all the numbers you have provided above are correct. No dispute there.
I tested the original claim from many months ago (with an estimate I have labelled Dert63 above) against the original reference (245mm EL Baerwald or Lofgren). One does not, in fact, have to compare everything on a common P2S or common EL because in fact, the original claim did not.
In this thread, he made certain VERY specific and precisely qualified claims. Those claims were VERY clearly made on the basis of a certain opinion about record size (hence my use of DIN standard) and his own listening priorities (reduce distortion in the latter half of the record at the expense higher max distortion at the beginning), i.e. use a weighted distortion curve rather than an un-weighted distortion curve. Again you ask for proof. He wouldn't provide it, for what I now clearly see were good reasons not to, but I was curious, so I derived what I could based on these claims. As I have shown, each one of the claims seems to hold up when one does the math.
To my knowledge, NOBODY (not myself, Dertonarm, or anyone else) has EVER disputed the 'fact' that over a whole record, Lofgren B and Baerwald/LofA have lower average and lower equal-peak un-weighted tracking distortions than any other solutions for a given effective length. It is just math. Everyone stipulated this point long ago. Just to be safe, I repeated it.
His opinion about the qualitative aspect of tracking distortion across the record is clear. His listening priorities are clear. Based on his 'weighting', he has recommended and used something else than standard. That is his choice. As 'proven', his priorities would absolutely support use of Dert63 vs either of the Lofgrens. As you said, there are no 'absolutes' other than the math. It is some people's opinion that 'math' can be absolutely perfect in theory, and still applied wrongly sometimes.
The math stands up to support his priorities. The math stands up to support your priorities too. Everyone needs to make their own choices about priorities. I leave it there.
Kudos to Dertonarm for staying out of this. I should have as well. |
Thanks D. I think I can see why people would like it. And I agree - all it has to do is suit one's needs and work well, and it would seem to be a better solution than the template provided with the arm. It is good to be open-minded about one's own priorities and be able to question the 'establishment' standards, even if it makes you a criminal in the minds of the 'authorities' or the moral police... :^) |
Dear T_bone: I hope that with this post I can finish my intervention on this regard.
IMHO all these numbers/calculations for geometry cartridge/tonearm set up is in many ways something " academic " and very informative for the best part.
I already posted but maybe you or other persons don't remember:
++++++ " But I don't finish yet, we have to take in count too the LP characteristics and characteristics on was is recorded there: off-center LP hole, waves all over the LP, different recorded velocities at different areas in the LP surface, thickness of the LP, resonance of the LP build material, etc, etc..
These LP characteristics has an influence too in the cartridge quality performance. " ++++++
all our discussion on the subject about numbers are on static cartridge/tonearm status with no single sound in our ears coming from the speakers.
All those distortion level numbers prevail on dynamic cartridge/tonearm/LP motion/playback? , IMHO did not.
Now, imagine just for a moment what happen when an audiophile likes to be anal about SRA/Azymuth/VTF ( that I insist IMHO are a little more critical and important that that geometry set up for the " Mercurys ". ) set up on motion/playback and he changed all or one of these parameters with any single recording he is listening ( for whatever reasons you could think. ).
Any single change on SRA/VTF ( between other changes in set up cartridge parameters as LP off-center hole or LP waves/non-flat surface, etc, etc. ) change the position of the cartridge stylus tip and if he/we want to stay 100% accurate with the set up cartridge/tonearm numbers calculated he need to re-set this geometry set up each time he makes changes on those other cartridge set up parameters!!!!!, " crazy " don't you think?. Whom will take care about and why?.
As some one posted here: " we are to enjoy listening music " and not for changing ones and again the geometry set up cartridge/tonearm each time we change SRA/AZ/VTF with new calculations!!
That's why I said all that is in some ways: academic and informative.
That's why almost all of us made cartridge SRA/Azymuth/VTF set up by " ears " and this means on: motion/playback status.
We can´t have " absolute " control in our beloved extremely imperfect analog world named: LP. Each one of us according each one priorities and knowledge level made and make the best we " have on hand ".
regards and enjoy the music,
Raul. |
Raul, now you're talking what I have been a few pages before. Numbers and numbers don't matter. We care about the sound and about enjoying the music and not numbers. No absolutes. Nothing is and nothing will be. We are free to try and make up our minds. Not with numbers, curves and distortion figures but with the results we hear.
LP is basically a flawed or imperfect meduim like you just said. We all know that and make the best out of it.
Thank you and enjoy the music |
Dear Dertonarm, I had no idea that K. Remer passed awey so
young. Was this the reason for 'passing awey' of the Magazine? I still regard DAS OHR as the best HI-FI Magazine
ever. The peculiar methodology was that each component was revieuwed by two revieuwers to further 'objectivity'. My
estimation is that you was then 20 (?) years old so this
HI-FI virus you got already as a kid. Talking about passion!
Regards, |
Dear Raul, One of the problems of an perfectionist is the
'endless list' of wishes. But before we start the second round reg. the coplexitys of our records I like to mention
in advance this peculiar capacity of (I hope only) man to 'ignore noise'. Probable caused by evolution of us 'the
hunters'. A friend of my lost his hearing capability and
need to use those hearings devices. His greatest problem is to understand his conversation partner in a gathering.
We all,I think, assume this capability for granted. But
there are among us those who collect all kinds of old records and it is very difficult to presuppose that they are not enjoying them. So my quess is that this is only possible thanks to our capability to ignore the noise. I hope that you or Lew can find in your study books 'the explanation'.
Regards, |
Dear Genesis168: +++++ " Numbers and numbers don't matter. " +++++
this is not what I try to explain in my last post. Your statement is to " dramatic " for say the least.
IMHO " numbers " always matter if you know where and how matters and its importance level ( your skills to interpret/translate what numbers are saying. ): where numbers makes " the differences "?, when you have the answers to this question you will understand the importance of numbers.
Of course that are " numbers " and " numbers ", some makes a difference, some did not and some are informative or just academic.
As an examples: we need numbers to make the cartridge/tonearm set up ( overhang or pivot to spindle distance. ), sensitivity/efficiency speaker level, RIAA eq. curve deviations, current power capacity on amplifiers, damping factor, room/speaker set up, etc, etc.
With out this kind of " numbers " we can't make/take and decide from different alternatives for the better.
Till today I still support that if we want to improve the quality performance level in our each one audio system one of the best way to go is: lowering distortions ( every kind ) in every audio link in the audio system chain.
In some of the audio links the " numbers " ( for accuracy levels, frequency range, THD, IMD, deviations, etc, etc. ) help a lot to decide what to do and you know what: our ears heard it.
Of course that " numbers " does not matters if what we are hearing is a poor and low quality level of sound.
I'm like you on the main importance with the quality level in the sound we listen through our systems and all my " ideas " and " adventures " that I take in my system ( changes. ) have as only target: improve its quality performance level and this IMHO you can't do it with out subjects as: accuracy and " numbers ".
I'm for a good sound in my ears but over this I always prefer a good accurate and " non-distortions " sound reproduction that only " good sound ".
IMHO I think that we should not be on these extremes: only sound or only numbers.
How good are our skills/knowledge levels to make " the right " blend/mixture on those extremes is what will define the quality level in each one audio home system.
Of course that as you posted: " We are free to try and make up our minds. ".
Regards and enjoy the music,
Raul. |
Dear Nandric: I don't have yet the right and precise answers to:
+++++ " our capability to ignore the noise " ++++
but a priori IMHO I think it is a phsycoacoustic subject and the enormous capacity that our brain has to adapt over time to " continuos " stimulations " like LP sound and its enormous capacity for " discriminaty " what we want to discriminate.
In the other side IMHO we music lover´s always enjoy music it does not matters the source quality level.
In other thread I posted that I'm preparing the information for a new thread with may " new " experiences on a very interesting subject that by coincidence one way or the other take in count this noise subject you are talking about. I hope to post that thread next week.
Regards and enjoy the music,
Raul. |
I think we all want to learn from your findings about noise.
But the rest of us who were using tubes (& LOMC) we are in a deeper hole. |
Dear Geoch: The thread's subject is not mainly focused on that kind of noise " that mantain you on that deeper hole " but something more related to improve that " hole ", each one system " hole ".
regards and enjoy the music,
Raul. |
Dear Nandric, it was a really sad and dramatic end for Klaus Renner. And yes - since DAS OHR was literally his "baby", there was no way it outlasted it's father and founder. It was one of the very few magazines ever totally independent from advertising and self-financed.
I started with high-end in the late 1970ies when I was 16.
My first speakers were K + H studio broadcast monitor speakers (type OM I think ) with built-in V69a Telefunken tube-amplifiers bought used from Bavarian broadcast service in Munich.
My first encounter with serious turntables were Micro Seiki RX-5000, Mitch Cotter B and Platine Verdier serial # 1.
And my first "real" tonearm ...... FR-64s...;-) ..... a good friend since 1980.
Nice memories of days gone by.
Cheers,
D. |
my first impression with the Uni-Protractor is: very well built quality, the magnifying glass is just great. Very precise alignment is possible. Now I need to test the 8 different tonearm specific inlays, will report... and discover new possibilities maybe... |
Thuchan:
Looking forward to your more detailed impressions of the uni-pro. Just received my tracking # so I should have mine shortly. |
Jazzgene, I suppose your name gives a hint to your favourite music, this fondness we share! while you might already have unpacked your Uni-Protractor let me describe my experience after having aligned two tonearms, the SAEC WE 8000 and the FR-66s.
I used to take the Dennessen when I start aligning which I regard for most of my tonearms as an absolutely appropriate tool. In the beginning I was a bit sceptical also being influenced by the controversial discussion in this thread.
When I started with the SAEC the difference was not only one or two mm, the original SAEC geometrical data for the WE 8000 suggest a completly different set up. I had to bring back the cart for about 4mm which was not easy having to tackle with the special WE 8000 headshell. In the end the musical result is fine. I have to admit I also liked the Dennessen position.
Nevertheless this motivated me to try it with the FR-66s (images on my
page). Here the difference was only 1mm, hence a small gap which can make you happy or not.
I played back with the EMT JSD 6 Jubilee Series, originally designed for my EMT R 80 - coming with an EMT connection. Thanks to a wonderful adapter (from EMT to SME) it also matches with the FR arm. I have to admit this is not only a great cart but having it aligned with the Uni-Protractor it plays precise, provides subtle and detailed information and is also able to drive forward - offers a mellow push.
Dealing with the Uni-Protractor is much more easy than I thought. Of course you have many parts, in my case 8 inlays, but you may keep the Protractor within reach when dealing with different carts and tonearms - for me it is a very good instrument. |
My, my , this is bad. I think the price will go up. Daniel, promise no price increase for 2nd batch.
Cheers, |
Dear Mesael, I am sorry, but the production costs of the UNI-Pro (linear drive especially) proofed pretty worse in the 1st production run.
Everything with the UNI-Pro is custom designed and many parts needs to be custom made.
Aside from the micrometer screw there are few parts we can actually use without alternation.
The 1st production had a special introduction price and sold out (35 units) within 2 weeks.
Furthermore the ever declining value of the US$ vs the EURO left no choice here but to raise the price and to separate the shipping costs.
We are confident however, that we can keep the price tag of the 2nd production run where it is now.
Cheers,
D. |
@Thuchan,
I listen to mostly classical although I don't know if you can call artists like Xenakis "classical" but that is someone I am studying right now. I play jazz for a living!
Anyway, I can only be so lucky to have received it yet. Still waiting for my Uni-pro. My main concern is the ease of use which Mint did not provide and Yip shows poor customer service with. Also precision is very important. Looking forward to using it. |
We are confident however, that we can keep the price tag of the 2nd production run where it is now. don't forget, this is a price without the usual Importer and Dealer mark ups. When selling it that way, most of you know what area will be reached. This is unfortunately one of the main problems in High end audio. When done right (expensive but superior parts) it is out of reach for most discriminated Audiophiles. When forced to cut costs, it can be made in cheap plastic. With black glossy finish. In a way it was done wrong. Starting with cheap plastic for 700 and giving a nice rebate... Btw. can I have mine with a 24k Gold frame? |
I do recall the original stated price was slated till... March. Afterward would rise $100. I do recognize the value/quality of this tool. I'm a watchmaker who has/uses/appreciates many examples of fine european tooling. |
Dear Daniel,
I understand, just making a jest on the price. To deviate from an accepted norm really need a lot of courage.
I'll make sure my order will be included in the 2nd batch.
I know you've sold many Davinci in the past. My tonearm is 12" Grandezza and my lps collection are mostly 70s to 90s rock and new wave, and current reissues. What templates should I get?
Rgds, |
Have been following this thread daily since it started and have ordered mine.
Received confirmation of my UNI-Protractor, #38.
Can't wait. |
Dear Mesael,
I do have calculated and designed a special UNI-template for the DaVinci 12". Aside from that, I would recommend Baerwald DIN and IEC as well as Löfgren DIN. That would cover about everything that can come across your way in terms of tonearms and pressings.
The UNI-Protractor's 2nd production run is already down to only 12 units left till sold out again.
Tonight I will introduce the UNI-scope here on Audiogon.
A superior option to magnify the cartridge's stylus on template by 20 - 200x with a special USB-microscope + macro-cold light + PC/MAC-view, photo storage and measurement option.
Including plug'n'play software for PC-Windows, MAC OS-X and Linux.
Furthermore ideal to judge wear or possible damage of stylus.
The UNI-P2S w/goniometer - an ultra precise mounting distance measurement instrument w/digital display and 1/100 mm accuracy will be introduced later this week.
Both are Audiogon exclusives and intended to further amplify the versatility and precision of the UNI-Pro.
Cheers,
D. |
I made a few comparisons with a very close to perfect Alignment and a perfect Alignment. When we multiply a regular Tonearm by Factor 100, the Arm is about 27.34yd (25m) in Length, the Cartridge System is about 1.09 yd (1m) in Hight with a Length of the cantilever in the area of 0.55 yd (0.5m) and finally the Diamond specs: Its contact area is only 0.020 in. (0,5mm) ! Same is for the Mass in comparison. A simple example to show what analog reproduction really is ... Of course, all of you know that it is important to be spot on, but what is the difference in real life? Well, I used a RCA LSC 2313 for it, a nice record from the golden Age ( no compression, no correction in the mix...) a record from the Royal Opera House, Covent Garden. Track side 2, La Gioconda: Dance of the hours (I am sure, some of you own it, was remastered from Classic Records, really good job) The very close to perfect alignment I didn't made it totally wrong (that everyone will say."Of course, this is so wrong, it has to sound awful..." Just a few hairs next to it.... Honestly, I think, most have this Situation. Not because you can't do it better, the problem is in general the limited view below cartridge Body, or "the last move" before fixing the screws.... It is not so bad in listening, when you can't compare it with the following alignment, I bet everything I own, nobody will notice it. It is NOT distorted, it is NOT smeared, it is NOT horrible... It is ok, the can't count the rows in the orchestra, but you know what is going on there. You don't "see" the distances from one musician to the next when they play, but you hear different instruments. I think, you know what I mean. Now to the perfect alignment I can hear from the first second a different kind of Soundstage. It is deeper, no limit and it is in a way that the Listener is more or less in a position from one of the recording microphone above the orchestra. Next, the musical flow is different. There are much more tiny nuances. These tiny nuances (or micro detail) is an addition to the main information, but this different. You see the rows in the orchestra (from above), you have an imagination from the musicians to each other. The tones of their instruments have a time shift. It is more like a holographic "Picture". This is not depending on the price of a cartridge. It simply shows that everyone can get more from his Set up when he is able to do it right. And it is possible to rare a cartridge, because these differences from identical cartridge are comparable to sell and buy something new (".. I had this, have that now and it is MUCH better": This can be pure luck, probably the new one was adjusted a bit better by accident...) There are some differences from the Recordings of course, this Set up is made for those which have the full dynamic swing in the last 3 tracks (where other Arms will produce a lot of distortions when not done right) Btw. these pics were made with a FR-64s, a separate distance from Point to Spindle (231,5mm) with a Dennesen Protraktor (very rare, very good) Later I made a controlling with a Phantom II and the own Graham alignment Graham Phantom II Here you see the reason why it is possible to listen with the Graham Arms the most demanding records without a compression, distortion or something similar, it is a serious product. Good Geometry & proper calculated. I hope, these few lines will help the one or the other to understand, analog reproduction is mechanical and some care will give you a better result without spending a fortune. Happy Listening |
Dear Syntax,
I really can't see even one reason for your post.
Your first photo is a paradigm that can not happens. Never!
Your third photo also shows a misalignment. Maybe a slight but true. Any difficulty that arises always, it has to do with the cantilever alignment and not with the stylus. Moreover, the centering of the protractor's needle to the pivot point, is by far the most difficult part. At least, this is what I want to believe. It is so obviously basic & easy to put the stylus into the hole, that about your third photo, I prefer to believe that you take a shot from some strange corner that can cheat the eye. The point of discussion is the prefered alignment, together with the accuracy of the protractor. The skill of the user to follow the offered precision is irrelevant. I'll take your examples as were about the difficulty for a successfully precise alignment that offered to the user by the Dennesen, in contrast with the more easy UNI-Protractor. |
Dear Geoch: IMHO Syntax is a marketing manager with a way different knowledge-ignorance level that many of us.
I agree with you and I can add:
Baerwald and Löfgren B approaches differ only in the overhang distance ( that changed the PTS distance with the same EL and offset angle. ), this overhang difference is around 0.4mm that's a lot longer than the Syntax sample/pictures ( as always great photos. ). Both set up geometry approaches are good ones with in theory a little different kind of trade-offs.
Even if everything is " perfect " and the cantilever aligned, re-set of SRA/Azymuth set up, PTS distance, etc, etc. all these we did it in static status when the cartridge stylus hit the LP on playback all we know what happen ( we already discussed in this thread. ) through the imperfect LP medium.
How this Syntax could hear any difference ( if any. ) in quality performance that he can attest was because the cartridge stylus position changed 0.1 mm?, IMHO and with all respect makes no sense other than commercial corruption.
I think that a good product like this protractor does not needs this kind of " help ".
As you said, the protractor makes things more easy and this sole characteristic is important.
Regards and enjoy the music,
Raul. |
Syntax a Marketing Manager? - I thought he fights against Marketing?
always learning new insights...
Best & Fun Only - Thuchan |
Syntax, I agree with Geoch and Raul.
I do not see the point with your posting.
Anyone with very little skill can position a stylus onto a point, so this kind of misalignment would be rare.
Nobody cares about the dennesen tractor misalignmnet vs correct alignment, unless you are doing a vaild comparison against the Uni Tractor.
After all, this is what the thread is about. |
Dear Geoch, you state:
"the skill of the user to follow the offered precision is irrelevant"
what does it mean? As most of us do know and have learned how to align a cart & tonearm combination properly I have seen and heard many times inproper alignments. Having used for many years the Dennessen I know that you need a good time and some patience and also some skills to bring the needle into the hole.
Unfortunately what we are missing in our hobby are learning or training courses on proper alignment. if you don't have a good trainer/coach/friend not only giving you shows or demonstrations (I attended once Mike Fremers demonstration at the High End but this is theory demonstration
only!) and you are not doing it by yourself under supervision using a good tool you will always struggle or feel insecure. Do ask most people out there - not the hardcore guys - how they feel about this.
maybe this is what Synatx tried to demonstrate. 1mm correct or not, if you have the chance to match it exactely why not going for this?
Best & Fun Only - Thuchan
|
Hi,
these pictures are only an example. I did choose the Dennesen with that "hole" to show, that being not spot on will have sonic differences. That's all.
Me a marketing manager? I am afraid, I have a different profession.
Can't hear a difference with the shown set up?
Well, when you can't or think, there are none, it's time for an upgrade.
I made these pics because I heard the differences.
And I made this thread NOT to support the UNIprotraktor, I made it to show every reader, that even close to the right point (or line or whatever) can have good sonic results, but it can be done better.
The UNIprotraktor will go its own way. |
Dear Thuckan, whats the use of the greatest protactor if one can not manage to take advantage of the offered precision?
The improper alignments that you have seen and heard, were due to wrong calculations or average protractor's quality. But if they were arised by the clumsiness of user, well, not only it is irrelevant to this thread, but I think that can also humiliate the demonstrator especially if he is one of the hardcore guys. If the user can not manipulate his fingers and his eyes, how can we speak about hearing faint sonic changes, since this presupposes the mental calm and a certain degree of manipulation of our nerves?
Can you please explain to me what the third photo is were about? Is this a demonstration of a great alignment? |
I'm not the one who is tolerant for this last o.1mm !
I can not imagine someone to spend his money on great TT/arm/cart, when at the same time he is carelessly putting the needle just close to the protractor's hole. It is always about to make the best with what we have. We tend to waste our energy by giving our greatest effort on the most anal alignment we can get, but unfortunately our protractors have limited precision and this is where the success ends. But when we watching the opposit happening, it is at least dissapointing. It is not about how experienced is the user. Once the setted alignment is verified as average by the protractor, when you can see the misalignment by your naked eye, you just don't proceed with a listening session until the results become satisfied. No excuses for newbies. Ιt is a matter of respect to your hobby & your cartridge. |
Hi Dertonarm, you mentioned in your thread above;
"Tonight I will introduce the UNI-scope here on Audiogon.
A superior option to magnify the cartridge's stylus on template by 20 - 200x with a special USB-microscope + macro-cold light + PC/MAC-view, photo storage and measurement option."
"Including plug'n'play software for PC-Windows, MAC OS-X and Linux."
"Furthermore ideal to judge wear or possible damage of stylus."
Did you post? |
This Syntax is obviously a worthtless marketing manager;
he used the wrong protractor for his PR.
Regards, |
Hi Dev, not yet. Delayed by "real world business commitments" which consumed all my time ...;-) .... hope I can list it tonight.
Cheers,
D. |
Geoch says:
Dear Thuchan, whats the use of the greatest protactor if one can not manage to take advantage of the offered precision?
I would agree.
I have been following this thread after having my attention drawn to it by a client (who enjoys the "interplay") and was perhaps thinking of purchasing one, and asked my views.
My response was that there are a few issues raised which are quite serious (in the sense that any hifi issues are serious compared with world events).
Having been a former tonearm manufacturer, out of hifi for a good few years, I am surprised at the amount of woolly thinking still surrounding the whole issue of turntable set up. In this I include Dertonarm who puts himself forward as as a setup guru. It seems that here is still money to be made from people who are not aware of the issues surrounding setup.
So, I have a number of issues:
1. Reading the thread, I take issue with Dertonarm on his analysis of SME geometry and also on Antiskate. He is plain wrong on the SME, and vague on antiskate, and that makes me wonder how pertinent are his analyses of geometry. He is vague on the issues regarding 12" versus 9" arms and why this should make a difference. And why old full length records should be different from new full length ones.
2. He is unclear on the geometry issues. They are simple and have been known for years:
a. With a given minimum and maximum recorded radius and a given effective length, there is
b. a mounting distance (and therefore overhang (or vice versa if you like)) and a cartridge offset angle, which give either: a tracking error such that there is a minimum distortion at the outer, middle and inner radii(Lofgren A/Baerwald); or minimum average distortion across the record (Lofgren B).
In both cases, it depends on a given weightings for tracking error. Equally, there are other weightings one may care to apply to the tracking error. It appears that Dertonarm advocates a weighting that favours the inner third, but doesn't tell us the weighting he applies to the Lofgren equations (which give, as a starting point, the ways to minimise tracking error as opposed to distortion).
If he did so, we could all set parameters for any arm, and any record, following his recommendations.
3. I am concerned that there is a tendency to look at mounting distance accuracy and give numbers for this, without a similar figure for angular accuracy. It only takes a moment to realise that a mounting distance accurate to say 0.5mm is only as good as an equal accuracy in offset alignment. As someone who has experience in this area, I know that it is extremely difficult to hold accuracy to within 0.1 mm by eye, but a difference of a similar amount in offset, ie a misalignment 0.1mm either side of the optimum position for the stylus will give similar errors.
I would maintain that it is far more difficult to set offset to this accuracy than overhang. This is why no one gives figures for the accuracy of offset using their jigs (but, of course, they always seem to be accurate to 0.01mm in mounting distance using a digital readout...or whatever). This is also why the accuracy of overhang setting is at the mercy of offset. Any error in offset should have a correction in overhang. If your offset is wrong, your precisely set overhang/mounting distance is wrong too: albeit precisely wrong. Your mounting distance, with its error, whatever it is, say 0.5mm, might be accurate to 0.1mm, or 0.01mm, but it is still an error of 0.5mm...
To put it into perspective, if you happen to set your cartridge such that the stylus is 0.5 degrees off axis, that translates as the stylus being around only 0.08mm off to one side from where it should be. Half a degree can make a big difference - try it out in the VE spreadsheets. To get within 0.2 degrees would be better, but that means reliably detecting a misalignment of 0.03mm (0.0012")!
Then you have to consider if that is actually a good idea if you don't know how accurately your stylus is mounted on the cantilever, or how accurately the cantilever is suspended. If, as I have seen mentioned, cartridges are made with errors of a degree in these parameters, then where does that leave you?
Then there is also the small matter of the the angle of the cantilever when the platter is at rest compared to when it is revolving. If you can see a difference, it is at least half a degree out.
Then, if you are using effective length as an input parameter, VTF affects it (eg O.1mm from 0 VTF, which is where stylus position is gauged with the cartridge off the arm. Or again, the play in the mounting of the cartridge, which could cause errors of 1 degree, and 0.5mm.
The whole thing is a rat's nest of interdependent variables which, I suppose, keeps the online community, such as yourselves, well occupied!
Personally, this is why I prefer two point protractors. At least if your set-up is off from what you thought it was, (mounting distance, effective length, etc), you have a chance to notice the fact at the second point,
And if your cartridge/stylus is aligned correctly on both (that is, really aligned not wishfully "aligned"), you will be very close, irrespective of mounting distance, as the nulls are not dependent on that parameter if the cartridge has slots; or on effective length, if the mounting distance can be adjusted to suit; and, should an alignment different to the maker's be desired, the cartridge can twist a little,
4. I also have other issues with the marketing of the Uni-protractor.
The first, obviously, is who is Dertonarm? A person happy for people to take his word anonymously, make statements anonymously, and do a marketing exercise anonymously. Of course, presumably there are people who know him (as D, or Daniel? or Axel or what?) but for the rest of us he is just an anonymous person with no history. Does he have a shop? Is he simply giving a sales pitch? I don't hold with that.
I see that there are modifications, or extras, in the pipeline, presumably to sort failings in the original design. Given the fact that they are following close on the heels of the original, I presume their design was ongoing as the original was introduced, and are available as free upgrades to sort a failing in the original design, otherwise why wait to introduce a "better" device to set mounting distance or a special "azimuth template"? Why not include it in the original package? Or wait and introduce it later?
It begs the question of whether it was a design not properly thought through in the first instance, or, cynical marketing, unless upgrades are free as per car recalls for faulty parts.
It appears he has sold some 40 of these protractors. Its prime function is to set mounting distance. Anyone who can do some basic arithmetic can buy a digital caliper for 10 euros and set their arm mounting distance to within 0.1mm (if they can be bothered to be conscientious enough, which applies to any set up - you can spend an hour, or you can spend five minutes setting up your arm and cartridge; you can use a two point protractor or a fancy Uni-P or Feickert; but if it is a shit set-up, it's still a shit set-up...
Sorry for the length of this post, but if you've made it to here, well done, and hopefully you've got something to think about.
Comments welcome...
Regards,
John |
John,
Could you please expand on your comment regarding the SME V arm? I have one of these and currently use the two-point MintLP protractor. What is faulty about Dertonarm's statements about the SME geometry? Thanks. |
John G,
A few comments...
#1) I have nothing to say on his or your comments on antiskate and SME. I have seen no vagueness of analysis on 12" vs 9". Given what you say later in your post, it is pretty obvious you have a simple explanation (but you did not give your analysis either). I think if it is obvious to you, it may also be obvious to others. It is to me. If you have additional complex analysis of the differences, please share. I think 'analysis' of 'why' old full-length records should have different innermost and outermost grooves is kind of a moot point. They are different (at least mine are). If one has looked at enough records, one may notice patterns among periods, recording companies, cutters, etc. I think that noting the difference and applying math to it to achieve better set up where desirable is easy, and I think that is what he has done. Standard geometry using standard assumptions does not always produce lowest possible distortion except in the case when the record has the same dimensions as the standard assumptions AND one does not prioritize low distortion in one part of the record over another.
#2) I don't find him unclear on geometry issues at all. As far as I can tell, he has stipulated everything you have written. He shouldn't have to as the math does not change. He mentioned in these fora, that given his parameters and listening preferences, he had found a better way (than the manufacturer's stated geometry, or standard Baerwald geometry using manufacturer's stated effective length) to set up a particular tonearm. Others pestered him on it, and he politely refused to be harassed. The effort spent by one person in particular on harassing him about this subject could fill a small magazine issue, and may have closed down two threads. I thought it would do this thread in, but he left some hints about it, and I did some analysis to figure out Dertonarm's 'geometry' including the "weightings" you speak about. It took me about 10mins to come up with it. If you did not read the analysis above, the short version is that assumes IEC records, and is basically a cross between Stevenson's 'tilt' and Lofgren A's curve shape. It achieves lower average distortion in the place where he wants to achieve lower distortion (second half of the record), and achieves sharply lower average distortion in the last 10% of the record for long records than either of the standard setups, especially when those tonearms/carts have been set up for DIN. It is, as he has stated, entirely a matter of choice based on his record selection and his priorities on where on the record he wants to hear his distortion (or lack of it). It is decidedly not 'new math'.
#3) I think all of us, including the dastardly Dertonarm, get that minute changes and ball-busting accuracy requirements for one or two of the parameters will necessitate the same accuracy requirements for ALL the geometric inputs (though inner-most groove by its very nature must have some flexibility because one does not newly align (or set up a new headshell) for every particular length). If you read his posting history, it is blatantly obvious he shares your opinion. On the other hand, bad implementation of offset angle is bad - on any geometry on any tonearm.
As an aside, as far as I can tell, the supplied lengths and angle for your signature tonearm don't match the null points noted in the manual. Not having seen the supplied protractor, I can only presume it was in fact like a jig so that people could set their cart perfectly straight without deviating from appropriate offset angle, and then the overhang would fall into place shown on the protractor. Using the accuracy as stated, one would not have come up with the same null points as you did, which means that anyone using a protractor other than yours would have been off Baerwald by a decent bit, even if they had managed to get the offset angle and mounting distance perfect.
#4) If you read his posting history, you can glean a fair bit of his history (who he is, what he has done, etc). A little bit of digging and you can find more. I don't know him personally but have discovered a little on these threads and more elsewhere. Without doing the digging on you, one would not know who you are either. As to the protractor, other people challenged him on the subject, and rather than complain about being attacked, he made it. He is now offering it out. Is it more expensive than a laminated piece of cardboard? Yes. Is it for everyone or is necessary for achieving good sound? No. But neither is a gold-plated tonearm with diamonds on the headshell.
If you have but one or two tonearms, it may not be for you. If you have a half dozen, it may be cheaper than buying a half dozen protractors specifically designed for those half dozen arms. One could obviously make one's own 'mirrored' protractor using a CAD program, printing on clear plastic and mounting that on cardboard with some aluminum foil in between. But that is beyond most people who don't have CAD design experience. I don't have anything better than SketchUp, which is kind of a PITA to use, and I figure that if I don't like mine, I can probably sell it and not lose too much money on it. And in the meantime, I will have a cheaper tonearm-specific protractor for my more than half-dozen arms than I would if I bought just one. And I will have a universal protractor which will work on other tonearms. And I expect that it will be easy to use so that my conscientious set up will take less time and back pain than it would otherwise. I know nothing of the extra goodies/modifications yet other than what he has written, so cannot comment. You could send him an email and ask him yourself. |
John Gordon , you are new to Audiogon. This is your first thread´s reply which is ok. I am wondering about your conclusions which run on a string, IMHO the only intention to undermine Dertonarm`s reputation. I am not going into detail, T_Bone did in a very persuasive way. If you are really an expert on tonearm design you may have a different approach to this topic as you used it.
Best & Fun Only
Thuchan |
|
Downunder
Yes - I am that unmasked man...
J |
Peter: Earlier in the thread you asked a question regarding SME and arc protractors (3.11.11) Surely with arms like these the crucial thing is to determine the effective length as accurately as possible and then set the appropriate pivot-to-spindle distance, again as accurately as possible." Thom then goes on to miss the point and talk about another issue which fact you then gently draw to his attention. Then Dertonarm says: But back to the SME V, which was when introduced anticipated like no other tonearm ever before or ever after.
The SME V is unique in the sense that it's offset and effective length (at least its designers thought so and intended it to be that way...) are fixed and pre-determined. Problem is, that SME Ltd. took for granted that each and every cartridge manufacturer would strictly follow IEC standards regarding stylus-mounting slots distance. Which of course they did not.
Now there is the legendary SME slide base to allow sliding the whole tonearm back and forth. That way the arm kind of "moves to the wanted alignment spot".
In theory....
The fact that the fixed offset angle of the fixed headshell isn't really a feature which eases things in any way did not really appeal to the SME engineers in their strive for setting the technical frontier in tonearm design." Now, apart from the tone (hopefully humorously intended, but easily taken as arrogant and disrespectful) and the assumptions regarding the motivation for the design, there are two very elementary errors: the first is assuming that the SME has a fixed offset and fixed effective length. It has a nominal offset, and nominal effective length. The misunderstanding here arises from conflating cartridge offset angle and headshell angle. In the SME the headshell angle is fixed and decided by the geometry selected by the designer (Baerwald/LofgrenA IEC). Once this is decided, another dimension follows, namely, linear offset (LO), and this is then a constant for the hardware and given by the effective length times the sine of the cartridge offset angle. When a cartridge is fitted it retains the headshell angle (within the limits of the mounting hole clearances), and consequently the linear offset remains unchanged. So if you mount a cartridge with say a 12mm mounting hole to Stylus (MH2S) as opposed to one of 9mm MH2S the effective length increases and the cartridge offset decreases, and with a 6mm MH2S the opposite occurs. There is no twisting cartridges unless there is a misalignment within the cartridge (can of worms left unopened...). Only the base needs to be adjusted to supply the correct mounting distance (and therefore overhang) to align the two nulls. I hope I have explained this well enough. It is something over which even some well respected tonearm designers appear to get confused...try drawing it out on paper. The second error is assuming that any standard for cartridge mounting hole to stylus distance was implicit in the design. In fact, the opposite could be argued, as this parameter is only relevant in setting up an SME if you use an arc protractor, which is arguably not as universal as a two point, (which can be used with any arm and cartridge) and with the SME is easy to use, owing to its clever sliding base. To use an arc with the SME V you need to measure the effective length accurately (or as accurately as you can) then obtain and adjust the mounting distance until ideally the two nulls are squared off as per Baerwald/LofgrenA IEC. . Dertonarm says "The SME V is a super strict 9"/Baerwald IEC-standard tonearm. The "super strict" 9"V and the V12 share the same geometry, ie Baerwald/LofgrenA IEC. TPerhaps the V-12 is super strict 12". (I believe the 300 series are actually DIN as opposed to IEC, which should actually appeal to DerTonarm, as he, correctly, in my view, advocates a more general alignment to allow for inner radii less than the IEC standard) You can't really align him a Loefgren or Stevenson curve with good results." Lofgren B IEC is simply a matter of sliding the base slightly forward - no fiddling with the cartridge screws. Dertonarm said in another thread re SME (ironically given the 300 alignment mentioned above) "The SME 300 series is one of the very few tonearms which does come with a kind of "fixed" geometry in ALL parameters. Given its unability to adjust offset, overhang (we can just move the base - which we shouldn't ... - NOT the cartridge ) and effective length, it surely is a fairly unique sample...
...SME took for granted all industry standards of its day (early 1980ies) and said:
"well, if all cartridge designers do obey to and follow the standards given and if all LPs are cut following the new IEC standard, then evrything will be perfect with our new tonearm - it will be the "best tonearm in the world"............"
But the world is an imperfect one and many people do want to go their own ways.
The new SME surely was the LEAST UNIVERSAL tonearm ever designed .......
It is for sure the one tonearm which gives almost no possibilities to adjust to specific cartridge needs or to different arcs." I make no claims for SME universality, but all the above is simply laughable, or misleading. So, Peter, it looks to me like you are setting up the SME correctly. The only issue is that you should use Baerwald/LofgrenA IEC nulls. If you mount your cartridge as accurately as you can in the headshell, then align to the nulls you should be very close. If you have measured your actual effective length, and thereby obtained a mounting distance for the alignment, you can use an arc to check. Hope all this is of use. John |
Thank you for the clear explanation John. I did supply Yip at Mint with the stylus to mounting hole (MH2S) distance which he used to make the (unique to my arm/cartridge combo) arc-type protractor. The stylus aligns precisely (by 10X loupe standards) at all points of the arc. At the two null points, I adjusted very, very slightly the rotation of the cartridge in the headshell to align with the guide lines at those points. I presume that my MintLP Tractor follows Baerwald/LofgrenA IEC nulls, though I did not know enough to confirm this with Yip when I ordered it. I may email him. Thanks. |
Dear Geoch,
I know there are still some "fossile guys" out there believing they ( and so everyone) is able to aligne a tonearm by just a small piece of paper. They tell their customers or friends precise alignment is not as important as buying the right tonearm or product. Their customers are usually not very eager learning about proper alignment and its exacetly what they like to hear from 'those gurus' . " you bought the right product, don't worry at all". As long as the (analogue) world will allow herds of followers to believe in such crude philosophies we should not bother about the existance of audio afficinados never being able to distinct good from bad sound.
The (analogue) world is like it is, some good developers and failed ones.
Mostly the failing guys do have a motivation to define the world and tell the succesful developers what they seem to have done in a wrong way.
believe me, I do know producers of tonearms and even turntables who do understand the theoretical implications of proper alignment but they do not really care about it. showing images of inproper alignment may help for a better understanding of the topic - that's all.
best & fun only - Thuchan |
John,
In my case, in my #2 paragraph, I reversed DIN and IEC (Dert geometry assumes DIN records, not IEC; and his alignment for the FR-64S creates lower average tracking than using mfr specs for Lofgren A IEC). I will blame it on my lack of morning coffee :^) but I've reversed them before and I am sure I will again.
Thanks for the SME bit. I need some time (and coffee) this morning to wrap my head around one aspect of what you said. May revert. |
T Bone From your all your posts on this thread, you have obviously thought all this through, and I appreciate your comments. First let me say I ploughed through the thread prior to posting and read all the arguments with all their points, both relevant and off the wall. I also looked at related threads. I don't have an axe to grind, other than the one called clarity, and I am the first to admit I might not be as clear as I could be at times. To take your points: 1. I have seen no vagueness of analysis on 12" versus 9". Basically he doesn't say why he considers Baerwald/LofgrenA IEC a 9" as opposed to a 12" alignment - the nulls are the same - and confuses the issue with the comments regarding record radii by talking about old records. I'm not saying he's wrong, just that the two things then get connected disproportionately. What I was asking was if he saw a difference between old and new records with full sides - is that a factor. I have old records with very long run out groove, and new ones with the opposite. What he should have been clear about at the beginning was that the issue is primarily about where the minimum radii are in any particular collection and what each person wants to do about it. That is as you say, step one, and I agree. Average out the radii in some way, or use a deck as Nandric wittily suggested, with four arms set for different minima, or whatever. In which case there are no standards, but different nulls and you get a protractor to suit each. You said Standard geometry using standard assumptions does not always produce lowest possible distortion except in the case when the record has the same dimensions as the standard assumptions AND one does not prioritize low distortion in one part of the record over another. I don't disagree. I just asked that he should have been specific rather than vague. 2. In other words, is he just saying: "use a minimum radius of 55mm", (say, or 57 or whatever), or is he effectively saying: "I played around with the spreadsheet and found nulls which work best with both DIN and IEC", or is he saying "I have a theory which says that the existing weightings are inappropriate because there is D% more distortion due the added effects of X and Y and Z, and here is what I think the weighting should be.to compensate - use this to insert into the Lofgren equations to calculate the best alignment for your record collection". That to me, is being vague, or obtuse, deliberately or not. I'm not looking for "new math", just asking for clarity regarding the existing old math. I have looked through the thread and admire your persistence in bringing some sort of sense to the scene, and I take all your points regarding Darkling Dert's alignment being the way it is. I don't disagree with him, or say he is wrong in what he is taking as his parameters and objectives, but until your intervention it appears that he wasn't up for clarifying things. Presumably, he had reasons for that, personal, commercial, legal "foral", who knows. 3. You said I think all of us, including the dastardly Dertonarm, get that minute changes and ball-busting accuracy requirements for one or two of the parameters will necessitate the same accuracy requirements for ALL the geometric inputs (though inner-most groove by its very nature must have some flexibility because one does not newly align (or set up a new headshell) for every particular length). I wasn't talking about being so anal as to change alignment for every record, nor saying that DerT wasn't concerned with accuracy, but drawing attention to the fact that he didn't share any measure of that concern in terms of how accurate was his offset angle adjustment method. As you well know, if the angle is off by half a degree, never mind more, all that precision will leave your alignment different from what was intended, and generally not in a nice way. You said: As an aside, as far as I can tell, the supplied lengths and angle for your signature tonearm don't match the null points noted in the manual. The null points for all my RP1 arms as I recall, were 63.5 and 119.5. with a minimum radii of 58/146 - basically Baerwald Din, rather than IEC, as I had more records with that characteristic, and it seemed a good option - in that regard I concur with DerT. I think he is correct. And I would agree that a different alignment approach can pay dividends. Not having seen the supplied protractor, I can only presume it was in fact like a jig so that people could set their cart perfectly straight without deviating from appropriate offset angle, and then the overhang would fall into place shown on the protractor. I don't get this, T Bone. No jig was supplied. The protractor was a two point, and the effective length was a nominal 230mm, the offset, a nominal 23.5degrees, with a linear offset of 91.5. Mounting distance was therefore variable as it would depend on the effective length with cartridge (see SME comments to Peterayer above) Using the accuracy as stated, one would not have come up with the same null points as you did, which means that anyone using a protractor other than yours would have been off Baerwald by a decent bit, even if they had managed to get the offset angle and mounting distance perfect. Could you be more specific? I'd have thought that would be more applicable to arc protractors... as long as there is play in the cartridge mount you can get a Baerwald IEC or Lofgren without any problem -just adjust angle and mounting distance as necessary. You'd need a two point protractor, though. 4. I don't know Dertonarm, and perhaps I could dig up some info on him, if I had to (the internet is a wonderful thing, but time consuming). My point was that I don't think I should have to. If I was selling something, I'd be happy for people to know who I was, and where I was - it's not an issue for me - although perhaps I'm just a bit behind the times and it's more acceptable now, in a forum, on ebay etc. Anyway, you knew exactly who I was, without any digging, and, by now, anyone else who wishes will know a great deal. As to the protractor, other people challenged him on the subject, and rather than complain about being attacked, he made it. He is now offering it out. Good for him, I hope he makes his money back, but he isn't doing anything different from a host of others who try their luck at the hifi business. Is it more expensive than a laminated piece of cardboard? Yes. Is it for everyone or is necessary for achieving good sound? No. But neither is a gold-plated tonearm with diamonds on the headshell. A slightly cheap shot - I don't know you and, with you, I have no beef, T Bone, but perhaps I deserve it. If I have been a bit too critical in some areas and if I've caused offence, I apologise, But reading the thread, there were some obvious things that needed to be said. And I agree that gold plate and diamonds aren't obligatory, however, you may have given our man, Diamante Dert, an idea for a more limited edition... |
Thuchan
If Dertonarm has a reputation (whatever it may be and for whatever reason) hopefully he deserves it. That doesn't mean one should accept everything he says is correct when it patently is not, and is not a matter of opinion.
I have responded to T Bone - see above.
Regarding opinions, I may have have been a bit too straightforward in expressing some of mine, and for any offence given, I apologise. But there is no point in ignoring mistakes - I've certainly made enough of those in my life, and was the better for having them pointed out to me...
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John Gordon,
at no time I said I accept everything what Dertonarm says. If you look into the many threads you are now stating from you should know this. Also discussing controversial I regard as absolutely essential, not only in this thread. I have no clue what or who is driving you.
If you do know Dertonarm from the threads and you obviously studied many, especially the threads he participated in, you may know that Dertonarm is a critical contender too but more on the content side. If you have an honest agenda you will enjoy it discussing with him, not necessarily sharing all his opinions.
best & fun only - Thuchan
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John,
Thank you for taking my comments with good humor and responding politely. I took your original comments as just another shot at Dertonarm. While we are all full of ourselves sometimes (and full of sh-t other times) - myself not the least guilty - I have not found a huge amount of fault in D's intellectual approach to things. I have found more fault in the intellectual rigor, or lack thereof, of those who have attacked him in this thread (and others).
1) As to his comment on Baerwald IEC being a '9" standard', I read a different meaning into his comment - I thought it was a throwaway - a comment on fact rather than a normative statement. I will re-read it.
2) As to his reasons for recommending that one alignment (and keep in mind, it is, as far as I know, only for one particular tonearm), he has stated in this thread and others that for his longer (i.e. lower value inner groove radius) records, which are classical and have crescendos/climaxes near the end of the record, given his priorities it makes sense to have the lowest tracking distortion in the second half. I don't disagree on that point. Tracking distortion is, unfortunately, usually calculated assuming a constant velocity of signal (10cm/sec at 1000Hz for mono as per DIN 45537 (1962) and 8cm/sec for stereophonic some 20yrs later). Crescendos have a wide variety of frequencies, including timpani and bass drums, which are far lower than 1000Hz and this may therefore increase peak velocity load on the cantilever/stylus/cart motor in the inner grooves, making the practical use of a constant peak velocity across the record less relevant. If this were a universal truth about music and its placement on the record, it might behoove someone to come up with some 'new math' (neither Baerwald nor Lofgren's equations are set up to be able to accept that kind of 'new' assumption without some serious re-jiggering) to help Baerwald/Lofgren 'weight' the tracking distortion differently, and therefore come up with both different null points. But it is not, and there are enough people who are religious about Baerwald being "best" without thinking about details like this that it is a lost cause.
It is my understanding that Darkling Dert has also said something about your third point (i.e. there is D% more distortion because of factors X, Y, & Z). It is (and I paraphrase here, and I may have misunderstood) that the relative pressures on a cantilever/etc are more violent in the 60mm radius area because the groove modulations are a greater percentage of the radius than they are at 140mm. This I am still thinking about. There is a Japanese guy who has done a whole bunch of research into the finer nuances of the physics of grooves, tonearms, angles, and distortions, but I am still working my way through his stuff. I am sure I don't understand the physics here. At first glance, I would have said a constant 1000Hz signal of amplitude X across the whole record will have the same relative movement on outer groove as inner groove as far as the cantilever is concerned (when moving against the effective mass/inertia of the cart/arm), but given different relative velocity of the stylus through the groove, it may not be the case. I guess it is also possible that stylus aspect change with respect to the groove wall could affect tracking distortion dynamically, but I'm working on that - and in any case, in any practical sense, it still goes back to the earlier point about records and priorities.
3) My point here was that we all get the importance of being as exact as possible in all parameters. It is mathematically so. We can therefore stipulate it. None of us are perfect, but we all try. My comment about the RP1 parameters being inexact was simply me being pedantic and small-minded given the emphasis on exactitude of all parameters. I cannot get 230/17/23.5 on DIN (or 58/146) as shown in the manual to match 63.6/119.5 (also shown in the manual). Something has to give. Your point about 'just adjust angle and mounting distance as necessary' is EXACTLY right and appropriate given the imperfections we each bring to the table when we mount a tonearm/cart, but that is the art, not the science (and most of the critiques of Dertonarm's ideas and protractor on this thread are on the science, not the art, of tonearm setup, and his product I would think is specifically addressing ease of getting the art right - because the science is gotten right by anyone who gets the algebra right).
4) I am not sure that people should need to post their resume of qualifications before coming up with a protractor and marketing it. As you pointed out, the math has been known for decades.
Your first post here implicitly claimed an expertise that you did not pre-qualify, and I did not know who you were without digging, but you so kindly gave your name in your moniker so I went on the internet (which is, as you note, a wonderful thing) and linked your name to a tonearm, which I had heard of and seen before.
In any case, if one has to have a long and public record of producing a good product and supporting it well before one can sell one's product, then nothing would ever get done. How does anyone ever get a first product sold?
I must apologize for the bit about the gold and diamonds. Indeed it was something of a cheap shot, but likewise, you didn't know Dertonarm either. But your implication was that a 10-euro digital caliper and a regular two-point protractor would get the job done just as well for less money. I may end up disagreeing (mine has not arrived yet) after I use it (especially given that I have a few different arms at hand now) but implied in your complaint was that his object was too much money, or an unnecessary expense.
And perhaps Diamante Dert will indeed be able to come up with a Bling-Tractor® (but I, for one, won't be buying it).
I am, however, still noodling on some of the aspects of the SME issue as you brought them up. Without having drawn it out yet, my feeling is that when you change mounting distance because of shorter MH2S than assumed, you have also minutely changed required cartridge mounting angle (because your change in mounting distance is happening on a different vector, and you are therefore changing EL of the physical item (which in my very limited noodling so far, makes me think it should require a (very slightly) different offset angle). I don't know enough about SME tonearms' implicit assumptions to disagree with anyone on what the designers intended, and in any case, my experience so far is that most tonearms have enough play in the mounting parameters that one can be minutely flexible if one wants, even if the design is not meant to accommodate 'play.' |
Dear T_bone, just a short side-kick regarding the SME V.....
The offset angle of the headshell is pre-determined - sorry, not my idea, but the idea of the SME-deisgner(s). Given the fact that the mounting hole in the SME V is not really intended to allow anything like a "cartridge offset angle" (which in tonearm geometry not really exists at all - other as by wishful thinking), one can assume that it's designer did so by good reason.
As this mounting hole is (to the regret of many of it's owners past and present - including me ..) not really an elongated one either, the effective length is - at least in theory and designer's intention - pre-determined as well.
Setting the "cartridge offset angle" other than the offset angle of the tonearm's headshell does produce an additional break-down torque in the tonearm's static model - i.e. an additional force vector.
This is a plain mechanical fact - thanks to Isaac N. ...;-) ....
That additional break-down torque does of course influence the skating force.
Now is the SME V designed and constructed strictly following Löfgren A IEC (Baerwald)?
According to it's designer's it is.
According to it's technical parameters it is too.
Can one adapt the SME V to different alignments by moving its slide carriage? It was not intended to adapt to different alignments, but to different position of stylus relative to the mounting hole of the SME V.
The moving of the SME carriage does alter P2S and adapt's the effective length to different distances - in cartridges - between the mounting hole and the stylus.
Thus being able to retain the original Löfgren A IEC alignment is was calculated to.
Best,
D. |
Thanks Peter
Glad you found it clearly stated
J
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