Dear All, I do agree with Raul on most of what he said in his last post.
However - let me put it in a few "axioms":
1) offset, overhang and effective length do relate to each other and CAN be CHANGED WITHOUT changing the PIVOT-BEARING DISTANCE. Offset, overhang and effective length do change when you align to a different arc-calculation (say - change from Baerwald to Loefgren).
2) If you change the pivot-bearing distance you change the WHOLE GEOMETRY of the given tonearm.
3) you get the very best results with the recommended pivot-bearing (= mounting distance as specified by the manufacturer, because the whole geometry of the given tonearm builds on that one parameter.
4) whether you choose Loefgren, Bauer, Baerwald, Stevenson or whatever calculation for the alignment of the stylus (and these calculations are onyl aiming at the position of the stylus - not at the position of the tonearm !!) is INDEPENDENT from the geometry of the tonearm itself. These alignments can all be done at the headshell alone without moving the base (and thus the pivot-bearing distance). And they should be done without moving the base because that way you can be sure that the basic geometry of your given tonearm is as specified by the manufacturer.
I think we must clearly put a line here between the geometry of the tonearm WITHOUT a cartridge. This is the basic geometry of teh tonearm itself.
Then there is teh geometry of the stylus in a given tonearm. This is step 2. Here we have the option to align to whatever calculation does fit our needs best (for instance more modern pressings with long run-out-grooves or pressings from the early 1960ies with the inner grooves running close to the label - these need different alignments - one rather Baerwald - one rather IEC). Here we lay the position of the 2 zero-error points and the maxima and minima derivation. This 2nd alignment does have variations in the offset, overhang and effective length (not much, but some) - but NOT in the pivot-bearing (mounting) distance. |
I'm wrong, what we are doing is an additional arm wand of 2cm over 12", that's all.
Raul. |
Hi, just a little aside from behind the curtain as it were.
SME in their misguided wisdom using the "ICE-standard" (that strangely exists for LP manufacturing at al, BUT not cart ALIGNMENTS, correct me if I'm wrong ) for their alignment happen to use Baerwald, hallo!
Now Baerwald is what most everybody and his uncle is using these days... and is constantly being referred to in this here circle, very good.
The other item that might shine some light on this pivot to pin distance issue, and SME's disregard for such importance is: The SME V (in fact all 300 series) are based on a mounting hole to stylus tip distance of 9.52 mm or better 3/8". Therefore 233.15mm stylus-to-pivot distance, and a 23.6350 offset angle.
Most carts I've seen/worked with are ball-park, give or take 1/10 of a millimetre. This means that the post is move by about that amount to correct for overhang for that specific cart. A difference in VTF alone will change this distance by some 0.01 mm.
Nobody seems to take note here, that when a hole of some dimension about 32 mm is drilled in a plinth to take a fixed pin/pivot arm arrangement, that 1/10 mm or even less is simply within tolerance.
Unless this is done in a tool shop with a highly accurate machining set-up.
So whilst I DO agree with the importance of it all, I surely disagree to get complete anal about this. Reality of arm fitment is most probably a lot worse than <0.1 mm.
Now I feel so much better :-)
Greetings,
Axel |
Dear Axel: Certainly the analog imperfect world " permit " that the people take decisions that are more oriented in " feelings " than in scientific care like the tonearm/cartridge set-up. Even those 0.1mm affect/provoke changes/distortions that are added at the whole audio system ones.
This kind of " behavior " unfortunately happen in every single link in the audio chain, sometimes by careless and sometimes by low know-how.
What is important to note is that many of those distortions are in our each one " hands " to make it lower if we take care on it not only in the whole system set-up but in the whole audio item system selection.
There are many many different subjects/factors that are "under " our each one control but even we don't know it.
Our each one audio learning curve is a " long road to home " journey where maybe the best way to help us is through an open attitude thinking that almost always exist a better " way " to make things to improve/grow-up.
I always try to think that the " best " is for coming.
Regards and enjoy the music.
Raul. |
Dear Axel,
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.
The SME V was a child of its day and was regarded when introduced as the first tonearm which took all (some fairly new...) industry standards for record-cutting and cartridge dimensions serious.
Too serious.
In a biological sense the SME V is the very opposite of evolutionary versatile.
It can not "adjust" to any change in the "enviromental conditions".
With the "right" cartridge, it is a VERY serious tonearm.
But there are so very few "right" cartridges for the SME V around....... |
Dear Raul,
yes, the analog world is an imperfect one and will always be.
I just think that in tose few areas where we do have pure sientific parameters - teh geometry - we should try to use them for the very best results and should follow them as strictly as possible.
There are so many other segments of the analog front-end, where our "feel" and "intuition" is of paramount importance - cartridge, cables, VTA, VTF etc.
Here however, pure geometry is I believe of great help.
This is the reason why I permanently insist on the strict application of the 2 geometrical calculations for the complex tonearm/cartridge topic.
Its the foundation of all which follows in the audio chain.
Making any mistake here, will make it VERY hard - if not impossible - to fix that "bug" ever after. |
Hi Raul,
nice to be able to call you by name, unlike most folk that prefer to hide behind some alias.
All taken in good sprit, the point missed might be, that some folk might leave this here discourse with a major case of 'audiophila nervosa' because their spindle/pivot is out by 5 hundredth of a millimetre.
Figure that out in thousands of an inch if you will, and it might give more of the participant a better feel what tolerances we are talking. Recall it takes 25.4 millimetre to make 1 inch. So now we are talking about 3 or 5 hundredth of a millimetre!
AND we still take care by a good set-up to compensate for this, by making sure of the right amount of overhang at each null-point AND being dead-on 90 deg. It seems to get just a bit 'unreal' to pretend to pursue this hyper-tolerance notion.
Add 0.1 gram (usually 0.4 gram tolerance) variation in VTF, your suspension goes a bit down, your stylus-pivot distance has changed by 0.002 or0.003 at least. Now we 'pretend' get the arm post holes drilled so this is within such tolerance --- please, let's just accept the real world situation, I say.
One last point I want to share: the lateral Azimuth (twisting the cart left or right) when trying to get the CANTILEVER (never mind the cart body) as close to 90 deg. (0 deg to the groove) at the two null-points.
This is some issue with ALL fixed head shell hole arms e.g. SME V, IV, 300 series, Linn..., when a cart's cantilever is not quite in the 'perfect' place related to the mounting screw-(threaded)holes of that cart.
It is than because nigh impossible to get it to 90deg. due to the next to no play (~0.05mm) of the mounting screws in the head shell holes.
So, get a better cart, or file open the holes? Do not drill them open!! This would allow for too much lateral movement of the cart in the head shell. I discourage this of course, but to spend another 2-3k dollars may just make you change you mind on that also.
Greetings,
Axel |
Dear Axel: Yes, I agree we have to accept the real world situation specially when things are out of our control or best effort.
What I mean ( sometimes I can't explain me in the precise way ) is that if we want to improve the quality perfomance of what we have we can do it ( right now ) and with out buying new audio items but only reexamine the set-up on each single ( big or tiny ) link in the audio chain, almost always ( when we do that ) we can find " land " to improve even with simple things like cleaning ( time to time ) the input/output connectors ( yes, IMHO these RCA/XLR connectors are a link in the audio chain. ) on the audio system. Anyway what I'm trying to say is that if we want to have better quality performance in our today audio system the best ( not the only ) way to go is try to put at minimum the whole audio system distortions ( any ).
The tonearm/cartridge set-up is a great example where we can put those distortions at minimum if we take care about and if don't here in this single link " things " could goes wrong and against to the " minimum distortion " target and against to be nearer to the recording.
But this is only an exampe and we have to put the same care/know-how in all the audio chain ( even that connectors cleaning exercise permit to lower distortions. ).
+++++ " Making any mistake here, will make it VERY hard - if not impossible - to fix that "bug" ever after. " +++++
well Dertonarm put the " finger where pained " ( IMHO he was a little " cheerful " when he say: very hard to fix after. ): IMHO and I agree with him anything we lost or add in an audio link we lost for ever and there is no way to recovery in the original status and with out adding other distortions/stages.
I posted several times that the free-will " compensation " whole/normal ( even a establisment. ) practice ( audiophiles, dealers, reviewers, etc, ) in audio to achieve a sound reproduction that we like through a selection of audio items to have " synergy " is one and incorrect form to be nearer to the recording ( well this is the target and if your target is different then this words are not for you. ), I say that " compensation " practice put us farest from the recording because trying to fix errors ( distortions ) adding other error/distortions can't IMHO give us the correct one.
We can read in any forum and commercial audio " pro " magazines things like this: " if your system is a little on the bright side then don't use this cartridge ", " if you want a warm sound then use this audio item instead the other ( any ) ".
This kind of attitude preclude ( in some ways ) the opportunity to improve in real manner the quality performance on our audio systems, let me to explain a little about trhough an example:
we buy or borrow a new audio item ( a very well regarded audio item almost a statement product. ) and then we connect/integrate in the audio system and hear it.
Normaly we will hear somethings that we like and somethings that we don't but almost never we try to make changes in the audio system ( everywhere ) to really integrate/set-up the new item where this new item ( statement product ) could really shine/show its overall quality.
We go to what we don't like it with out think that that new audio item quality performance maybe are showing the own audio system " anomalies " that have to fix it.
Then we say: " that product is good but not good enough for my audio system. " with out thinking that that product is a way/tool that can help us.
I remember very clear the Monaco TT review where the reviewer take that incorrect attitude, where he don't go in deep to find how good was that TT ( against the one he own. ) and this I think is an obligation of any reviewer. There are several similar examples.
So we have to reexamine ( the people that whant it. ) what we have with a non-compensation attitude.
IMHO we can't grow-up if we continue with that " compensation " attitude that we take it like false " synergy ".
Speak to try putting distortions at minimum means ( between other things ) try to find neutrality/accuracy elsewhere ( not analytic or cold sound ). I can asure you that when we work in this direction the rewards are enormeous and the music enjoy through our audio systems is so high that you can't imagine till you have it.
Axel the Azymuth subject is a critical one due to our " real world ", not only because the cartridge cantilever many times come off-out of place but the stylus are not perfect centered and at the right angle.
You have to think that all what all the ones that already posted here on the tonearm/cartridge subject " collapse " if we can't make Azymut changes.
IMHO a tonearm that does not permit Azymuth control/changes is an unfinished product, period.
Now, other than put some side-spacers in the headshell what you can do with your SME is to set-up the tonearm main column/rod with a little inclination either side you need: yes, you can do it.
Regards and enjoy the music.
Raul. |
Raul,
you're the man! Couldnt agree more with you.
Note: The Azimuth has to items to it: lateral and vertical Herr Tonearm explained...
Vertical is A OK with a cart like PW in an SME, it allows for some degree of tilting due to it's 3 point mounting plate (must have thought of SME here :-)
If the cantilever it too skew to the cart's body we are in BIG trouble with SME's non slotted design. BUT ONLY is since everyone asked for screw holes in the cart mounting plate!
This then has next to NO adjustment left to 'twist' the cart left or right. If the cart has just the good old lugs with the long bolts and nuts used at the bottom, there is enough play to come right usually, maybe not with the worst though.
It seems the price to pay for a more 'comfortable' cart adjustment...
This is actually was what I found out to be the source distortion. I got it pretty much fixed, but juuuust just with max. twisting to the left as so to align the CANTILEVER, never mind the cart body it mean NOTHING. Look at the cart body --- you can't even notice a difference.
Thank you for caring,
Axel |
Dear friends: IMHO we have to see/take ( everyone ans specially the tonearm builders. ) the tonearm like a " tool " a very precise tool that ( between other important subjects ) can/must give the opportunity to have a near perfect cartridge ( like a whole. ) alignment through its " facilities/infraestructure " .
Some ( fortunately only one or two ) tonearm builders say that they don't compromise the tonearm " rigidity " ( or the like ) for some of that cartridge alignment " facilities ".
I respect their opinions but I disagree with because I think the " source " is the cartridge not the tonearm ( the tonearm is " only " a tool/medium, a very important and critical one no doubt about but the main " star " is the cartridge. ) and IMHO the main target has to be a " perfect " cartridge alignment and from here they and us can do anything they and us want it.
This is my approach: I don't like ( through my experiences ) trade-offs on cartridge alingnment due to tonearm limitations, I prefer a trade-off in the tonearm device, at the end of the day nothing is perfect and certainly not the cartridges ( that's why we need those tonearm facilities. ), but the " success " or not comes through which and where we all accept trade-offs: where a trade-off made/makes less harm.
Regards and enjoy the music.
Raul. |
Raul,
well said! BUT in order to understand this position you take, it needs some intimate knowledge of the subject matter --- and unfortunately this takes time, and more importantly interest AND motivation to acquire it.
A lot of folks don't want to know the details of their car's differential gear, but simply use it.
So, that said, it might make a case for Linn and SME's non-variable approach.
I'm also not really sure if a very 'funky' adjust-all approach is the last answer to all this.
As with all things, learn as you go --- THEN make a more informed decision, on what is best for your needs AND preferences, or?
Thanks for your ever present words of wisdom, it always makes for good reading.
Axel |
Dear Axel, as for your quote:
"""""A lot of folks don't want to know the details of their car's differential gear, but simply use it.
So, that said, it might make a case for Linn and SME's non-variable approach.
I'm also not really sure if a very 'funky' adjust-all approach is the last answer to all this."""""
The reason why today we can just enter the car and drive without knowing the details and without having to adjust some things before starting the engine is, that in the past 100+ years a lot of well-educated engineers have put endless work into the complex topic "automotive car" and have solved all problems (and there were an endless number of problems in the early decades and still today cars are improving).
We are far from that state of development with analog front-end.
Far less time, far less high-trained manpower, far less money.
Till we can use analog front-end with the same ease as our cars, I will have a long white beard...... and I am not that old yet. |
:-) Dertonarm,
Mine is not long, but white for sure, and SME's founder is dead by now.
It must have been at least their intention to move on with all this fiddly-dilly alignment stuff. I feel obliged to give them credit for it, even one can't agree with it all at times.
Incidentally, I just learned by John Carr himself, that Lyra got it right on target with the stylus-tip to mounting hole-distance 3/8" = 9.52 mm tolerance +/- 0.3 mm.
So, yet another step in the right direction.
Get a Lyra, get an SME, and stop worrying about your 'differential'-> alignment(s).
Jolly good show, I say!
Best,
Axel |
Maybe one of the " weird " tonearms ( on stylus alignment ) was the SAEC 506/30: the builder specs are 295mm on effective length with 9mm on overhang ( many trouble with some cartridges because to achieve 9mm there is almost no space in the SAEC headshell for the cartridge connector pind and the headshell wires. ), where the pivot to spindle distance is 286mm.
Well if we run Baerwald with that EL ( 295mm ) then we have an overhang of 13.8mm that give us a pivot to spindle distance of 281.2mm.
I wonder why SAEC made this compensation ( 5mm ) with the whole numbers where they choose the overhang of 9mm that was a pain for say the least?
Regards and enjoy the music.
Raul. |
Dear Raul, I will set up - for a friend of mine - a SAEC-506/30 in two weeks - mid May. I will have some news and geometrical details after I have done so. If anyone interested, I will gladly supply all findings. |
Other SAEC the WE8000/ST has 13mm with 302mm in EL as manufacturer specs but through Baerwald/Lofgren calculations we have: 13.5mm/13.9mm on overhang.
So I think that the SAEC owners could try those overhang calculations on it and in the the model 506/30: 13.8mm in overhang and 281.2mm on pivot to spindle distance.
Regards and enjoy the music.
Raul. |
Dertonarm: Thank you.
regards and enjoy the music.
Raul. |
Hello to everyone,
A few facts that proove some of the above wrong or, at least, serve as food for thought.
Actual Lyra cartridge measurements, mounting hole to stylus:
Dorian: 10mm
Helikon: 8mm
Titan: 9,5mm
Olympos SL: 9,3mm
Other examples showing that there was never a "norm":
Clearaudio Insider Ref. Wood: 8mm
EMT JSD6: 10mm
Koetsu Black Gold Line. 10,8mm
Decca Maroon: 11mm
Denon DL102: 12mm
I have encountered anything from 6 to 13mm(9,3mm the average so far)...
It is not true that the sonic difference between an arm of 9" vs 12" eff. length is solely attributable to the reduced tracing error related distorsions if the arm cartridge resonance with a specific cartridge is identical.
Simple proof: They will sound different even at the null points.
Some reasons for perceived(and measurable) differences in well known arms:
Higher load(reduced bearing "chatter") on the (knife edge)arm bearings(SME 3009 vs. 3012) due to larger counterweight mass.
Energy storage and release differences due to heavier counterweight on longer arm.
Torsional and bending stiffness reduced on longer arm since most manufacturers maintain the armtube diameter and wall thickness on their 12" arms, i.e. Moerch(likely for aesthetics and/or cost saving).
Consequently, the resonance spectrum(as in "ringing", not fundamental arm cart res.) of the longer arm differs from that of the shorter arm.
It makes no qualitative difference whether one approaches the choice of tonarm geometry from the eff. length or the pivot to spindle distance. The clear advantage of changing the pivot to spindle distance to adjust overhang is simply that one doesn't need to readjust VTF. There is also no risk to accidentally "turn" the cartridge while moving it forward or backward in the slots or while tightening the cartridge screws.
A mechanism allowing for the change of arm position(p-s distance) à la SME, LaLuce or my own is simply harder to produce than a slotted headshell. BUT(!!!), if one chooses this geometry alteration scheme, one also HAS to allow for changing offset angle, albeit within a very small range. Typically there is enough "slack" between cartridge screws and headshell holes for that and a separate, "turning" cartridge mounting plate offers even more room for adjustment.
The best protractor is the one that, for an individual, repeatedly results in an alignment close to perfect. So it is not a question of which protractor, but which person uses it(as long as the protractors are otherwise geometrically correct).
There is no "universally perfect" tonearm alignment. For each record, one perfect alignment exists, defined by the actual used/grooved area. To find the best compromise for YOU, you just need to examine/measure all of your records to come up with an average figure which will differ from IEC or DIN standard.
Many "old school" arms were used to play back singles and transcription discs at broadcast stations. The often questioned choice of an inner Null point near or at the LP "end" groove(r=53mm) makes sense when you want to playback singles(end groove r=48mm) without excessive tracing error related distorsions. Not recommendable if you sold all your singles at a yard sale years ago...
Bob Grahams pivot to spindle jig and hinged overhang gauge work well if you achieved what he wants you to achieve. But if your pivot to spindle distance is off due to poor machining skills(I've seen this more than once)you are repeating the resulting mistake with any new cartridge that you are mounting. Any maybe you have a different idea about the best alignment...
Any cartridge can only perform optimally if the alignment is as close to perfect as possible. In reality cartridge cantilevers/stylii are rarely at 90° angle to a line connecting the mounting holes. Any arm that doesn't allow for at least 2° of offset angle variation/alteration may limit the cart's performance. Don't get me wrong, I don't advocate sloppy cartridge manufacturing, but reality equals imperfection. And as cart suspensions age or with too much skating compensation, the problem gets worse.
Same for Azimuth...
The original question was never addressed. Do linear arm sound better across...
Short answer: yes, but only if you compared two otherwise identical arms. No commercial examples exists, so that debate is pointless.
Let me repeat that it is not correct to say that a tonearm has to have a fixed pivot to spindle distance to be regarded as having a "correct" geometry. If the arm features the required provision to alter the offset angle, it's just as "correct". It will have a "nominal" eff. length, the actual eff. length being a function of the cartridge in use. Arc protractors and Graham style alignment gauges(as good as they are)are therefore out...
One could derive a question from this thread's headline which is directly related to the original post:
What is the threshold for the audibility of tracing error related distorsions? - and: How "tolerant" are the various stylus profiles as tracing error increases?
Time for dinner...
Cheerio,
Frank |
Hells Bells,
here comes a man that actually makes the stuff (Frank) and tells me what I was arguing for 101 questions and answers with DerTonarm i.e. the spindle-to-pivot distance is not of this ultimate importance to be even close to 0.1 mm according to some geometry decided spec.
You just compensate with the off-set (turn the cart some more left or right) someone must have heard me cry for help.
So now you have it from an arm designer and manufacturer. Very nice Frank, thank you for sharing, time for bed.
Greetings,
Axel |
Hi Axel and the rest of the "gang",
Here are the figures relevant for an SME V:
Let's say cart A has a mounting hole to stylus distance of 9,5mm, cart B is unusually "short" and features 6,5mm mh-s distance and finally, we have cart C, the Jaguar E-type of cartridges with 12,5mm mh-s distance
Required for Baerwald alignment(other alignments possible too):
A: 233,15mm eff., offset angle: 23,63°, pivot to spindle distance: 215,35mm, overhang: 17,79mm
B: 230,15mm eff., offset angle: 23,96°, pivot to spindle distance: 212,11mm, overhang: 18,04mm
C: 236,15mm eff., offset angle: 23,31°, pivot to spindle distance: 218,61mm, overhang: 17,55mm
So all that is required is enough slack to rotate the cartridge by little more than 0,3° either way and slide the base forward or backward about 3,5mm, both of which are easily achieved.
Even the "tightest" headshell holes leave enough room and before anyone takes out a reamer to mess with his SME, just reduce(every household needs a small lathe ;-) the diameter of ONE cartridge mounting screw towards the head, leave the bottom part where the thread engages with the cart alone and you have enough leeway for even badly skewed cantilevers(better just send such carts back to the manufacturer).
And many cartridges have cantilevers that are off by more than the above mentioned 0,3°.
Have fun guys...
Frank |
Frank,
That suggestion to file down ONE cartridge mounting screw at the top is pure elegance. Simple, effective, and no damage to the arm. Why didn't I think of that? There was enough play in my mounting holes to allow me to rotate my cartridge in the SME V slightly to achieve the proper offset angle according to my protractor.
I'm curious. You mention in your earlier post that an arc-type protractor will not work if effective length has changed. This should not hold true for a protractor that was designed with a specific cartridge and arm in mind, or am I missing something?
You seem to describe perfectly what I have experienced with my SME arm and cartridge. Thank you. |
Dear Frank: Welcome a-board.
+++++ " What is the threshold for the audibility of tracing error related distorsions? "+++++
IMHO the " start " subject here is to define/identified first which are and how we hear those related tracing error distortions over the frequency range, certainly we can but is not an easy task especially if we want to define the threshold/limit.
There are some " difficulties/obstacles " other than system quality performance: the wide differences on the velocity recording through the LP, certainly the tracing error related distortions are different at outer grooves than at medium or inner grooves and we have to identified over the whole record, as you point out we have additional " problems " because of stylus shape, different tonearm/cartridge combinations could be more or less " tolerant " about, our ears and know-how level is important too, there is other subject: there are distortions that are incorrect but we like it ( many of us do not like low distortion sound, many people likes higher distortions/colorations. That's why we have to identified the incorrect distortions due to bad geometry tonearm/cartridge set-up. ), etc, etc
Of course that we can do it in a scientific way making measures and then listening till we find for specific grooves the limit to start/begin to hear " distortions " related to tracing error due to bad geometry set-up.
From my mistakes/errors ( like the one I posted elsewhere with the FR702. ) experiences and due that we live in an analog imperfect world it seems to me that that threshold is wider than what we imagine and cmplex to be absolute precise by ear only.
In the mid-time we have to take care on every single step on the tonearm/cartridge rigth and " precise " set-up.
The 90% of what the people ask in this forum, one way or the other, are related with distortions ( everywhere and any kind ) due to an incorrect audio items set-up.
I repeat again, we have to take care on a precise audio link set-up on the audio chain.
Anyway, I know that there are other tonearm designers that are reading this and other related threads, I hope they want and can joint us to share their thoughts and experiences about.
Regards and enjoy the music.
Raul. |
Frank,
thank you for all that common sense approach.
I happen to be a trained engineer myself (old school German Mechanics) and I can only agree, that IF you need to get 'anal' about some of these setting, be aware what is 'value added' to improve things, not just for the sake of doing 'something' that might be of little effect in practical terms.
Having said that, in my present experience and so far with two of Ortofon's top MC's --- they have a problem to get their motors in the middle of that sintered body shell. Funny thing, it is hardly, if at all, an issue with their cheaper lines i.e. the Kontra-Punkts. It is to my dismay an issue, that for some unknown reason, with their more expensive Jubilee and PW lines.
What seems a constant here, is the motor being closer toward the left cheek of the body (looking from the front). This creates some, at least for me, more intricate issue since the cantilever is straight as such!
Of course, not being anal about it, just turn the cart a little to the left, if 6:00 o'clock was straight, say to 6:03, and call it a day.
Being now being anal about it, the cart would have to be actually offset at 6:00 to the right, i.e. NOT turned, but shifted toward the right to compensate for the left offset of the motor. The offset is about 0.3 mm and quite noticeable by only looking at it, straight from the front.
In your experience will it be all the same, or actually make a difference in practical terms (in geometry there will be a difference, I say)
Greetings,
Axel |
Dear Berlinta, the choice of an inner (2nd) zero close to the label makes sense too, if you own a large collection of early classical stereo LPs made by Mercury and/or Decca (to name the 2 major labels who hadsome of the most daring cutting engineers...) in late 1950ies and first half of the 60ies.
Ask hundreds of collectors of valueable vintage LPs.
Here we often have run-out grooves sometimes starting within less than 8 mm before the paper label. Especially with some of the most dynamic recordings. And then the large final tuttis are very close to the grooves end.
Its not all singles.......
There never was a "norm" from IEC and the AES for the stylus - mounting holes ?
Well - there was and is one.
The fact that so many manufacturers do not obey to it, doesn't mean there is none.......
Anyway - these are windmills....... I won't make the same mistake as Galileo did. I leave the discussion in this thread for good - this step will surely get some applause, as it leaves the field to others to shine........ and increase their sales. |
Dear all, after we have now learned that finally all parameters of the tonearm geometry are variable, nothing can stop us now entering analog heaven.
If any of you will still suffer inner groove distortion....... well, don't worry that happens. Move your tonearm, rotate the cartridge. If it distorts now at the run-in grooves? Hey - be flexible. Times may be hard, but modern. |
Hello Peterayaer,
An arc protractor works perfectly for one specific effective length only. This requires the cartridge to be moved (i.e. in the headshell slots) to match that length as precisely as possible. Any arc protractor designed for a particular arm cartridge combination(-your question above) should have taken actual measurements as a base for fabrication. Unfortunately, as described by Jonathan Carr, the sample to sample variation in cartridges(screw hole to stylus distance) often exceeds what could be seen as an acceptable tolerance (= below human eyesight limitations), resulting in grounds for error even if the same arm and cart model are used.
But the Null points on an arc protractor are valid regardless of the arc itself. It is only the circle segment line which needs to be re-drawn.
Cheers,
Frank |
Hello Axel,
Believe me, I'm anal about cartridge alignment...
If the generator isn't mounted dead center inside the cartridge housing and you can't shift it by 0,3mm, then you'll have to rotate it and slide it forward or backward, depending on the generator being closer to the right side or the left side of the cartridge body.
BUT, the magnitude you described will cause an error so small as to make it near impossible to correct for it reliably and repeatably.
As an example, let's assume your cartridge generator is so far offset(sideways) that it causes the actual offset to be reduced by 0,5°(a larger figure than what can possibly result form generator displacement). Your eff. length is shorter than "normal"(let's say, by 0,3mm), if you have that cart mounted in an arm with fixed holes.
Here's what you get(SME V specs as a base):
Unaltered:
eff.L.: 233,15mm, Null points 66 and 121, average distorsion 0,42%
Now it gets interesting: distorsion at 61mm(inner groove area): 0,54%
Reduce the offset due to shift by 0,5°:
eff. L.: 233,15mm, Null points 71,4 and 111,8mm, average distorsion 0,389%
Distorsion at 61mm: 0,95%%
Additional compensation of eff. length due to shift, -0,3mm:
eff. L.: 232,85mm, Null points 71,8 and 111,1mm, average distorsion 0,393%
Distorsion at 61mm: 1%
Draw you own conclusions...
My take on this: Most people can make out a 0,3mm difference when aligning a cartridge. VERY few can tell the offset angle(sometimes referred to as "zenith") being off by any less than 1-2° !
It's the inner groove area where this really comes into play.
Cheers,
Frank |
Dear Dertonarm: The understanding and know-how in almost any analog audio subject is a matter of in which level/point of any audio subject learning curve we each one are.
In an open forum and due to different experiences at different level ( good or wrong ) is too dificult that everyone of us agree totally, specially in an almost " new " stylus set-up.
Through these related threads on the subject I'm still learning things that could help in my tonearm design.
In my last post I speak about my mistakes/errors on cartridge/tonearm set-up over the time, well the last one was during one of the tests on my tonearm design:
" changing and testing an arm wand ( different build material ) by error ( I'm testing on prototype unit ) the arm wand was out of position on " length " distance and I put the same headshell/cartridge ( that already was checked on overhang ) with out checking again the stylus position in the pro-tractor because I can't " see " my arm wand position error.
Let me tell you that the error was not 1mm but almost 4mm( maybe more, I did not measure. ): Well that arm wand build material was so good that even that the set-up was totally wrong the sound was even better than with the other different arm wand and this fact impede me ( at that time/moment ) to know about the mistake
When I take in count of the error I fix it and the performance improve. "
One tool that help to take in count that error was to hearing my record tracks that i use like references.
But this error help me to understand ( I'm not saying is correct ) about that threshold of hearing with that kind of errors and of the importance not only of a tonearm build material but about its whole quality.
There are many subjects around that make so complex the whole tonearm/cartridge set-up. What is true is that we must to be really precise/scientific on the tonearm/cartridge set-up to obtain in a " better/best " way what is in the recording.
Anyone can do what they think/want but that does not means that always is rigth, is different with different distortions that are usualy higher than follow an orthodox method.
Of course that everyone is free to take the Lofgren/Baerwald and others work and put on the trash can. We live in a " democratic "/free world.
Regards and enjoy the music.
Raul. |
Hello Dertonarm,
Since my record collection numbers about 10000 with more than 60% being classical(and about 1/2 of those dating to 1965 and earlier), I know exactly what you are talking about.
I chose singles as an obvious example to make a point about tonearms used on broadcast turntables.
Yes, the IEC norm exists(the AES merely recommended it), but, as you said, was never universally adapted. We just have to deal with what's in existence. TP4 as a norm wasn't that big a success and a norm for 1/2" mount carts would limit cartridge designers in the future. If everyone would agree on a reasonable range for several cartridge dimensions, not just the mounting hole to stylus distance, but i.e. the height of the cart too, the consumers might be benefitting from it.
You are comparing yourself with Galileo? I hope you're not implying we're all out to crucify you , yet still live in the dark ages.
I for one like a civilized discourse, but not ego battles. So please come back anytime..
The remark about "increasing sales" is inappropriate and unfounded. If you have something to say, say it straight.
Ein schönes 1.Mai-Wochenende wünscht
Frank |
Hi again,
Dertonarm:
"Dear all, after we have now learned that finally all parameters of the tonearm geometry are variable, nothing can stop us now entering analog heaven."
Yup, if your tonearm offers the key parameters to be varied, you can indeed implement standard alignments(B,L,S) or even move the Nullpoints according to your own preferences(better do the math first...)
"If any of you will still suffer inner groove distortion....... well, don't worry that happens. Move your tonearm, rotate the cartridge. If it distorts now at the run-in grooves? Hey - be flexible. Times may be hard, but modern."
Cynicism doesn't help. Applying math does.
Best,
Frank |
Dear Berlinta, it is very difficult to say something "straight", if your post is not approved by the moderator and therefor never actually posted (which happened with several of my posts in the dispute about the turntable drives when I was "against the gang" - thats why I moved out of that discussion).
Galileo was an analogy of course, as were the windmills - but I think my point is clear.
For many small audio business today the online forums are the best way to marketing their product(s).
To do so, they must maintain their status of authority in the segment of the audio market their product is located.
This is legitimate - of course.
When this status is endangered in any way, it becomes an ego battle very soon - quod erat demonstrantum in the discourse about the bearing friction which became a dispute about turntable motor drives in general. |
Dear Raul, you are right.
Maybe its just one dogmatic ego which can't stand his mirror image......
I just do not see the term democratic transferable to the world of physics, mechanics and geometry. |
Dear Berlinta, as I announced before: - I leave this thread now.
Our dispute doesn't bring this thread forward in any constructive way. |
if the tonearm is aligned to closer to zero tracking error at the inner grove you should not hear any distortion or mistaking if you stylus has a good polish, cartridge suspension is good and tonearm is good mechanical match for the cartridge. Mastering engineers usually compress the dynamic range of inner tracks or put low dynamics tracks there. The limitation is obvious: they have to fit same time of music into less linear grove distance. I noticed that modern productions cartridges are not coping very well with problems of inner grove. I'm attributing this problem to much lesser styli quality today even at the highest price levels that it was in 70x-80x even at pedestrian level prices. There are obviously always exceptions today, such as Denon. Just to give you some examples: my Technics EPC-200CIIL, Micro Acoustics 630MP, Audio Technica AT20SS and half a dozen other MM and MC cartridges don't show any distortion. |
I know, it is not transferable, that was not my means on the subject but that only a few people make what it's suppose the best to do: physics, mechanics and geometry.
Regards and enjoy the music.
Raul. |
Dear Siniy123, I absolutely agree with you.
With classical music however the mastering engineer has no choice, but to put the tracks where they belong. As most of the big climax in classical (especially of course symphonic music...) music are at the very end of the movements we usually see the end of a romantic symphony towards the inner grooves.
As we can do little to get the industry alter the polish/stylus quality, we should optimize the position of the stylus at the most critical part of the groove.
Thats why I vote for an alignment which puts the 2nd zero closer towards the inner grooves to bring the stylus in the best possible position when the going really gets rough.... |
Dertonarm, you and syntax were saying about the Dennessen soundtraktor for alignment. Was wondering if it is the same one as the one listed on audiogon with only 1 grid???? Does it have 1 or 2 grids?
TIA |
Genesis168, the Denessen Soundtraktor has only one grid/one point for alignment. |
Thanks! I finally found one. Just wanted to make sure before I take the plunge.
TIA |
