Does anybody know the right parameters for the VPI Memorial 12 (original) tonearm? precise information regarding any and/or all parameters will be appreciated. I have never been able to achieve the arm's offset with the cartridge which makes me think I have room for improvement. Please note that this arm was provided with no information, VPI does not publish it. Also, newer versions have "enjoyed" the attention of a few aficionados who have rendered the goods, but... I don't think the wands geometry is the same between the old one and the newer ones. |
The P2S addition makes the UNI-protractor really universal. It took a while Dertonearm! but the solution you finally came out with is just a sensation - I usally don`t use such extrem words.
I was always trying to build something by myself - you will remember. Oh my god! Really good things may take a while! I tried it on my TTs and arms and it is such an easy job using all different tonearm inlays while adjusting tonearm length and exact needle point on the spot by 4 digit precision.
Well Done!
As I am also an "image guy" I put one onto my page.
best & fun only |
Dear Sonofjim, right now the UNI-Protractor is readily available and ships within 8 working days following order.
Due to very good sales in the 1st and 2nd full production run we decided to produce some "overstock" and can supply limited quantities now much faster than before.
If you are interested, I will gladly send you the full pictured 24-page manual as PDF-file to get a comprehensive impression about the functions and options the UNI-Protractor does offer.
Best regards,
Daniel |
Where is the UNI tractor available? The listing here has expired. Is this because it's back ordered or between production runs? The Mint is cartridge specific when used on SME tonearms. I assume the UNI would be a good alternative and not cartridge specific. |
Dear Ecir38, yes - the UNI-P2S is a stand-alone-device.
It features 0.05 mm accuracy and can measure mounting distance up to 15" or 38 cm. It has some unique features of it's own.
The UNI-P2S nevertheless can be used in close conjunction with the UNI-Protractor and offers then direct measurement of mounting distance with 0.05 mm accuracy during alignment of cartridge.
In other words - you can read down the exact mounting distance every moment during actually aligning your cartridge.
It was quite some work to design the P2S so that it now meets the universal approach I was longing for.
I will introduce the UNI-P2S next week and it will ready for order and immediate shipment by end of July 2011.
Cheers,
D. |
Dertonarm, will you be offering a stand alone P2S?
Brad |
Dear T_bone, dear Wrm57, let me add some technical parameters to the discussion.
The UNI-IEC features zero points at 116.39 and 67.44 mm radius (very close to what T_bone once named "Dert67" ... ;-) ...).
After radius approx. 117, this alignment has approx. 20 % less tracking distortion due to tangential error then Baerwald IEC and is very similar to Baerwald curve after radius 66 mm.
A very suitable alignment if most of the records played are made past 1982 and feature rather long wax/lead out groove.
UNI-DIN features zero points at 109.52 and 63.49 and is ideal suited for stereo records made in the early days with short lead out grooves/grooved area running close to the label.
Both alignments to pay attention to certain aspects of stereo stylus with decreasing radius and concentrate the focus of minimized tracking distortion on the last 2/3 of the groove.
The long awaited UNI-P2S will finally (sic ...) be introduced next week. It proofed much more tricky to integrate it's function with the UNI-Protractor, but finally I succeeded and will bring something rather unique in both - function and precision.
Cheers,
D. |
Wrm57,
Thanks. Not sure what the UNI-IEC is... I am curious. I will have to dig further. |
The Baerwald alignment using the UNI-Pro sounded better on the Graham than the Wally and better on the Universal than the MintLP. It also sounded better than the UNI-IEC alignment. At some point, I'll go back and realign again using all and recheck, but I was pretty careful the first time through the process, so for now I'll just enjoy the music. |
My templates are labeled UNI-IEC and IEC Baerwald. The former is Daniel's recalculation of the Baerwald geomtery, as I understand it. |
Wrm 57, There is this German saying: 'If theory and practice coincide then they are probable both false'. However in theory there should be no difference between the
Mint Lp and the UNI-pro in your case. So, I assume, you like Dertonarm more then Yip ?
Regards, |
Wrm57,
Which UNI-IEC template did you try? And was the Baerwald template IEC or DIN? (or other?) |
I've been spending some time with my relatively new UNI-Pro this weekend, aligning an A90 on a Graham Phantom II and a Benz Ebony LO on a Clearaudio Universal arm. I also a have a Wally and MintLP for these arms, respectively. After some initial getting-used-to, the UNI-Pro is simpler and quicker to use and I prefer the results. Checking UNI-Pro Baerwald against the arc protractors, the alignments are not identical despite the fact that both arms (and their protractors) are based on Baerwald geometry. This discrepancy gave me some pause at first, since I've always relied on the arcs. However, I find the sound is notably better using the UNI-Pro. It's deeper, cleaner, more detailed, more relaxed. I'd conclude that means the alignments using the UNI-Pro are more correct. I should add that I prefer the Baerwald template to the UNI-IEC template. It just sounds better to me. Nice job, Daniel! |
Dear Bydlo, the cart in the EMT shell is a modern EMT cartridge, a JSD 6 made by EMT Studiotechnik GmbH. As I like the Tondosen too, especially the new designs, this one is superior - maybe with the exception of the Lzi but this is carrying a SME shell.
You may align also Tondosen with the EMT gauge or the UNIprotactor.
best & fun only - Thuchan |
Ah, now I've got it Thuchan after seeing the pic (but the email is sent anyway :-)). I've missed that you use a different cart in the EMT shell. I thought you were aligning Tondose. Sorry for bothering
you&thanks for kind answers :-)
Best,
--j |
Dear Bydlo,
you may align EMT arms with the EMT alignment gauge. If you send me an e-mail I will answer and attach it. The better and more precise alignment you will reach with the UNI-pro coming with the 997 or 929 inlay. This is what I did. You can see it on one of the images on my page.
best & fun only - Thuchan |
Just received it, very easy to use and fuss free. Another step forward for me. I would like an arc for confirmation on overhang though. |
Dear Tuchan,
Please excuse my ignorance, but how does one align EMT arms?
I have a 929 with TSD15 mounted on 930 and have been wondering if there is anyway to check/correct the geometry?
Thank you!
--j |
I just aligned my EMT 997 tonearm (NOS old design) with the UNI-Pro's 997 template to reach the full EMT geometry. I compared with common two Null-Point protractors and also with the one of EMT.
I did not reach such an exact and precise alignment than with the UNI-Pro. When I switched between Baerwald IEC and (for Monos) Baerwald DIN and back again to EMT you only have to check if you have put the Micrometer screw again on the right position.
best & fun only - Thuchan |
Hi Jazzgene, the "black" reticule proofed much more difficult to produce in equal quality than estimated. This is not laser etched, but has to be printed. We finally got a perfect inspection sample this week and will get the full production run next week.
Best,
D. |
Dear Dertonarm,
wonderful - see you next week.
best & fun only - Thuchan |
Dertonarm,
Any news about the reticule with black markings for silver arms? Looking forward to it. |
Dear Thuchan, the full 2nd production run of the UNI-Protractor was just collected by the shipping service. I wanted to have this on it's way first before actually introducing the new UNI-P2S.
The UNI-P2S will finally be introduced and in stock by mid next week. Around the same time when you'll get your special balanced multi-line-to-power amp switch unit ...;-) .....
Stay tuned and enjoy the Munich High-End show tomorrow.
Cheers,
D. |
Dear Dertonarm,
any signs of the UNI-P2S having left the labratory or even production stage. The world is waiting...
best & fun only - Thuchan |
Dear Chris, my last post just crossed with your answer - indeed, the bearing of the ET 2.5 can take much higher pressure. I found my tonearm files with the remarks about the ET 2.5 and my last settings were around 1.0 to 1.1 bar - which is, as you mentioned too, about 16/17 psi. Beyond that the re-bouncing airstream and material instability did downgrade the ET 2.5's performance.
Thanks, Chris - the sales on the UNI-Pro exceeded my expectations indeed.
The 2nd production run sold out again.
Cheers,
D. |
Dear Chris, I found my old files ... last setting with the ET 2.5 was 1.2 bar. Notes further mentioned "threshold - can't take more pressure due to material and problems with re-bouncing air stream".
Cheers,
D. |
Dear D -
That Apolyt is quite the platter and those arm pods. :)
My extensive testing of the 2.5 showed me that 6-8 working psi is a very safe albeit too LOW psi for the 2.5 to show its stuff. So am not surprised at your earlier remarks.
I found the ET 2.5 starts coming into its own around 16 psi to about 20 psi. My findings were later confirmed by Arthur Salvatore who told me his members recommend 19 psi. "Above 19 psi and the arm starts to lose information".
At 19 psi the ET 2.5 has phenomenal PRAT, Bass Attack, HF, sounds the most natural. It competes with arms well above its $2900 US purchase price. I very much recommend to those with the ET 2.0 to have them upgraded to the 2.5 bearing along with a Timeter Aridyne medical pump available on Ebay. These two mods make the basic ET 2.0 arm are a giant killer.
Good luck and much success with your Uni D.
Cheers Chris |
Dear Chris,
my ET 2 was mounted first on the big Le Tallec tt (modified) and later on the Apolyt (450 lbs chassis, 100 lbs composite platter on radial/axial air bearing, 2 Hz air suspension frequency of whole turntable).
The ET 2.5 was mounted on the Apolyt only.
I worked mainly - as far as I recall - with 0.4 to 0.6 bar.
In american psi this means 6 to 8 psi approximately.
This was read down at the Apolyt's control board.
Cheers,
D. |
Thx for the quick reply D and clarification on the lack of issues other than pump sources with the ET. I have had no cartridge issues in 5 years and it is my main arm.
Is the UNI tangential tool similar to the ET supplied one. I am looking for something that would let me square the line better from the spindle to the bottom of the straight sp10 casing. I am using a homemade extender right that does the job but am curious.
One final question.
You said
"The ET 2.5 improves considerably with increased air pressure up to a certain limit". It does deliver very good bass with a lot of "body" - but not quite the quality I seek."
Are you able to recall what platform/table you mounted the 2.5 on and what PSI you registered at the air bearing, not the pump source.
Thank You Chris |
Hi Chris,
last topic first .... yes, there is also an UNI-template for tangential tonearms.
1) "We" was referring to the audiophile community - including me.
Kind of universal - in the sense of "we, the people" - i.e. not a club nor a circle of friends, but all audiophiles in the past 4 decades.
2) With mechanical issues I meant that tangential tonearms do ( with various intensity however ) put the suspension of a cartridge's cantilever to considerable stress. Even in a servo controlled tangential tonearm there first has to be a declination from the tangential right angle to move the tonearm.
It is not an apparent immediate issue, rather a long term problem.
I worked with tangential tonearms for 11 years.
There were and are cartridges which are mechanically better suited to withstand the mechanical stress ( especially Supex SDX-1000, original small body ZYX) and a great many which are not.
I didn't really did run into "problems" with neither the ET2, ET 2.5, Air Tangent 2B, Air Tangent Reference nor Goldmund T3F.
I all had them on my turntable(s) and they all did perform quite well and some showed potential for great sound.
I used them with high tech air supply ( Jun Air "Troll") and adjustable pressure and air volume.
The ET 2.5 still today is a best buy.
If mounted with the right cartridge ( low body weight, solid suspension ) and if you do not ask for the last punch, dynamic, air, color and detail in the lower 2 registers of the audio frequency band.
The ET 2.5 improves considerably with increased air pressure up to a certain limit. It does deliver very good bass with a lot of "body" - but not quite the quality I seek.
It is a very good tangential tonearm and if I were looking today for a tonearm in the $1k to $2.5k range, it would still be high on my list.
Cheers,
D. |
Dertonarm Again, since you were the one who brought it up, you said: If you think you can do better - go ahead design it. I already have - as soon as I saw the pics I knew you had missed the basic principle of the Dennesen, and, by extension, the underlying concept, which goes back to Percy Wilson in 1924. Anyone who understands the principle could, with a bit of thought, see how you could have made your protractor more universal, more precise, and easier to use, without compromising the existing features (and you can admit having used it for 25 years, yet haven´t seen this!) You said: So far your comments have shown little more than poor judgement, a fairly high aggression and very little understanding of the subject. Yes, bad judgement in expecting anything other than obfuscation. Aggression? Scarcely. Understanding? I can only promise to try and be more understanding of your explanations. You said: I welcome your attempt to put your name on the wall again and to prepare the road for yourself for a soon-to-be return to the audio market.
No problem with me - as far as I am concerned you are certainly welcome. Thanks, spoken like the true salesman you are. But, unlike yourself, I have no plans to market my add-on to the Uni-Protractor, to compensate for its non-universality. (Nor my new 12" FR66-killer zero antiskate adjustable effective length, dynamically balanced, irregular-pseudo-elliptical headshell arm, (or even my headshell mounted miniaturised preamp which uses the power gained from negating various mysterious breakdown torques to enable a single run of fine cable from the cartridge to the power amp...)) You said: I might react to a post by you from time to time only, but so far very few actually did ask for an answer or a comment. Most were simply lacking content and seriousness. Luckily my last post had two straightforward questions for you to answer, so you might start there. As you must have missed one of them, and misunderstood the other, I´ll repeat: in what way do the Reed, Talea and Schroeder differ from other arms? The Talea and Schroeder appear to have a facility to alter the effective length,(as does any other arm with a slotted or movable headshell) and they have a facility to alter the headshell angle. What is the difference between this and altering the angle in a normal headshell?
The Reed has a normal slotted headshell except for the model with its little azimuth adjusting device.
What´s the difference? I would honestly like to know.
And I am intrigued to know what are these mysterious additional breakdown torques which the above arms don´t have. Cheers again |
Dertonarm Allow me to return the rattle that you have thrown from the pram: You said: you don't really want me to tell you what additional breakdown torque is and why it does of course influence the skating force. If I didn´t wish to know I wouldn´t have asked. I´m always willing to learn something new and if you have something new to say, I´m willing to hear it. It is just that you seem unwilling or afraid to actually say anything at all - commercial reasons? You said If you think skating force is just a phenomenon of friction and downforce - fine, certainly no problem with me. I didn´t say that. A neat attempt at misrepresentation. You said If you muse about the model and draw yourself a good and precise force vector model of a pivot tonearm, you'll figure out. I have done. A long time ago. And since then I have re-considered my original thoughts and am willing to continue doing so in the light of new facts. You said: I did suggest starting a "antiskating thread" - I didn't say I want to start it nor did I say I want to participate in it.I have no questions regarding skating force in tonearms. But a lot of talk and precious few answers, it seems. You said: Regarding the UNI-Protractor and it's "universal" use.
Apparently you haven't worked with it so far and haven't understand it's principle either. Otherwise none of the comments in your last two posts would have been made. I think you´ll find it was I (not you)who briefly explained earlier the way your protractor works. I don´t know if you´ve done this elsewhere, but you don´t do it in your audiogon advertisement. Neither do you credit, or even mention, Dennesen at all in your ad. You say I don´t understand the principle you used. I understand it only too well. cheers . |
Dear Dertonarm.
Spring rain kept me from chores so I did some reading on Agon looking to learn. I read through this Uni thread from the start and came across a post you made on March 11 that is puzzling to me.
Specifically you said.
the linear tracking tonearms - in any incarnation we have seen so far from Rabco, Denessen, Goldmund, Versa Dynamics, Air Tangent, Eminent, Forsell et al -displayed mechanical issues, periphery problems and stability problems which did always crippled their undisputed tangential advantage.
Most audiophiles who ever ventured into tangential tonearms later moved to tonearms with 11" or more effective length to approach kind of "best of both worlds".
I have had all the above named tangential tonearms in most all their incarnations in my system in the past 30+ years.
Wow quite a statement. Two questions.
1) Can you tell me who we is when u say "in any incarnation we have seen" ? Is that an audiophile club?
2)
I have owned the ET 2.0 and now 2.5 arms for the past 5 years so your statement caused me some despair. Is there an unknown problem I am not aware about? Would you please be so kind to enlighten me for the Eminent Technology arm specifically that you owned - about the stability, mechanical, etc
problems you had.
I found alignment tools provided with these linear arms get you to about 75% of their potential. The rest is trial error tweaking by ear. Personal discussions with Mr. Thigpen have confirmed this. You need to experiment and try different settings. See what u like / dislike. Once past the initial tool settings it is all FEEL, ADJUST, LISTEN. Definitely not plug and play but once set up you can forget about it without issues I have found.
All problems I came across in my earlier days with the ET arm, and in talking with other folks about linear tracking arms in general - other than pump/air problems easily fixed - have always been related to actual user errors and the lack of "total knowledge" about the arms and the way they work thus leading to improper setup. After 5 years I am still learning about my ET arms and how they work.
I look forward to hearing back from you when it is convenient on "your ET specific problems" as you say u owned the ET. You did not say whether it was the 2 or 2.5 version.
Lastly does the Uni package contain any tools that would be useful for lining up linear tracking arms ?
Thank you. Chris |
Dear Peterayer: That is only an " exercise " that you could do it when appropriate to you.
Regrads and enjoy the music,
Raul. |
Thanks Raul. I think I understand now. Unfortunately, it takes a fair amount of effort and time to move my TT to properly realign the cartridge after doing such an experiment. I'm presently satisfied with the sound, so I'd rather not mess with it now. I may try it at some later time. I'm sure I could learn something as you suggest. |
Dear Peterayer: Please forgeret about distortions for a moment and suppose that you made ( for whatever reason, never mind here. ) a " mistake " and mounted a cartridge 1mm-2mm forward/rearward of what an accurate protarctor asked.
As you said it you will heard/hear a cartridge that was not aligned properly and this is the subject of this simple " experiment ".
What could you listen or find out? well that's what this test will tell you.
Other than that non-properly alignment nothing that you share with us can have a " negative " argument by any of us. The important subject is what you heard: what you like it, what you don't like it, if you could live with these trade-offs and what do you thing overall against the properly alignment.
IMHO this kind of tests are interesting ones and I have to say that by " accident " ( my errors. ) I heard many times cartridges that were mounted with no properly alignment. I will share my experiences about along yours.
Regards and enjoy the music,
Raul. |
Dear John_gordon, you don't really want me to tell you what additional breakdown torque is and why it does of course influence the skating force.
If you think skating force is just a phenomenon of friction and downforce - fine, certainly no problem with me.
If you muse about the model and draw yourself a good and precise force vector model of a pivot tonearm, you'll figure out.
I did suggest starting a "antiskating thread" - I didn't say I want to start it nor did I say I want to participate in it.
I have no questions regarding skating force in tonearms.
Regarding the UNI-Protractor and it's "universal" use.
Apparently you haven't worked with it so far and haven't understand it's principle either. Otherwise none of the comments in your last two posts would have been made.
You won't find a pivot tonearm on this planet which you can't align with the UNI-Protractor to best possible performance and any desired tangential curve.
If you think you can do better - go ahead design it.
So far your comments have shown little more than poor judgement, a fairly high aggression and very little understanding of the subject.
I welcome your attempt to put your name on the wall again and to prepare the road for yourself for a soon-to-be return to the audio market.
No problem with me - as far as I am concerned you are certainly welcome.
I might react to a post by you from time to time only, but so far very few actually did ask for an answer or a comment. Most were simply lacking content and seriousness. |
Dertonarm: you said If however the user does wish to align the given tonearm exactly to the geometry (especially the offset angle) the tonearm was designed with, then knowing the P2S and setting it precisely (IF possible ...) is important.
Important only if one wants to avoid an additional breakdown torque and thus another source for skating force in a pivot tonearm with a fixed offset cartridge mounting.
With tonarms like the Schroeder, Reed or Talea however we won't run into this problem at all. Didn´t you suggest starting an antiskate thread? But since you have brought the subject up, in what way do the Reed, Talea and Schroeder differ from other arms? The Talea and Schroeder appear to have a facility to alter the effective length,(as does any other arm with a slotted or movable headshell) and they have a facility to alter the headshell angle. What is the difference between this and altering the angle in a normal headshell? The Reed has a normal slotted headshell except for the model with its little azimuth adjusting device. What´s the difference? I would honestly like to know. And I am intrigued to know what are these mysterious additional breakdown torques which the above arms don´t have. Unless you can explain where else it comes from, the only torque acting to rotate the arm inwards is generated by forces acting on the stylus in reaction to downforce and friction. More downforce, more friction; more friction, more inwards torque. No downforce, no friction.; no friction, no torque. Using more downforce doesn´t make the inwards force disappear, just that the force acting downwards is enough to allow the stylus to track without distorting. The imbalance of forces on inner and outer groove walls hasn´t gone. John . |
Raul,
Could you please elaborate on this? I don't understand what you are trying to do by moving the cartridge forward or backward. Are you asking us to listen for different amounts of distortion from a cartridge that is no longer aligned properly? Thanks. |
Dertonarm: You said: If a phono protractor really is universal, it must automatically align regardless of the given mounting distance. I would agree with you in that, but I would disagree with you when you say that Setting the mounting distance is done before aligning the tonearm. It is a "conditio" already set before starting the alignment. This is only necessary when using a protractor which requires it - like yours - because, as you say, The UNI-Pro does follow the smart idea of Francis Dennesen and adapts to whatever P2S a given tonearm is mounted. As is the case with the Dennesen, arms with adjustable bases and fixed headshell mounts are awkward for your protractor. So it can´t really be called universal, as it only caters for arms with adjustment for effective length and offset at the headshell. In most cases the tonearm is already mounted when one starts to align the tonearm/cartridge All arms are "mounted" prior to alignment, but, as you are aware, not all arms have the pivot to spindle distance fixed at a specific measurement, but have the facility to adjust this, as in any arm on a pod or adjustable arm board, or the SME, and arms like it. It could be argued that a more universal version of the Dennesen would have adapted it to allow its use with arms such as these, as well as with different alignments. . |
Jazzgene, 'to bad Thorens ain't what it used to be'. I agree but there are many of those 'old one' second hand still demonstrating the value of simplicity in design: good platter, good bearing and an simple motor. Despite of
this fact the Uni-Pro on them looks to me like a King on
a donkey.
Regards, |
Dear Halcro: My mistake. That 15mm on overhang is not what help me but the distance between the cartridge stylus and the rear part on the headshell that if I remember is 50mm on some of my tonearms.
Raul. |
Dear Halcro: I don't think you noted yet. Several of my hedashell removable tonearms design have the manufacturer overhang spec at 15mm, I choosed on porpose due so many tests cartridge/tonearm combinations I have. This similar overhang characteristic help me to mount with almost none change any cartridge in any of those tonearms.
Yes, this is not exactly what you are talking about but an idea that could help.
Btw, now that you and other people are so in " deep " about cartridge/tonearm set up through accurate protractors seems to me adequate for you and every one that want to " explore " and learn on the subject to make a simple ( no money need it.! ) experiment:
- in one or two of your cartridge/tonearm combinations move the cartridge 1mm forward ( no protractor need it. ) and mantain the same cartrridge/headshell offset angle. After re-set the VTF and VTA/SRA and if you want azymuth and antiskate ( not need it for the experiment but if you want to be more " even " with today set-up. ) push the playback " button " and listen for a while.
After that and if you have the time and patience move the cartridge an additional 1mm forward and the same process but moving the cartridge 1mm and 2mm rearward.
Compare what you listened on those four different set ups against each to other and against what you are listening in your rigth now set ups.
IMHO this is a un-expected ( because the quality performance ) experiences where we could learn what is happening down " there ", I mean on playback against no-play status.
All of you that decide to " explore " in this " jungle " will be appreciated what you experienced.
Thank you in advance.
Regrads and enjoy the music,
Raul. |
Halcro
I haven't used it, but I'm sure you are correct in assuming a different principle for the Feickert. If it has the facility to set or measure mounting distance, it is because it uses arcs which have to be referenced to a known pivot point.
You are correct in saying that headshell type cartridges having no facility for adjustment need to have the effective length of the arm with the cartridge fitted known or measured. Also the true cartridge offset angle (which will depend on the arm/cartridge combination) also known or measured. Then an appropriate mounting distance can be calculated, and precisely set.
Alternatively, using an arm with a known alignment, you can use (if it has the same alignment) a two point protractor to set up. By sliding the base the offset will be given automatically. Swapping different kinds of these cartridges would depend on them having the same headshell mounting collar to stylus distance.
You are also right in saying that swapping headshells could be problematic. It looks to me that swapping headshells between arms would require them to be set up initially with one headshell/ cartridge combination which remained set once the first arm was done, and which was then used to set the remaining arms with adjustment achieved at the bases of the others, assuming they were different arms.
The alignment chosen would have to also be the same for each set up, irrespective of the arm design, but the arms could be different lengths. Then any cartridge/ headshell combination could be set up to suit these alignments without moving the bases. This would depend on the headshells having slots, though the initial headshell could have holes as long as the arm used was designed to the chosen alignment.
I think that covers most of the difficulties..... please feel free to point out a simpler way, any mistakes or anything I've overlooked.
John
.
|
I tried the Uni-Pro on my Thorens TD-316. I love this simple table and is my 1st table I bought as a kid. Got it new in the mid 80's.
I chose the Baerwarld IEC for this table which comes with the TP-21 arm. I used Benz Micro MC20E2 cartridge.
I had to level the spring suspension a bit after placing the Uni-Pro on the platter. No big deal. The cartridge had to be scooted all the way to the front of the headshell in order for the stylus to hit the point precisely. The Uni-Pro makes sighting the cantilever a simple procedure.
Listening to some Keith Jarrett LPs and I have to say, this modest table does hold quite well against my main table which costs much much more. It's been running just like new for close to 30 years with just a belt swap. Including several home moves! Too bad Thorens ain't what it used to be. |
Dear Daniel and John,
I accept that the majority of tonearms in use today are 'fixed' to their turntables and cannot be adjusted.
The accuracy of the positioning of these tonearms vis-a-vis the spindle to pivot distance is often not the greatest and I appreciate that the UNIprotractor achieves the correct cartridge alignment regardless of the accuracy of the tonearm placement.
Having said that however, I believe that the cost of the UNIprotractor can best be amortized by someone possessing multiple arms and often in such a situation, some of those tonearms will have removable headshells?
If each tonearm is 'inaccurately' positioned in terms of S to P distance, the swapping of headshells+cartridges between arms, will result in multiple accumulating errors......no?
Additionally, if one is using fixed headshell/cartridge combinations such as the FR-7 series or some EMTs, adjustments within the headshell/cartridge are simply not possible and correct spindle to pivot dimension is essential to extract the best performance n'est pas?
It is obviously ideal to have the tonearm set at the correct S to P dimension and an accurate method for achieving this is desirable. |
Good point here. That's the reason for the micrometer driven linear stage carrying the positioning arm - it sets "Y" precisely for whatever null point the specific UNI-template sets.
My initial thoughts when designing the UNI-Pro were similar.
If a phono protractor really is universal, it must automatically align regardless of the given mounting distance.
In most cases the tonearm is already mounted when one starts to align the tonearm/cartridge. Then there are a good many situations where the P2S simply can't be altered by the user (pre-drilled mounting hole, fixed armboards/plinth).
The UNI-Pro does follow the smart idea of Francis Dennesen and adapts to whatever P2S a given tonearm is mounted.
Setting the mounting distance is done before aligning the tonearm. It is a "conditio" already set before starting the alignment.
If however the user does wish to align the given tonearm exactly to the geometry (especially the offset angle) the tonearm was designed with, then knowing the P2S and setting it precisely (IF possible ...) is important.
Important only if one wants to avoid an additional breakdown torque and thus another source for skating force in a pivot tonearm with a fixed offset cartridge mounting.
With tonarms like the Schroeder, Reed or Talea however we won't run into this problem at all.
Cheers,
D. |
It does beg the question, though, of why one would need to know the mounting distance, as the Dennesen principle allows correct alignment with any existing and unknown mounting distance. If the distance has been set wrongly for a particular arm, this would be corrected (for a slotted headshell) by adjusting the effective length and cartridge offset (assuming enough adjustment) to match the null on the protractor. Thanks for that explanation John. Then the Feikert alignment tool works on a different principle where Spindle to Pivot distance and Overhang are critical to achieving correct geometry? Is that correct? |
As an aside: Halcro, you asked (16th April): although something tells me that whilst the UNIprotractor 'arm' is not centred on the Spindle, there might be some mathematical formula which, when the micrometer is wound down to its minimum position, could still be used to check Spindle to Pivot dimensions? I don't know how the device works, how it differs from the Dennesen, or what the various fine adjustment features are, but presumably they allow the device to be set up for Baerwald IEC nulls, (and whatever other nulls are supplied). If the principle is Dennesen, which it appears to be, then arm mounting distance (pivot to spindle distance) can be obtained by finding two dimensions: First: The distance to the arm pivot as measured along the axis of the perspex arm from the point where the null radius crosses it. Call this X. Second: The distance from the centre of the spindle along the null radius to the centre line of the perspex arm that terminates on the arm pivot. This distance varies depending on the alignment, and must adjust for each, but you don't have to measure it if the device can be set for Baerwald IEC as it is given by: Outer null minus Inner null, then divide by 2, Call this Y. (For Baerwald IEC this is 27.45. If the device is set for another alignment, then the same calculation applies with the appropriate nulls.) This gives a right angled triangle, so the mounting distance is given by: the square root of: X squared plus Y squared. This applies to the Dennesen also, of course, but only for the Baerwald alignment for which it is set up, unless modified. The accuracy of the method depends on how well you can measure the distance along the perspex arm to the pivot. It does beg the question, though, of why one would need to know the mounting distance, as the Dennesen principle allows correct alignment with any existing and unknown mounting distance. If the distance has been set wrongly for a particular arm, this would be corrected (for a slotted headshell) by adjusting the effective length and cartridge offset (assuming enough adjustment) to match the null on the protractor. . |
Dear Jazzgene, thank you for your impressions.
In the 2nd production run we will produce too a different version of the round reticle with black cross-hairs.
It will be much easier to read when spotting silver colored bearing houses.
This is available as an option side by side with the white engraved reticle that come with the UNI-Protractor ( which in contrary is easier to read on black tonearms).
Cheers,
D. |
