Hi Jonathan,
I imagine though, that the 'processing' of the material and the 'significant effect on sound' due to that, would vary depending on 'where' in the signal-processing chain that material was applied?
For instance, I can imagine a tonearm headshell or arm-tube having a more 'significant' effect on the signal than say......an isolating spike or cone, or an arm-pod or a shelf bracket?
Cheers
Henry |
Hi Henry.
By building, listening and measuring, not only to my own designs and prototypes, but those of other designers also. Subsequent discussions with yet other audio designers and retired designers have suggested that we generally agree about the ranking.
Compared to machining, casting is cheap if large numbers of parts are to be produced, and therefore would be most attractive to a manufacturer such as myself. This is particularly true when the shapes get complex, which drives machining costs up, up, up. Unfortunately, so far I haven't been able to convince myself to use casting for anything more demanding than an active digital cable enclosure.
How many materials? Off the top of my head, aluminum(s), magnesium(s), brass(es), bronze(s), iron(s), copper(s), titanium(s), stainless steel(s). Probably more if I jog my memory.
BTW, none of the above necessarily means that you and I would come to the same conclusions. It very well could be that your audio system and listening habits are different enough from mine that we'd have to agree to disagree.
cheers, jonathan |
Dear Halcro, Jcarr's "table of material's sonic quality" is correct. The key is the decreasing ability/speed to transmit energy in the different processed materials. Cheers,
D. |
Thanks for the input Jonathan.
If I may ask.......how have you managed to determine this grading and for how many materials? |
Has anyone tried making their arm tower with brass? Do you see any advantages/disadvantages with this material?
Cheers |
IME, not only the choice of material, but how the material is processed has a significant effect on the sound.
Again IME, the descending order of sonic quality is: 1 machined from solid billet, 2 extruded into approximate shape then machined, 3 forged, 4 vacuum or pressure-cast, 5 sand cast.
I should also point out that the phosphor bronze alloys used in machining are different from those used for casting (higher tin and lead content).
hth, jonathan carr |
Hi Audpulse, If I am able to count this make at least two
man 'who has chosen the right material(s)'. But there are
others who have chosen for the 'acousticaly dead' arm pod
made as a sandwich from: two layers of steel,two layers of
cork, two layers of granite and one of acryl. This abundance of materials combined with the scientific reaserch regarding the acoustical death imply a different kind of animal. So it is more about the man than the material if you get my meaning.
Regards, |
That's what my armpods are made of.....phosphor bronze.
Sounds good to me ==========Halcro
Now that is a man who has chosen one of the right materials for an armpod. |
Dear Chris, If I understand Freud well this is how 'it'
should work: 1. first step is the denial (= your post);
2 second step is the doubt; 3. third step is insecurity
and 4. seling the demn thing to get some night's rest.
In the meanwhile I should be able to get a second 'nacked
TT'.
Sleep well till the second 'step'.
Regards, |
That's what my armpods are made of.....phosphor bronze.
Sounds good to me :^) |
Hi T Bone - An all Phosphor-Bronze POD ? |
Chris,
FWIW, a friend swears by phosphor bronze. |
If this advice follows the logic of Rauls recommendations
( not p but q)some of us will get fantastic arm pods for cheap. My only worry is the high cost of postage from Australia to Europe I already called dibs on those Nikola sorry right Henry ? Hi D I apologize should have posted my question in the Uni-Protractor thread about the tangential alignment tool. Chris |
Hi D Does your Uni tangential alignment tool differ from the manufacturers one at all ?
The tool I actually use for measurement is a customized one that has a fine thin line etched into the material. The stylus fits into it or it doesnt. The pic I posted was the manufacturers one as u know. Thought it looked like a nice two lane highway per post reference ? I have found with the sp10 chassis 7.5 inches is the "middle of the road" when measured from the left side for the ET 2.5.
Hi Lew if you choose to order the Kuzma 4 point tonearm online with a computer pls be careful when checking off the options boxes. You dont want to end up receiving one of Mr Kuzmas brass arm pods in the mail too ? But I have to admit I would pay to see a picture of your face if you opened up the box to find one inside? :>)
All
I am going to have a plate welded to the bottom of my brass arm pod to accept the DIN connection right at the pod. Can anyone tell me if I better off to use a different metal other than brass for this plate. (sonically speaking ) Anyone have any thoughts on this ? Was planning on brass ?
Much appreciated.
Cheers Chris |
Dear Daniel,
I understand your point about 'fixing' the base via tape or blu-tak and that is easy to do.
There is however another philosophy to the 'support' of the armpods.....and indeed the nude TT itself......and that is, to de-couple both elements from structure-borne feedback via the supporting shelf.
I know some folks insist that spikes actually 'couple' rather than 'de-couple' and that 'isolating' feet made of rubber or visco-elastic material are better and there may be some truth in that. Nevertheless, I believe that bolting or fixing the armpods to the substrate without 'decoupling', may cause problems from structure-borne feedback?
It may not be a big deal in the overall scheme of things....so let's keep our minds open :^)
Cheers
Henry |
Dear Henry,
it is not disputed at all - at least not by me - that a "nude" turntable paired with an "isolated/free" armpod(s) can sound very good.
For a limited period of time.
With certain arm/cartridge combination (the higher the compliance - the better).
Even I have tried separate arm pods as long back as 1986 (if I remember right they were pretty hefty - approx 30 lbs each) in conjunction with a Le Tallec and a Micro Seiki skeleton TT.
Neither Lewm nor I do offer opinions based on theories here.
What we did was acting as advocati physici.
Technically - and ultimately sonically - there is no single advantage of isolated arm pod versus firmly attached armbase.
If isolated arm pods can and do - undisputed by me - sound so good in comparison with so many plinth-based tt, then the explanation is easy, logic and showing that there still is a lot of work to do in many integrated turntable concepts.
In any case - where is the problem, why not simply prevent an isolated arm pod (but by all means do at least place arm pod and tt on the same ground/shelf, whatever ) from moving by means of adhesive tape or similar.
Easy to remove, easy to alter.
But it is not just "movement" - it is too energy transfer and reflections.
That's why it works comparatively well with high compliance MMs - they but very little energy into the tonearm.
Peace on earth .....
Cheers,
D. |
Dear Lew, I expected some euphoria about the victory of your galleons. But instead your are chalenging my nationalistic feelings. Slovenia and Kuzma are my ex brothers and I already own Kuzma's TT. There are boundaries to any kind of tolerance,you know.
But If Kuzma offered one for free as a token of our reconciliation I am willing to (re) consider my tolerance.
Regards, |
If this advice follows the logic of Rauls recommendations
( not p but q)some of us will get fantastic arm pods for cheap. My only worry is the high cost of postage from Australia to Europe.
T_bone, Everything seems to be better in the USA. This of course apply also to the cats.
Regards, |
Dear Lewm & Daniel,
We are all thick-skinned enough to take the occasional barb :^)
I started this thread because of my surprise at the results of both the 'nude' DD turntable approach and the isolated 'armpods'.
They far exceeded my expectations and the implementation of both approaches is relatively easy for others to try.
So far, we have seen no negative responses from anyone who has actually sampled the approach but we have several 'naysayers' who haven't?
It seems rather odd to be offering opinions based on 'theories' when the 'proof of the pudding' is so easily abled to be sampled?
Rather like commenting on a cartridge without having heard it?:^) |
Dear Ct, Henry, and anyone else who is disturbed by my occasional digs at your approach to tonearm mounting: Believe me when I say you have my blessings in whatever you do, and I enjoy reading about the construction of the various pods. The fact that I have not tried it and may never try it is not a sign that I am a troglodyte; it merely shows that my plate is very full with other projects that have to take precedence, not to mention going to work every day. Altho you know quite well my theoretical objections to arm pods, which are largely the same as Dertonearm's, I am sure that an outboard arm pod can sound perfectly wonderful. I also think all of us can tolerate much more in the way of imperfections in our music reproduction than any of us cares to admit, so I doubt I would hear it if my arm pod were to "walk" a few mm in one direction or another with respect to my tt. I am very happy with what I have in the way of tt's right now.
Nandric, Did you tell me that you own a Kuzma 4-point tonearm? After reading Fremer's review, I am interested in that device. |
Nikola,
If cats only have seven lives in Holland and you need a few extra lives out of your cat, you need to import some from the USA where they have nine. |
Dear Henry, dear Chris, dear Nikola, "such passion" - really?
I rather perceive this tread and discussion about the pro and cons of "free" arm pods as being moderate and kind of "in cool ( if not cold ...) blood".
In any case - I certainly do not want to discredit the whole topic and the " free arm pod" pro-camp .
Everything is fine, as long as a separate arm pod is used for a limited period of time and/or to test a given tonearm quick and without drilling mounting holes in a precious plinth.
Aside from the "relative movement", there are other issues going with - any - separate arm pod ( energy transmission and reflections et al ).
Given equal care and smart design, a separate arm pod will ( .. sorry about that, Texas! ...) be 2nd choice - quality-wise ( if - of course - more convenient ).
It nevertheless has it's merits and does ease tonearm testing.
The armboards originally invented by Micro Seiki and copied by many others since can be seen as "cantilevers" - but at least they keep strict distance.
The molecular point of view is not applicable here - the derivations in atomic structure and surface are there in any case.
We have to cope and deal with them anyway.
This however does not affect the relative movement of two fairly lightweight bodies (everything is lightweight here - everything under a ton ) relative to each other caused by building resonance and energy transfer - sorry, but these are different "animals".
Furthermore these movements aren't in Microns nor Angstroems - they can approach 1/100 mm and more quite fast.
If we might not "detect" it by worsening sound nor derivation on a tangential template which line is already 1 mm thick does not alter nor deny the physical phenomenon.
A free arm pod will wander - so why do not use a adhesive tape to secure it in place ?
Easy to detach again and eliminating - or at least lessening - the "relative wandering".
Best,
D. |
Dear Chris,'Such passion over a hunk of metal.' You should
check the gold price at present. BTW never heard about fetishism?
Regards, |
Just wanted to add from my direct experience and conversations with other people that use PODS. Most do not have 4 pods set up ready to go like Henry does.
So others change these PODS in and out with different tonearms and cartridges frequently - weekly to monthly for some who prefer certain tonearms/cartridges with different music.
To these people - aligning a tonearm/cartridge on a pod takes literally all of 1 or 2 minutes. You move the whole pod around till its lined up. Hence their popularity, flexibility and advantage, regardless of the better sonics being discussed here.
So IMO - the theory of these microscopic movements never comes into play here. Its a moot point based on the vinyl POD persons habits.
I can also add from my direct experience and I know that D is aware of this. Unlike a pivot arm - a linear tracker tells you right away if something is out. In fact it screams it. If it is not dialed in, it is like watching TV in the old days with an antennae remember the haze around the image until you moved the antennae around to get the image clear.
Cheers Chris |
Such passion over a hunk of metal ! Is this not a great hobby that can generate this much passion over an inanimate object.
Dear D, Lew - I realize that Henrys pods do kind of look like little gods in the sun but trust me they are not real. This is not Greek Mythology. They don't get up in the middle of the night and start dancing together.
No - Something tells me there has to be more to this to stir up these emotions because building one is not rocket science.
- Could it be egos ?
- Could it be religious in nature ?
- Could it be this POD changes our way of life ?
- Could it have an impact on my business $$ if it becomes mainstream in this hobby ? Ouch that one hurt.
Pick one or make up your own because I really dont get what the commotion is all about.
For those of us that use them they bring better sonics, flexibility, choices we never had before.
"Excuses", at this point, are just a mask for some form of bias or denial. Arthur Salvatore |
Dear Daniel, I thought so but there is a proverb in Holland : 'the cat has seven lifes' which may imply exclusion of the number 8. Some concessions reg. the 'real life' look to me as reasonable. Ie I still think that Kant was to severe as well as to optimistic.
Regards, |
Brad,
Corby's response to my concerns shows that he has an understanding of structural rigidity and its limitations.
His centre cantilevered vertical 'pole' being solid rather than a walled tube, and extending well down into the bottom solid pod imbues the structure with vastly stronger rigidity than I otherwise imagined?
Of course, the cantilevered arm-fixing plate is still a weakness which Corby realises.
Bear in mind that many turntables employ the same cantilevered metal armboards incl. Raven and Micro Seiki.
They can be rigid enough........as long as we don't get into sub-atomic movement? :^) |
Dear Nikola, I died many times for the absolute truth and will most probably continue to do so.
My problem with gravity is that I never managed to overcome it in the sense of Douglas Adam's "Hitchhiker's Guide"-Circle...... ;^) .....
The "cruel mistress" on the other hand never becomes boring nor loosing it's grip on my senses and interest ( remember Winston C.'s famous quote ? - "I've never been bored...").
Kant was a human being ....... so in his sense of conjunction of human kind...;-) ...
Cheers,
D. |
Halcro, your decription of Corby's armpod stability being questionable due to the amount of cantilevers involded surely contradicts your above response unless I am missing something.
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1294870073&openfrom&468&4#468
Brad |
Of course Dertonarm is right that there are
. almost constant movement in microscopic dimensions of which we are not consciously aware.
How does that affect the ouboard tonearm pod in the Copernican turntable system?
Firstly lets look at the manufacturing tolerances achievable in the real world:
Some of the tightest tolerances available are +/-75 microns (a micron being 1/1000 of 1mm).
On the microscopic level, a molecule is measured in Angstroms (1/10,000,000mm), whilst an atom is approx. 1/1,000,000,000mm.
Now imagine the platter of your turntable, machined to the tightest tolerances of flatness and roundness with the tightest tolerances of spindle centring available?
In terms of molecular and atomic accuracy, the platter will deviate from perfect flatness and roundness by millions and hundreds of millions of molecules and atoms, whilst the centre of the spindle will be millions of atoms off-centre.
The record of course, not having its centre hole or overall diameter even remotely close to +/-75 microns in accuracy, will be wobbling its way around the spindle with gaps between its centre edge and the spindle itself, measuring hundreds of millions of molecules wide.
This manufacturing INaccuracy is repeated throughout the tonearm and its bearings which are slopping and rattling with gaps millions of molecules wide whilst the deflections and movements in the tonearm on the molecular level, resemble slow-motion images of earth-quake affected suspension bridges.
So worry if you must, about the microscopic movements being inflicted upon your turntable system
.but fear not for your proudly sitting outboard tonearm. It stands solid and immovable (the more mass the better) and the accuracy of your tonearm set-up will remain unchanged month after month as evidenced by we, who actually have them, can testify. |
Dear Daniel, What an suprise. I thought that you are 100%
Kantian. Ie ready to die for the 'absolute truth'. What is
wrong with the gravity? Some problems with your TT design?
We all, I think, have some peculiar problems with what you
call a 'cruel misstress'. We are the human kind and this means
not nesessarily the Kantian kind.
Kind regars, |
Dear Nandric, - yes, science is a cruel misstress and the physic laws which apply to the circumstances on this particular planet aren't always to my liking too.
I really hate gravity for instance ...;^) ....
Cheers,
D. |
Oh my, oh my. I 'see' Lew for my 'mental eye' shouting:
'I knew I was right with my galleons!'But my position is different. I at last 'grasped' what the religion is about. But if anybody is free to choose his own religion and even
his political preference, why should this be different with the 'world outlook'? My quess is that some very strong feelins are involved. Well I care much about my armpod.
So if the 'heliocentric world view' or the Greek orthodox kind of religion to which I belong by burth, is more accomodating than my choice should be obvious. But it hurts
when someone who you regarded as a friend can do such thing to you. I think that Kant should be blamed for this.
Regards, |
Dear Chris, "I rest my case as Nikola would say''? I 'would' if I was able to to understand the connection between the 'mathematical symplicity' of the tonearm geometry and the actual state of affare in adjusting the damn thing(s). So I started a separate thread to please some German friend of my as well to 'enlighten' the 40 years of 'darkness' in my life. As Halcro 'would say' the 'heliocentric illusion'.So I am waiting for the promissed
lecture or/and enlightment.
Regards, |
Hi Chris,
Glad to see that you have mastered the A'gon 'Link' bracketing system :^)
Not very easy at first?
Cheers
Henry |
Dear Lewm, while tonearm alignment in general is the most critical mechanic-related topic in the whole audio periphery, it is even more critical in the "outboard arm pod".
We like to think that if we do not "touch" the arm pod nor the tt by accident, the distance between the pivot and the spindle will stay constant if the arm pod has any decent mass.
Unfortunately this is not the case.
The "eigen"/resonance frequency of the two different masses in relation to each other will inevitably cause a movement between the tt and the "free" arm pod.
Or mechanical world isn't as quite and stable as it seems to the mere eye.
It is a bit like the nice example with old church windows.
Glass is a liquid not a solid. It just appears to be solid, because it is moving so slowly, that we can't see it.
The movements of arm pod (separate and not fixed to the solid ground) in relation to the turntable is ever so subtle ( at least in our awareness ..), but there is almost constant movement in microscopic dimensions.
Now the polished area of the stylus itself, as well as the most subtle modulations in the groove are already in the scale of 1/1000 of a millimeter.
You stepping on the ground while walking, a car passing by your house, the slamming of a door, a truck passing 3 blocks away from you - all this and much more is causing movement of your "free" arm pod relative to the turntable and as such a movement of the pivot in relation to the spindle.
Nothing apparent to ou eyes at first glance of course.
In addition, there is the chain of mechanical "detonations" by the tracking process of your stylus in the groove. It puts energy into tonearm, arm pod and turntable - all causing movement.
The energy of the tracking process is causing resonance and stimulating movement.
All this is subtle and you most likely won't notice anything.
With an electron microscope you would even see and could measure the movement. Not linear nor in a particular direction.
A "free" arm pod is what it is: - free ..... to move.
Forced by nature.
Cheers,
D. |
Dear DT, It's relevant to this thread only in that it points out the critical nature of tonearm alignment for those who wish to use outboard arm pods that are free to move about in relation to the tt spindle. (I will now don my armor plating.) I totally agree Lew that where the stylus "hits the road" is the most important thing for tonearm alignment. And after reading the last half dozen posts here about pivot arm stylus "driving problems" it really doesn't get any easier than this. IMO "I rest my case" as Nikola would say ? Stylus on the Road :>) |
The Dynavector DV-505 (and its later 507 version) has alway enticed me because of its distinctly architectonic appearance?
I have never though, read a really thorough review of its performance vis-a-vis other tonearms?
It would be good to hear your impressions? Hi Henry I will be posting tonearm and drive impressions on my system page. BTW - I thought that was a very interesting comparison of the Raven 3 motor BD versus JVC DD you did on your system page. I did a/b the DV505 with the ET 2.5 on pods already using the sp10 which I believe the dv505 was designed for. The dv505 was not using the same cartridge as the ET which had the empire 4000 diii gold on it. So I will hold off on what I heard. I am waiting for another empire cartridge from a member here but the delivery got botched up so I am still waiting for it. Thought I would have it in time for when I got back from vacation. So - for the older thinkers out there I mounted my second ET the smaller brother version 2.0 on the Lenco along with the Dv505. Lenco 75 Dv505 Et 2They will both be using Empire 4000 diii Gold. If it does good against the 2.5s little brother will try it against the ET 2.5 again. Mechanics, magnets, strings and funny hanging stuff up against a frictionless air bearing linear tracker. Lew - do you have the Dynavector stylus / spindle alignment gauge? Cheers Chris |
Lewm: I hope that armor plating doesn't shield you from the truth, because here's some coming at you.
I aligned my cart with a Mint protractor around a week ago. Your post and my previous concerns prompted me to check alignment just now. It's dead on. I used a 10x loupe. I must say I'm slightly surprised by this, but in my mind this is pretty conclusive as to the stability of the Copernican system. |
Dear DT, It's relevant to this thread only in that it points out the critical nature of tonearm alignment for those who wish to use outboard arm pods that are free to move about in relation to the tt spindle. (I will now don my armor plating.) |
Dear Nandric, dear Lewm, I am happy to talk in length about tangential curve and tonearm(s) "on their own", but we should do this in a separate thread.
Because - IMHO - this will soon leave Copernican view and separate arm pods ....
So much for now - no, you can't choose your zero points freely (at least not on a 12" record ...) - not if you want any decent positive results from tracking the signal in the groove.
Cheers,
D. |
Dear Lew, The math was alas my worst subject at school
but I thougt in terms of 'variables' and 'constants'in this context. I know that the term 'variable' has no sense in the math (thanks to Frege)but we are used, so to speak,
to use those terms. Well if we are free to choose the 'zero points' as we like or depending where we want the the least distortion than this means to me something that is 'variable'. So consequently there must be 'something' which should be constant. So I thought that
this must be the tonearm 'on its own'. I am sorry for my terminology but that is what I thought. From your statements I 'see' or deduce that we have no choice at all in the sense mentioned. Ie the designer of the tonearm in casu predeterminated our 'choice' in advance , so to speak. Ergo we have no 'free choice' at all? What an hobby!
Regards, |
Dear Nandric, In regards to your post of 08-10-11, I think that the maker of the tonearm, by selecting the offset angle of the headshell and by selecting an upper and lower limit for effective length (the margins for this being equal to the length of the parallel slots in the headshell that permit fore and aft movement of the cartridge), has pari passu selected for us an optimal geometry. We (the end user) are largely denied the luxury of deciding for ourselves where we want our null points with respect to innermost vs outermost grooves. Unless of course one wants to put up with distortions created by forcing an inappropriate geometry to be made to "work". In my experience of N=1 it is best to go with the tonearm designer. |
No. I will stick with Stevenson for DV. In fact, this experience (Baerwald vs Stevenson on the DV505) was a good lesson for me on the importance of geometry.
And now, back to your local Copernican view. And as Thuchan says, "all in fun". |
Dear Daniel, I don't like to use the 'Greek way out': knowledge beginns by knowing to not know. My point is much more simpler. If you know that you are ignorant about something you should ask questions and not bother about your own 'knowledge status'. Because I got the impression that we are free to choose where we want the least distortion on the record radius, irrespective of the tonearm kind or lenght (aka 'zero points') I thought that
the tonearm design and its 'own geometry' is, say, a 'different animal'. I still remember this issue about the 'optimal effective lenght' of the FR-64S. Was Ikeda san wrong, the user manual or who or what? In the same article by Kessler/Pisha I read: by the overhang of 15mm the only effective lenght that will be optimal is 274 mm, a lenght larger than many TT bases can accommodate. The authors also refer to Bauer and Seagrave (56/57) and not only to Bearwald btw. I have no idea when first stereo LP
was produced but assume, after reading you contribution, that their basic premise was Bearwald from 1941. And then to think , as I deed, that after my high school I was liberated from math. for the rest of my life.
Kind regards, |
Dear Lewm, youe assumption is correct - the Dynavector tonearms are designed following Stevenson IEC calculation. Stevenson IEC was pretty popular among japanese tonearm designers in the 1970ies and after.
While I am not really a fan of the Stevenson-curve (very high derivations in the last 3rd of the groove - then steep nose-diving to zero on the IEC/DIN standard point of inner groove limit ) - it has some merits.
But substituting Baerwald with Stevenson is jumping out of the frying pan and straight into the fire. Before going for Stevenson IEC, I would rather try Baerwald DIN or UNI-DIN instead - even with a Dynavector.
Cheers,
D. |
Dertonearm. Yes, before your protractor existed I had aligned my DV505 on my Lenco using Baerwald. The cartridge had to be twisted inward in the headshell, and the sound was not so good, which I tended to blame on the cartridge, since it was my first time hearing the Lenco, the DV505, AND this particular cartridge (which I think was the Ortofon M20 FL Super). However, when I finally found a Stevenson protractor (for free on Vinyl Engine) and used it to re-align the cartridge, things got a lot better. I concluded that the DV505 was designed for Stevenson or something very near it. |
Dear Nandric, dear Lewm, the japanese tonearm engineers of the 1970ies and 1980ies did not at all sign up to the Baerwald tangential curve.
At least not the majority of them.
And for some good reason.
They realized pretty early, that the situation for a stereo stylus is different and that the decreasing groove radius towards the inner label becomes more and more difficult.
Thus we see a lot of classic japanese tonearms with geometries pointing more toward Stevenson and in general more toward DIN-standard then IEC.
I won't say it is "better", but I would say that there are good reasons for not following the way of the "average lowest distortion".
Having an eye of where the maxima and minima of the derivation from tangential zero error are in fact located can bring interesting results.
In the western audio hemisphere it was/is - in general - all Baerwald/Loefgren A (with very little Loefgren B ..).
The fact that Loefgren A/Baerwald was calculated when no one dreamed yet about a stereo stylus is seldom mentioned today.
There are calculations which can indeed give lower average distortion as Baerwald - especially when tracking a stereo groove.
Cheers,
D. |
Yes. Love my DV505 so much that I have two of them. And then on top of that a dear friend (my longest term audiophile friend) gave me his DV501 last year. The DV501 was introduced shortly after the DV505. It is very like the 505 except that it lacks a few doodads, so it could be marketed for a lower price. DV501 uses counter-weight balance instead of dynamic balance, lacks the little spring-loaded resonance-reducing gizmo that is tucked up under the horizontally pivoting part of the 505 and 507. Some liked it better than the DV505. I preferred DV505 to 507 because the 505 can be surface-mounted; you don't have to drill a hole in your armboard or plinth to accommodate a vertical shaft that goes below the top surface of one or the other. When I built my early slate plinths, I decided to limit myself to surface-mount tonearms so as not to have to implement removable arm boards. The fully developed Mk3 plinth does have a removable slate or alu armboard, however, can use any tonearm of 10 or more inches effective length. |
Hi Chris, According to Kessier& Pisha ( Tonarm Geometry and
Setup; Audio,January 1980) some Japanese tonearms were not
optimaly designed .Ie in the sense of 'optimal geometry'.
Dyna DV 505 : the offset angle is 21.500 while the optimal is 22.814; the overhang is 15.000 while the optimal is 17.164.
Lew mentioned some problems with the adjustment of his DV 505 but in the
context of Baerwald, etc. To my mind the 'zero points' are
about our preference regading the question where on the
LP radius we want the least distortion. But I will gladly let
the (possible) technical implication to Dertonarm, Halcro, Raul and others.
Regards, |
