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Post by julesd68 on Mar 4, 2017 13:08:39 GMT
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Post by Mr Whippy on Mar 5, 2017 19:37:00 GMT
Unusual (and ungainly, to my mind). Would have thought it would be a source of noise or vibration:
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Post by ChrisB on Mar 5, 2017 20:00:40 GMT
It's not so different from the Garrard -Zero 100 arm or the Burne-Jones is it?
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Post by Mr Whippy on Mar 5, 2017 20:25:47 GMT
Suppose so Chris. Very little to pick between the two interpretations:
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Post by ChrisB on Mar 5, 2017 20:29:37 GMT
That one's got 6 arms!
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Post by MartinT on Mar 5, 2017 20:55:14 GMT
I was thinking the same thing. My favourite Pre-Raphaelite!
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Post by ChrisB on Mar 5, 2017 21:08:29 GMT
B-J Tonearm
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Post by ChrisB on Mar 5, 2017 22:55:58 GMT
How about a 16" Well Tempered clone?
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ynwan
Rank: Trio
Posts: 185
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Post by ynwan on Mar 6, 2017 20:03:06 GMT
It's not just down to rigidity. Two of the most rigid arms in the business are the Rega RB300 and SME V. They both sound grey and dull to my ears. I prefer the heavyweights like the Fidelity Research, Zeta and of course my own Dynavector. However, your turntable's suspension may not take any of these. The Jelco SA-750D is a good inexpensive arm and as near universal in application as possible. What are you paying for? Good materials, good engineering quality, fine bearings, fine tolerances. Well you raise an interesting question as to what is meant by 'rigidity' in tonearm design. Yes, both the designs you describe use a jointless construction between head shell, tube and bearing, but they are also both cast which gives a much more crystalline structure than drawn tube and milled from solid structures and will be significantly less stiff than such a structure (though better damped - at least at some frequencies). Another big question relates to damping and I would be careful in assuming better damping means better sound. One of the most effective methods of suppressing arm resonance is silicone fluid baths at the bearing (or headshell). However, every arm that offers this has sounded best with minimum, or no, damping (not just in my opinion but many others). Also, wide band and even damping is very difficult to achieve. Stuffing the arm tube may suppress some frequencies (but very little) but this may well cause other undamped frequencies to appear more prominent.
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ynwan
Rank: Trio
Posts: 185
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Post by ynwan on Mar 6, 2017 20:21:21 GMT
The pros and cons are simultaneously easy and complicated to describe/explain. On the plus side a well implemented unipivot will have consistent bearing contact at all times irrespective of orientation and stylus position. It will also have clearly, and measurably, lower friction than even the most carefully adjusted gimbal bearing arm and only beaten in this regard by a properly implemented air bearing (though that will have a considerably less rigid bearing interface). On the negative side they can be awkward to use in that they rock side to side. On a more technical level that apparent lack of rigidity can manifest itself as rocking modes within the audible spectrum. It is also more difficult to apply ideal geometry (not cartridge alignment) because gravity is loading the bearing (sorry, that's not well explained but I am typing on my phone and don't want to write an essay). Finally, it is less easy to apply additional forces (like bias) without affecting other elements of the bearings geometry.
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Post by speedysteve on Mar 6, 2017 21:50:42 GMT
"Aye, they have arms and legs enough between them"
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Post by MartinT on Mar 7, 2017 7:59:49 GMT
Well you raise an interesting question as to what is meant by 'rigidity' in tonearm design. Yes, both the designs you describe use a jointless construction between head shell, tube and bearing, but they are also both cast which gives a much more crystalline structure than drawn tube and milled from solid structures and will be significantly less stiff than such a structure (though better damped - at least at some frequencies). That makes sense. I am certainly more wary of apparent one-piece design as being the best kind of construction, just based on my own listening experiences. I also don't equate rigidity with strength - I well remember SME proferring an armtube at hi-fi shows, saying that they would give a complete arm to anyone who could bend the tube by hand. No-one could, of course.
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Post by julesd68 on Mar 7, 2017 11:43:50 GMT
The pros and cons are simultaneously easy and complicated to describe/explain. On the plus side a well implemented unipivot will have consistent bearing contact at all times irrespective of orientation and stylus position. It will also have clearly, and measurably, lower friction than even the most carefully adjusted gimbal bearing arm and only beaten in this regard by a properly implemented air bearing (though that will have a considerably less rigid bearing interface). On the negative side they can be awkward to use in that they rock side to side. On a more technical level that apparent lack of rigidity can manifest itself as rocking modes within the audible spectrum. It is also more difficult to apply ideal geometry (not cartridge alignment) because gravity is loading the bearing (sorry, that's not well explained but I am typing on my phone and don't want to write an essay). Finally, it is less easy to apply additional forces (like bias) without affecting other elements of the bearings geometry. Thanks for that information, very interesting ...
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Post by julesd68 on Mar 9, 2017 18:30:03 GMT
I think an Odyssey is the only arm I would seriously consider changing my Kuzma for, as it is the one arm that was designed specifically to go with my Source of course ... One has just popped up on ebay -
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Post by ChrisB on Mar 9, 2017 18:42:27 GMT
Nice.
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Post by pinkie on Mar 14, 2017 11:04:40 GMT
If I were buying again I'd look seriously at a (Syrinx) PU7 from J7 (Audio Origami). Very good value for around £2k for a custom made arm to your spec and finish. This and the FX3 would probably be on my shortlist. The syrinx looks beautiful. And doubtless performs well. For aesthetics and nostalgia I would be very tempted My introduction to pink triangle was in a small hi-fi shop in bexley or Sidcup to audition beyer electrostatic headphones since I was at uni and could not use speakers much. The test rig was a PT original (with slide switch) syrinx pu 2 and dynavector karat I think. But I find it sad after all these years that so much emphasis is on design style and engineering and so little on physics or innovation. It's a tube with a flat fixed headshell , conventional bearings and counterweight and it will be no shock if it sounds like one. I've probably jinxed this (again) but there is a real chance Arthur is finally going to exhibit ak47 at least, or just maybe F1 at Munich this year. They won't sound like a regular tube. If they actually get there, chances are they will attract rave reviews from press and distributors. And forums, without hearing them will assure fellow members they are not that special and will fall apart cos they have a friend who had a PT export once
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Post by MartinT on Mar 14, 2017 11:26:29 GMT
I'd love to hear Arthur's latest, Richard, and if it sounds as good as you suggest then I will sing its praises.
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Mar 14, 2017 13:41:39 GMT
I would also like to hear what AK can do in a "no holds barred" tone arm design. I really like the F.X approach, and if he can better that, it should be rather good. I could not justify buying one though...
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Deleted
Deleted Member
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Post by Deleted on Mar 14, 2017 15:58:02 GMT
I would also like to hear what AK can do in a "no holds barred" tone arm design. I really like the F.X approach, and if he can better that, it should be rather good. I could not justify buying one though... There is no way you would be buying a no holds barred tonearm design. The Swedish Audio Technologies may qualify but it will set you back close to £30K. Fremer has one and thinks it's the best but looking at the photos engineering content is similar to an SME 309 and it might even be easier to make. The high cost is more to do with a few being made by one man. Components cost far more in small runs plus high price limits demand to the low production capacity available at present. As far as SME being dead or grey sounding, that is simply not true of current production at least. I now have a 309 on Michell Orbe and would describe the combination as controlled but very musical. If it sounds grey it is likely to be poor synergy or non optimum set up of deck or arm. A bit of tweaking has certainly opened up the sound more. Bass is in DD class with plenty of treble minus an edginess apparent with many arms. The old RB300 could be a bit grey but having heard the latest P3 with RB330 the presentation is just the opposite verging on the clinical.
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Post by pinkie on Mar 14, 2017 17:10:42 GMT
I would also like to hear what AK can do in a "no holds barred" tone arm design. I really like the F.X approach, and if he can better that, it should be rather good. I could not justify buying one though... "No holds barred"? Can mean what you want. The AK47 is effectively the "bells and whistles" version of the straight F.X concept with an aluminium tube for that element. F1 is "no attempt to produce to a price" and "everything I want to try in an arm, without cost constraints". I think a price of £15,000 was mooted. For sure, that is to do with very small production runs, and very high R&D hours per model sold, rather than unobtainium or bling. I think it unlikely one will grace my illustrious deck either -even at mates rates. I am happy enough with what I have - although I would like to de-scruffy the PT unit which as Kevin knows, is in a very prototype state. Interestingly AK was talking in one of his upbeat moments recently of relaunching PT and suspendeds**. I take full credit for the thought troubling him - and am very grateful that he indulged an old mate to such an extent allowing me to explore the potential in the concept. If it turns into a new product line (or really an old one reborn) then that will be a bonus. I had it first! **There are lots of "maybe's" with AK. They don't all necessarily stay the course. There are a couple of refinements I would like to finish on the deck - and since AK and his partner are talking of coming to visit us in Granes, I can maybe bend his ear then.
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