When the stylus is riding in the outer grooves
moving toward the one instant when it is tangent to the groove, the
tracking angle error is getting narrower until it disappears momentarily
at the point of tangency. Then the stylus keeps on riding toward the
inner grooves, which is opening up the tracking angle error in a
different direction until it reaches another maximum at the innermost
groove. This would also change the direction of the skating force.
No, this is mistaken. Skating force is mostly a function of VTF and offset, not groove radius. The force doesn't change direction, but is always pulling the cartridge towards the center of the disc.
Addendum. Upon further thought, I do see your point about the skating force changing direction. When the stylus is riding in the outer grooves moving toward the one instant when it is tangent to the groove, the tracking angle error is getting narrower until it disappears momentarily at the point of tangency. Then the stylus keeps on riding toward the inner grooves, which is opening up the tracking angle error in a different direction until it reaches another maximum at the innermost groove. This would also change the direction of the skating force. My remaining point would only be that by my calculation, the max tracking angle error for underhung tonearms like the RS-A1 and the Viv is much greater than for conventional overhung tonearms. Yet, with my RS-A1, I don't hear it at all. In fact, the RS-A1 paints a smoother more coherent picture across the surface of an LP than do most overhung tonearms. That is what makes me wonder if the real "problem" with most tonearms vis a vis skating force is created by the headshell offset angle.
Racedoc, did you actually make quantitative measurements of skating force? Or are you reporting your observation of what the tonearm does on a grooveless LP? In any case the skating force will be a function of the friction of the stylus in the groove and the angle of tracking error. There’s no getting away from the calculation. I do question the importance of skating force generated by by tracking angle error. The possible benefit of an underhung tonearm like the viv float is that there is no headshell offset angle which also generates a skating force that is additive with tracking angle error, at points on the LP where the cantilever is not tangent to the groove. And by the way examining skating force on a grooveless LP is fraught with sources for error. There is much less friction on a grooveless LP for one thing.
Finally, I am not sure I understand your first sentence where you say that the skating force changes direction with the viv float. Can you explain further?
I have heard many fine systems utilizing Koetsu cartridges, but, I cannot say to what extent the particular tonearm contributed to, or detracted from, the sound I heard. A local dealer that is particularly fond of Koetsu cartridges likes the Ortofon RS-309D tonearm (12" tonearm that can accommodate a SPU-type headshell).
@lewm The skating force changes the direction using the ViV Rigid Float.
At the "lead-in groove" (the start of an LP) there is a very weak force to the inside. Most of the part of an LP there is no noticable force (even with a flat / non-grooved platter no movement). At the "lead-out groove" (the end of an LP) there is a very weak force towards the outside.
In average the skating force is negligible compared to a "normal" tonearm.
I ran a Blue Lace on a 12" 3DR arm, worked but far from optimal results. You can purchase a great condition FR-64S for $2500 that works excellent with Koetsu.
Racedoc, This is in response to your post of 10-13-2017. Therefore, you may never see it. I am not sure exactly what Peter Ledermann may have told you regarding skating force and the Viv Float. But it most certainly does generate a skating force at all points on the LP surface except that one point where the arm wand (and presumably the cantilever/stylus) is tangent to the groove. At that instant, skating force = 0.
Conventional tonearms can achieve tangency to the groove at TWO points on the playing surface of the LP, which is the whole reason for stylus overhang and therefore headshell offset angle. However, even at those two points of tangency, there will still be a skating force, due to the headshell offset angle.
What the Viv and the RS-A1 may be telling us is that our obsession with tracking angle error is misplaced.
@bogeybuster49 I know it’s been done, and I haven’t tried it myself, but my instincts are going hard against that one. You want heavy mass and rigid bearings -- neither of which the VPI arm seems to provide, though the new 2nd pivot might help.
You really don’t see any VPI arm owners extolling the virtues of Koetsu. That says a lot.
Also, maybe unrelated -- back when I ran a SOTA Star as my 1st table, I almost bought my dealer’s VPI arm to mount on it, but SOTA told me in no uncertain terms that was a BAD idea. Suspensions and VPI don’t mix either.
I recently tried a Koetsu Jade with my Clearaudio Universal 12", and I’d say that arm is a no-go for Koetsu. Dynamically flat, a bit dead, definitely lacking the passion associated with Koetsu. However the Universal does very well with a Shelter Harmony; better than even the Graham for that cart.
The Graham Supreme and Fidelity Research FR64fx are far better matches for Koetsu. I also had an opportunity, several years ago, to purchase a mint Koetsu SA-1100 tonearm locally. After inspecting it in person, I passed -- the build quality and feel of my FR64fx far exceeds the SA1100 in every way. It was obvious to me, even then, that the Koetsu arm was a Jelco build. Cool head-shell though!!
I have the 9"-version in my system. Due to the underhang the "mounting distance" is with 273mm quite long and it looks not really short.
Fascinating is that some friends and me have played around with a huge variety of different cartridges (weight, quality and compliance) and there was not one cartridge playing not better than in other high end tonearms. (Ortofon 2M, Ortofon Vero, Ortofon Cadenza Black, Ortofon SPU, ZYX 4D Atmos, DS Audio DS-W1, DS Audio DS-002, Koetsu Rosewood and others).
The arm has no antiskating function. But this is not necessary, because the maximum skating force is exactly so strong than with a conventional arm and perfect antiskating adjusted. (According to the advice of Mr. Lederman)
idl57, It's not surprising that the Koetsu tonearm did not float your boat. Upon close inspection of photos, it appears to be a Jelco tonearm in Koetsu guise, which of course raises its cost by a factor of 2 or 3 compared to a Jelco 750. Not that Jelco tonearms are "bad" per se.
racedoc, Can you say more about the Viv? I was in Tokyo a year ago and lingered in Yodibashi Camera in Akihabara for more than an hour deciding whether or not to buy a Viv. They had all 3 sizes on display (7, 9, and 14-inch) Which do you have? I calculated that tracking error goes down significantly when you go from 7 to 9 but from there going to 14 doesn't help enough to warrant the extra length, possible issues with resonance, and the difficulty in mounting. I would have bought the 9-inch, had I gone ahead with purchase. My interest in the Viv is based on my own home experience with one of the only other "underhung" tonearms on the market, the RS Labs RS-A1. That tonearm is also more excellent than one would want to believe it is by just looking at it. This led me to believe that underhang is a serious alternative, that tracking angle error is not such a big deal (because both underhung tonearms develop a lot of tracking angle error as they traverse the LP surface, more than with any overhung tonearm). By inference, this also suggests that headshell offset angle IS detrimental to maximum fidelity. (For others, the headshell on an underhung tonearm is not offset at an angle to the arm wand.)
I never forgot that Koetsu midrange . I am wondering about the arm match. I certainly will not back cue or scratch, it’s just for playback. I do want the ability to swap headshells.
Much like David Mancuso (RIP) who DJ’ed with pair of Koetsu. Are you gonna use two? Where on earth you have a place to spin records on public with set up deserved Koetsu quality (apms, speakers etc), in Japan?
Why not take an empirical approach, begin with a low mass arm, and measure the cartridge/arm resonant frequency, and add mass to the arm as needed until you hit the optimal range of 9Hz to 10Hz?
I had a Classic Red and a RSP on the Da Vinci Grandezza arm. It worked great. I also had the Classic on a Linn Lp12 with Ekos arm and it worked very well also.
jsl57, that's an interesting response. Actually, I can easily believe it to be true! The Ekos is an arm that I think does well with slightly heavier cartridges and I think tends to be quite able in the bass, which would seem to jive well with Koetsu's. I wonder how the Ekos SE would fare?
I have used a Koetsu for most of my audiophile life. I still have a Rosewood Pro IV, the last great cartridge from the old man Sugano.
I have used it on many different arms over the years, although not the Graham/Triplaner/insert name of stupidly expensive arm here. I even bought a Koetsu arm thinking that would be the ultimate. It was the worst. My final solution for this cartridge will be controversial, and disliked by many.
The arm: Linn.
I may be the only person on earth that uses a Linn arm on a non-Linn table. I bought a used ITTOK just to try it out. The Koetsu LOVES this arm! It loved it so much, I bought an EKOS, as it is the ultimate ITTOK.
I am running a Koetsu Urushi Gold in an FR-64fx. Works great. I was told by a long lost friend at Sumiko that Koetsu's were originally designed by Sugano for FR tonearms.
I also have a Sumiko MDC-800 and it does not work as well with the Koetsu as with the FR. The MDC-800, with a 3g headshell weight, works very well with my Miyajima Shilabe. Both are low compliance cartridges - so go figure.
As my friend Raul often points out - putting a cartridge and a tonearm together is like a marriage - it can go great, or it can cause you to tear your hair out, and the only way to find out how it's going to go is to try it. Spec.s only tell you so much.
I have a rebuilt ( from Koetsu ) Rosewood. Two tonearms. One a Moerch DP8 ( 12 inch, blue armwand ) Two a Fidelity Research FR66s. Various headshells. The best fit was the Arche w/ silver leads.
The Koetsu sounded sublime in both arms. If I had to pick a winner, it would probably be the FR66s.
Now I'm not saying the FR66s is better than the Moerch. But with the Rosewood, it is to my ears. The Moerch, I think, bettered the FR66s with some other cartridges.
But both were superb performers with the Rosewood.
I’ve used various Koetsu cartridges (Coralstone Plat, Jade Plat, Onyx Plat, Onyx Sig, RSP) between a Fidelity Research FR64fx and Graham Phantom Supreme 10". Both arms pair great.
Thanks, Raul. I got the idea that Koetsu's in general have very low compliance from what I have read on the internet, always a dangerous way to gather information. I ran my Urushi in a Triplanar, which is medium mass; it "worked" fine, but I've never tested higher mass tonearms. If it's really medium compliance, it ought to work fine in a Triplanar and in any of several other modern high end tonearms that typically seem to shoot for "medium" effective mass.
Dear @lewm : In reality is not a low complianc but belongs more to the medium compliance range. Its 5-6cu is at 100 hz, so its real cu is more in the 10-12 number.
It's not at all hard to believe that the 1200GAE is an "audiophile" turntable, and for the Koetsu, which has low compliance, you would use a tonearm with high effective mass. How high? I would say start at 12-15 gm and go up from there. Some have said that the Fidelity Research tonearms are a great match; those have effective mass >25 gm.
it would seem to be hard to believe that a Technics 1200GAE is an audiophile table, and while not quite as good as my old Goldmund Studios with T3f with its midbass detail and full wave launch ...shockingly it is pretty good, much preferred to a Linn or all VPI takes a back seat to the new Chronos. I want this table to do double duty. Part audiophile and part audiophile DJ. It bears no sonic haze and lack of bass detail and flat midrange soundstage like a regular 1200MKII OR 1210MG5.
I had a Koetsu Rosewood ( in 1987) on a Mitsubishi LT-30 (I still have one of these too) and the Bass was lacking , and mid range was bloated I assume because of a cartridge mismatch to tech table. I ended up using a Monster Cable alpha 2 which I think was a ZXY cart.
I never forgot that Koetsu midrange . I am wondering about the arm match. I certainly will not back cue or scratch, it's just for playback. I do want the ability to swap headshells.
Fellow enthusiasts; Re: Koetsu Urushi compliance spec 5x 10-6cm/dyne;this is relative to 100hz; the compliance spec as quoted by a Koetsu Dealer in USA is 10x10-6cm/dyne relative to 10hz.Clearly low compliance. This is a dynamic spec of compliance, definitely not static compliance which is much higher.This latter compliance spec is what should be used when calculating arm/cartridge resonance figures from the available tables. The SME& ORTOFON sites provide excellent info on the relationship of cartridge compliance/arm effective mass and other important factors which relate to performance. The Koetsu Urushi Black cartridge( I have 2) in both my rigs (refer to my entry 07-26-15 for details) DEFINITELY do not sound soft; superb solid, well defined bass, no muddle and excellent differentiation ;wide open midband, excellent depth perspective, beautifully clear detailed trebles,excellent tracking and very dynamic and yes the midrange magic. The Koetsu Urushi is a superb cartridge when properly set up in a well designed med mass or higher mass arm mounted on an appropriate turntable interface.
Hi Lewm;HFN&RR July 2013 vol58 No07 Review of Koetsu Urushi Sky Blue. Evaluated by Ken Kessler in a SME Series 5 and compared with a Koetsu Blue Onyx & Gold Onyx. The compliance measured 13/13 vertical/lateral; mechanism very symmetrically balanced and ideally suited to medium/heavy tonearms. I have noted Maril555 entry where he uses a Graham Phantom Supreme 11 10" arm with a Urushi blue and he is very pleased with the performance of this combo on his turntable. The turntable/arm interface is very important. A review of the EAT E-Go 12" arm in HFN&RR April 2013, based on the current Phantom 11 Supreme has a measured effective mass of 13g both vertical/lateral; cartridge weight range 5-20g/ compliance range 8-20cu. Measurements by Paul Miller.
I have Koetsu Urushi Blue on Graham Phantom Supreme II 10" arm, and it is beautiful. Very quiet, tracks great and the sound is sublime. (it is on the new Hanss T-60 TT)
Hi Lewm Hi FI News and Record Review. I have owned a FR64s &FR64FX & FR66s many years ago. I used a KOETSU Rosewood in the FR64s many years ago and it certainly performed well in this arm.I would not consider the FR66s ideal for a KOETSU URUSHI or the stone bodied KOETSU's. The Triplanar is a superb tonearm but some users have reported variable results with KOETSU cartridges. As I have stated arm effective mass is only one aspect of compatibility. The Origin Live site has the specs of their arms and other info. Mass loading at the headshell if done carefully is an excellent way of fine tuning if needed. The Koetsu Urushi just loves the Goldmund T3b.Setting up of this arm my specialty. I collated info from Martin Colloms, David Wilson and info from a Goldmund Tech by phone many years ago re set up. The Koetsu also worked beautifully in the LUSTRE GTS801 Arm when properly set up.
Soundbuff, By all reports that I have ever read, the Urushi acts as if it does have a very low compliance in that it "likes" tonearms with high effective mass. For example, many have written in these forums that the Fidelity Research FR64S and especially the FR66S are "made in heaven" for the Koetsu cartridges. Can you quote your sources to the effect that the vertical compliance is higher than the manufacturer's published data? Also, can you say what is the effective mass of the T3b and the Original Live, respectively?
I own an Urushi and have only so far used it in a Triplanar, which is "medium mass" as tonearms go. I plan to try it in a FR64S soon.
Fellow enthusiasts;I have found that the Koetsu Black Urushi delivers superb performance in a Goldmund T3b on a Goldmund Studio( meticulously set up). Likewise another Koetsu Black Urushi performs superbly in a Origin Live Conqueror mk3c mounted on a MICHELL Orbe turntable, full plinth version. TF set at 1.92gr in my Goldmund arm/ TF set at 1.94gr in Conqueror arm; preamp CAT Legend. Please note that KOETSU quote a figure of 5 by10-6cm/dyne compliance, presumably a static measurement. Several reviews of Koetsu Urushi cartridges have indicated compliance figures much higher, both horizontal and vertical. You neither want a arm/cartridge resonance at the low frequency end of the audio spectrum either too low or too high, both situations are detrimental to high quality sound reproduction.Arm effective mass is only one factor in achieving compatibility with a particular phono cartridge, in achieving a desired result.
I have just ordered the Jade Platinum and when I receive it, will mount it on my Vector 3/ Basis 2500. I had posted a thread on this, and received a bit of helpfull advice. I went to relocate the thread to update it, but could not bring it up. I don't know if this helps, as the Jade is quite a bit heavier than the wood body Koetsu's. I have not heard any feedback from or since my thread that gave me any confidence that my Vector is a good match for the 13.1 gram Jade. It can't hurt to try it, so that is what I plan to do. I am considering the Phantom, and have heard the Dynavector arm may be a good match as well. As far as the wood bodies, I think the choice will be easier. The handfull of arms I would consider would be Basis Vector, Phantom, Triplanar Vii. Unfortunately, my job may prove a little more difficult.
I have owned the Koetsu Urushi & now a Jade. I have owned or own a SME V, a mass loaded SME V, Schroder SQ, Ikeda 407 and have tried a few other arms. IME, the Koetsu loves mass. This means a very high mass arm which lends to the Ikeda. The Bass gets much better & dynamics appear once the Koetsu is in a well controlled arm. Most people who find the Koetsu too soft have only used it in a medium or low mass arm. I don't agree with people who advocate some arms without having tried a high mass design. That is not what the Koetsu is about. Other cartridges might be a different story but not this one. Just use any arm you have & load it w. blue tak to hear the difference mass will make.
I have the Koetsu Urushi mounted on an SME IV.vi. Works for me. I don't have any experience with other high end arms but had always heard that SME & Koetsu was a nice match so I went with that.
I don't know of any one place that describes each of the Koetsu line. I have read reviews of single Koetsu cartridges in magazines over many years. Manufacturer's/distributors' literature typically praises every product in a way that obscures differences. A cursory Google search turned up the following review of three Koetsu's:
http://www.10audio.com/koetsu.htm
Of course, listening to them yourself would be best, but hard to do.
Is there anywhere that describes the characteristics of the various Koetsu cartridges James? You indicate lush for the Rosewood Signature - I saw the write-up on the Black (but that's not what I'd go for).
I'm also thinking Graham Phantom arm as a possiblity.
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