Lewm, its an old SME V arm issue due to the conical, increasing arm thickness toward the gimbel bearing, when a cartridge is about 16mm stylus tip to mounting platform (more usual is 18mm or yet more like e.g. Ortofon Quintet) the arm (9") starts to faul on the outer edge of the record. Lifting the stylus out of the inner groves as a result.
I hope this describes the problem, this made even worse when the record is only a little warped?
It also happens that a marginally longer mounting screw projecting beyond the nut when the screw head is used at the top, with e.g. Shure V15-III phono cartridge fauling the same way, as the Sure is also about 16mm or even less with the SAS replacement stylus 😟
Michélle
|
I'm just curious, what exactly is this SME V spacer made of. Metal (Magnesium...) or some Duroplast hard plastic and its weight?
Having had a similar issue as you (OP) mentioned, with my Ortofon M20FL Super cartridge, I, at the time managed to make a spacer from Beach hardwood 3mm thick, and it still serves me fine.
The weight is about 0.65 gramm, and the cartridge with only 5 gramm being on the light side, it seems just fine. |
One more thing, this fauling happens when the arm is set LEVEL and correct tracking force is applied.
|
Hi Jim, I'd be still interested if you could mention the spacers weight, if you'd have e.g. a VTF scale/gauge.
I my case, a 0.66 gram addition to 5 gram cartridge weight is not to my ears changing the sound negatively on the SME V's 10.5 gram arm mass at all.
Rather helpful it is in this case, as the balance weight is a little less cramped right up to the front, toward the arm bearings.
Depending on the cartridge's compliancy (cu) it might even be better (or not?) regards the change of the resonance frequency.
Some would say its immaterial depending on your tt set-up and placement, regards foot fall or seriouly warped vinyl etc.
This just to have mentioned, to calm down some audio-nervosa cases' comments. 😉
Michelle
|
@chakster many thanks for your kind offer.
I had years back partaken of @raoul's endless MM thread vs the rest of the worlds MC cartridges, where this item was also for a brief moment the top cart of the day (or week?).
Yes, a nice cart, if in need of a spacer when using it on an SME V, IV, etc. conically formed tonearm.
At present I've settled to use my Ortofon Cadenza Black, once I learned to use the arm's damping, rather than to ignore it, and so now find it to be a slight improvement on the 20FL.
It is now a backup plus a 40 cu 20E stylus... acquired at the time, under the spell of Raoul's finding it superior to the FL! (I do know your position on elyptical styli, ha)
But those were the days in 2009 ☺
Therefore, no present need for yet a further backup.
Thanks again, Michelle 😉
|
@chakster you are absolutly right, but... what did I know in 2009 🤔 🙄 😏
Funny however, despite this extemely high 20E compliancy (40cu), plus elliptic vs 20FL fine line, it works and sounds pretty much the same... maybe a tad less grainy at times compared to the 20FL stylus?
I mention this as, in my listening, it relativates a lot that is said about all this arm weight vs compliany vs resonance (also changed by spacers).
All seems not QUITE as critical as often mentioned.
Also note the 20E's recommended VTF is 1.1 gram and 20FL's VTF is 1.4 gram.
In any case MM/IM/MI expert Raoul prefered the 20E at the time as mentioned.
What arm did he use? Medium, Light,... it was not a subject of the discussion at the time, as I recall. 🥴
Maybe @lewm has a better memory?
So much for spacers, arm weight, cu, etc. and influencing the sound, eh? 😉
Michélle
|
Hi Jim,
There exists an old Excel file that I had down loaded using a formula doing what you are looking for.
Maybe one of the longer standing experts like e.g.@lewm knows about it and be able to direct you to the original sourse?
Mine has been modified to a more current version of Excel and a number of my own cartridges added to it in addition to the original content.
Presently I'm not clued up how to create a link to mine in Agon, I'd know however to send it as an email attachment though.
As an alternative, let me know the Kiseki's weight plus mounting hardware, I'll then add the 3gram spacer enter it into my Excel file and can post back the calculated resonance frequency.
Just as a work-around suggestion?
Michélle |
Sorry, I also would need the cu (compliance unit) of course, the arm mass for the SME V I'd use as 10.5 gram.
However, if you use the silicone damping tray function (some more or less) it can be argued that it would effect the arm mass slightly too. By this shifting the arm mass toward the quoted upper range of 10—11 gram e.g. 11 gram, this if the pin is screwed down to the second marking for example.
In other words pretty much fully immersed in the silicone.
This is all very finicky and in final analysis it'd STILL depend on your listening impression what you prefer of course.
In my experience, a low cartridge weight ~ 6 gram and high/soft compliance > 20 cu, asking for a light mass arm, I would use no damping at all, lifting the screw pin up past the first marking (tray filled to the correct level with the correct viscosity silicone gue).
On the other hand, with a cu of about 15-16 (medium stiff) and a cartridge mass of ~9 grams I find a medium immersion somewhere between the two markings suitable, and as the cartridge mass goes up to e.g. 13 grams (still at 15-16 cu) the damping again can be reduced toward no damping, since the increased cartridge mass is adding more inertia (this is my rational).
A low cu of 10 and less, with a low cartridge mass, e.g. a 103 Dennon with plastic body, would then again require a higher damping setting, assuming my rational makes any sense 😉
Yet, trust your ears!
Michélle
|
Ok, actually did find the Purple Heart specs on line:
Weight: 7 g (jolly light for its size methinks)
Compliance : 16cu
Arm mass used: 10.5 g
Therefore resonance frequency: 8,7793 Hz
This being well within 7 - 12 Hz range.
As for the damping, I'd suggest pretty much in the middle between the two ring markings and more towards the bottom ring mark (lighter damping).
This when I compare it to my Ortofon Quintet Black, with Shibata stylus, 10.8 g mass incl. cart leads, brass mounting screws, and cu 15. Resulting in rf of 8.9 Hz.
Michélle
|
The rf without the spacer by using the 7 gram cart mass only, is showing up as 9.5 Hz.
Still well within the accepted range of 7-12 Hz.
Though in this case I'm not quite sure about the best damping setting with the SME V arm.
My intuition tells me the set-up with the spacer, considering the cu of 16, will be more favourable.
If the cu was more toward 18-20 then I'd opt for the setting without spacer, but not with the SME V arm, due to the issues mentioned.
So all this looks IMO (and YMMV), just fine using the spacer with this cartridge, on the SME V arm.
Finally, DO NOT underestimate the finer differences in SQ that small changes in damping settings will do.
Michélle |
