SME 3009 Bronze Knife Bearing modification, cautionary tale

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addicted2tt
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SME 3009 Bronze Knife Bearing modification, cautionary tale

Post by addicted2tt » 07 Apr 2010 11:03

Hi,

Replaced the Nylon knife bearing on my 3009 SII Imp (det. headsh.) with a Bronze one.
Having read the favourable review by Hartmut Quaschik at TNT (Bronze bearing on SME 3009RM), I was probably expecting the same good result on my 3009 II/Imp/det.hs.
This was not to be however: On the positive side, there were improvements in terms of clarity, attack, and tonal colour, all contributing to the arm sounding more "alive", but at the same time violin and cello for example got overly "metallic" (definitely bordering on being aggressive), and the bass foundation shrunk together to such an extent that it could be called a total collapse - what was left only hinted at what once had been there, with the Nylon bearing in place. Tried to see if tightening the 2 knife bearing holding bolts to various degrees would have any impact, and it did - but the overall quality was still as described above, i.e. borderline aggressive at times with no bass to speak of.
In comparison; with the Nylon knife bearing in place, this arm sounds more laid back - but absolutely not uninteresting, and above all; it sounds fairly evenly balanced top-to-bottom - very musical, and a joy to listen to.
If you are an SME 3009 II/Imp. owner, this might be something to consider before getting one of these Bronze bearings. For instance, one manufacturer of them, AKA (Analog Tube Audio), doesn't seem to say anything other than that: "The Analog Tube Audio bronze knife edge bearing offers an excellent and outstanding upgrade for the SME 3009, 3010 and 3012 tonearms." and that: "...the bronze knife edge bearing doesn’t fit on the SME 3009-3, because the construction of this tonearm is different to classical 3009 tonearm". At the same time Mr. Quaschik/TNT concluded that the bronze bearing did not improve his 3012 arm, but actually made it sound worse: "While the Bronze bearing enhanced fine detail resolution and bettered the sibilants compared to the old steel knife edge bearing, bass depth and soundstage got smaller, and what is worse, the tonearm lost its charme, or in other words, its singing quality. "
Mr. Quaschik/TNT again: "To summarize: the modification is recommeded for the series R tonearms, but objected for the old series 2 tonearms." I haven't been able to find any mention of this recommendation on Analog Tube Audio's website . Please note; quoted as spelled in the review at TNT.
Anybody else tried this modification on the 3009 II/Imp?

LousyTourist
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Post by LousyTourist » 07 Apr 2010 13:24

hopefully you can undo the change and put it back to right.

I am in a minority, I know, but I tend to think (especially for a heavily engineered bit like an SME tonearm) that aftermarket stuff definitely changes the sound, but whether it improves the sound is debatable. I think I remember reading an article where the SME engineers decided on nylon due to more or less the same reasons you listed.

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Post by Sir Bakerman » 07 Apr 2010 13:39

Very timely post. I was really considering this upgrade along with the FD-200 assembly (If I can get one). Now perhaps I will wait and just concentrate on a better cart. One thing for sure the arm is really quite wonderful comparatively speaking to what I had previously.

I will continue to view this post for further debate.

Thanks for your opinion.

Sir B

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Re: SME 3009 Bronze Knife Bearing modification, cautionary t

Post by audioorigami » 07 Apr 2010 18:15

addicted2tt wrote:Hi,

Replaced the Nylon knife bearing on my 3009 SII Imp (det. headsh.) with a Bronze one.
Having read the favourable review by Hartmut Quaschik at TNT (Bronze bearing on SME 3009RM), I was probably expecting the same good result on my 3009 II/Imp/det.hs.
This was not to be however: On the positive side, there were improvements in terms of clarity, attack, and tonal colour, all contributing to the arm sounding more "alive", but at the same time violin and cello for example got overly "metallic" (definitely bordering on being aggressive), and the bass foundation shrunk together to such an extent that it could be called a total collapse - what was left only hinted at what once had been there, with the Nylon bearing in place. Tried to see if tightening the 2 knife bearing holding bolts to various degrees would have any impact, and it did - but the overall quality was still as described above, i.e. borderline aggressive at times with no bass to speak of.
In comparison; with the Nylon knife bearing in place, this arm sounds more laid back - but absolutely not uninteresting, and above all; it sounds fairly evenly balanced top-to-bottom - very musical, and a joy to listen to.
If you are an SME 3009 II/Imp. owner, this might be something to consider before getting one of these Bronze bearings. For instance, one manufacturer of them, AKA (Analog Tube Audio), doesn't seem to say anything other than that: "The Analog Tube Audio bronze knife edge bearing offers an excellent and outstanding upgrade for the SME 3009, 3010 and 3012 tonearms." and that: "...the bronze knife edge bearing doesn’t fit on the SME 3009-3, because the construction of this tonearm is different to classical 3009 tonearm". At the same time Mr. Quaschik/TNT concluded that the bronze bearing did not improve his 3012 arm, but actually made it sound worse: "While the Bronze bearing enhanced fine detail resolution and bettered the sibilants compared to the old steel knife edge bearing, bass depth and soundstage got smaller, and what is worse, the tonearm lost its charme, or in other words, its singing quality. "
Mr. Quaschik/TNT again: "To summarize: the modification is recommeded for the series R tonearms, but objected for the old series 2 tonearms." I haven't been able to find any mention of this recommendation on Analog Tube Audio's website . Please note; quoted as spelled in the review at TNT.
Anybody else tried this modification on the 3009 II/Imp?
the lighter newer 3009 arms may not be as suitable for the brass bearings as the older heavy armtube sme arms

so some of your points are very valid
but there is also the issue that you may have upset the horizontal bearing in some small way...and or damaged the headshell conector when soldering it

would be great if you revers the job and see if its still the same old arm your remmebr

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Post by addicted2tt » 07 Apr 2010 20:36

I never de-soldered the connector - the knife bearing can be replaced without having to do that, if some care is taken fixating the armtube just above and out of contact with the bearing-yoke which is what I did, so all soldering joints are original/untouched.

I have now put the Nylon knife bearing back, and (THANKS...there is someone up there watching over me...), the sound quality has been restored to its former self :D
So, I for one do not recommend this modification to anybody owning this version of the 3009 tonearm. Mr. Hartmut Quaschik/TNT seem to be of the opinion that this incompatibility issue might have something to do with the aluminium armtube in the older versions of the 3009/II and in the 3012 (= bronze bearing makes these arms sound worse), and the steel tube used in the later 3009RM/3010RM (and the "R" in which the bronze bearing = improvement).
I can only write about my own experiences, but it would seem to make some sense, that the very different metals involved would have a fundamentally different "sound signature" when coupled together as in the case of the SME saddle style knife edge bearing (various physical properties, resonance interaction and energy dissipating patterns..???).

:?
It would be interesting to hear if someone else has done this with an aluminium tubed SME, and to learn about the result.

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Re: SME 3009 Bronze Knife Bearing modification, cautionary t

Post by addicted2tt » 07 Apr 2010 22:52

audioorigami wrote: the lighter newer 3009 arms may not be as suitable for the brass bearings as the older heavy armtube sme arms

so some of your points are very valid
Hello audioorigami,
It's my understanding that the first (earliest) 3009 and 3012 arms (i.e. "Series I") had steel armtubes, whereas the Series II had aluminium ones. The "Series I" arms were only produced during the first couple of years (1959-1962). Then, in 1963, came the Series II arms. The "Improved" models of the 3009 (with fixed or detachable headshell) came in the early 1970's and the later (1980's) "R" series had steel tubes again, possibly trying to emulate some of the sound qualities found in the Series I arms and better suit lower compliance cartridges.
It was on one of these late (1980's) 3009RM steel tubed arms, that Mr. Quaschik at TNT favourably tried out the bronze knife edge bearing.
I can see no reason per se, why a bronze knife edge bearing assembly shouldn't work well on an aluminium armtube - I feel it's just something that must be determined by
trying it out.

What I somewhat object to, is that these bearings are being offered from a number of vendors as a quick fix "improvement" for all 30xx arms (bar the Series III).
As for the "validity" of my points (and I mean all of them...he he) - they are mine and based on my listening alone - I'm not presenting them as anything else - and as such I feel they are all "valid".
:)

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Post by audioorigami » 07 Apr 2010 23:13

yes you are correct

but its not just the arm tube material or thickness that is the whole story....in the early sme arms they used a thick almost silcone type substance inernally in the arm tube and on some of the later units they used balsa wood damping inside the arm tube...and from memory most of these units would have the black metal bearing

the units with the plastic bearings all seem to have thin walled alloy tube and no damping in the arm tube at all

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Post by john guest » 07 Apr 2010 23:47

Hi ,

I have put a brass Knife bearing on my 3009 S2 improved aluminum arm shell at the same time as I re wired . My arm was dampened inside with some form of cloth fibrous /white material . at the time comparing the two bearings , I immediately notice a tightening of the base and of the highs. It also had, although I would not think it would , had a big impact on the arm mass . At the same time I also moved to a heavy head shell which improved the base no-end . The effect on my turntable arm combination was totally the opposite to addicted2tt , but in saying that , I had change the headshell rewired and replaced the balance weight for the heavy 168 Gram one from SME . The Sumiko heavy head shell definitely was the biggest improvement in tightening the base up.
Best Regards,
John Guest

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Post by addicted2tt » 07 Apr 2010 23:49

Hello audioorigami,

I agree that the damping materials (or lack thereof) have varied, even though the most common find is the balsa wood stick.
I always thought that the later "R" series had stainless steel tubes.

The point made earlier by LousyTourist is an important one: "I think I remember reading an article where the SME engineers decided on nylon due to more or less the same reasons you listed."

It's easy to perceive this piece of plastic as being quite out of place when it sits as an integral part of what is essentially a very substantial and complex, beautifully made precision engineered piece of kit as the SME arm...so there must be some sort of justification for it, and having now heard the very nicely finished and well fitting precision engineered bronze knife edge bearing in play, I can see wherein this justification lies. Anybody out there still believing that the nylon bearing is purely a production cost saver better think again. This is purely speculative, but maybe this "belief" to some extent helps selling these bronze bearings ("...surely they must be better...than this...").
Having said that; I'm not in any way disputing that Mr. Quaschik at TNT found a substantial improvement when he reviewed the bronze bearing on his 3009RM (steel arm tube), and I'd be very interested in listening to that arm playing. Mr. Quaschik also expressed being perplexed over the lack of improvement when the bronze bearing was fitted to his SME 3012 arm (aluminium arm tube), and instead described how his nice sounding 3012 just fell to pieces sound wise; no bass etc. with the bronze item in place...
:D

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Post by starterwiz » 08 Apr 2010 04:02

I have not played with the bearing on my 3009 yet, so the following is purely speculation.

The bearing surfaces would need to be very well mated to perform properly. Think of a good fineline tip making contact with a groove wall. The angle of the edge of the tip needs to be spread over a long vertical surface or it becomes a sharp point of contact digging into the vinyl.
A new brass bearing would need to have it's profile matched to the lower bearing surface. Perhaps using a method similar to that used by guitar builders matching the profile of a neck heel to the body of the guitar.
The two sufaces are brought together with a piece of fine sandpaper between them. When the sandpaper is drawn out, the surfaces that are in the closest contact are evened out perfectly. A gentle re-sharpening of the bearing after this procedure should result in a perfectly mated pair of surfaces.
The increased friction of a larger contact surface would stop the motion at the bearing that is causing the loss of bass.

I would think that an old nylon bearing would have seated itself properly over time, and the new brass one needs some dressing.

Just a thought.

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Post by addicted2tt » 08 Apr 2010 11:59

Yup definitely a good point, but at the same time the review at TNT didn't mention any special mating period or -procedure; the impression given in that review was that the bronze bearing simply improved the 3009RM quite substantially straight away, whereas the opposite was true when it was placed in the 3012...go figure :?

The TNT review can be found here:

http://www.tnt-audio.com/accessories/smebronze_e.html

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Post by starterwiz » 08 Apr 2010 23:07

I sell and install car audio. Usually the install is more important than the components used. I see no reason why it would be any different with a vinyl set-up.
The best tweaks in the world will suck if not installed properly.

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Post by john guest » 08 Apr 2010 23:08

Hi ,
Just for information, I Email SME technical now and then when I purchase parts from them . I thought it would be useful for this post to send them the following Email, which I did yesterday.
to:-SME Technical

I wonder if you could be so kind to ask one of your Technical engineers why the plastic Knife edge bearing was used instead of the metal bearing as in the earlier 3009 arms .Know one seems to have the answer or the reasoning behind this change .

Best Regards,
John Guest.
I have received the reply today below :-
Subject :-plastic bearing on 3009 s2 improved arm

Hello,

Thank you for your recent email.

The plastic knife edge was introduced following extensive tests which found an improved performance to the earlier metal bearing which could in some circumstances become resonant, a feature not experienced in the plastic version.

Regards
SME Limited

SME made the improved arm as light as possible for the MM cartridges of the day , It may be because of this the resonate nodes did have an effect on the Metal bearing and that's why extensive tests proved the plastic bearing to be better.

I have made my SME arm heavy with the change in Weight 168grams ,and change in head shell I find the brass bearing to improve the sound in my system.

However , Any user of the standard arm (ie standard arm mass ) I think should stay with the findings of SME. I think this gives good reasons and coincides with the findings of addicted2tt findings.

Best Regards,
John Guest.

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Post by addicted2tt » 09 Apr 2010 01:06

Hi John Guest

Good effort e-mailing SME directly :D

Yes, their reply is very enlightening.

I'm right now listening to and fully enjoying the 3009 Imp./Nylon bearing, and I'm very pleased that the this modification was fully reversible.

I think that what you say about your weighed down version of the 3009 SII arm working well with the bronze bearing makes a lot of sense too, since I feel it might very well behave completely different as regards resonances etc...more along the lines of the already much heavier 3009R version - this too is very useful information, since I have another 3009/II that I might want to use with a lower compliance MC cartridge in the future - I will make sure to try your recipe - thanks!

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Post by Alec124c41 » 09 Apr 2010 08:18

I got an SME 3009 series 2 improved arm with detachable headshell, on a Technics SP-10.
My initial impression was god, but it seemed to miss the fine articulation of the sound that I like.
I replaced the nylon bearing with a bronze or brass one. Yhe detail was there, but also something a bit excessive. Resonance in the armtube seemed a logical suspect, so I put a piece of black Dynamat, about 2 mm wide by 20 mm long, on the bottom of the armtube, just forward of the lift dash-pot. This worked a bit too well, so I cut it back to 10 mm length, and this sounds just about right. I like it. I think t is an improvement over the nylon bearing. YMMV.

Cheers,
Alec

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