SME M2-9R vs Jelco TK-950S

[watchnerd]

I'm considering upgrading upgrading my tonearm. I'll be honest -- it's partly just because I want a new toy. A new tonearm would also let me transform my Gyro SE into a 2 arm setup (if I so choose, not sure it's a great idea).

I'm considering both the SME M2-9R:

https://sme.co.uk/audio/product/series-m2-9r/

And the Jelco TK-950S:

https://www.jelco-ichikawa.co.jp/cn3/tk-950s.html

Price is close enough between the two that I won't be deciding based upon cost.

Key Differences:

-- Effective mass of M2-9R is 4 grams less, making it a *slightly* better match (like 1 Hz better), for my MP-500 and some MCs I'm considering buying, if compliance numbers and calculators are to be believed.

-- M2-9R requires new arm board (~$180), but gain that sliding SME base dohickey. TK-950S should work with my existing arm board (mounting distance is the same as SA-750D, although overhang differs).

-- KEY: M2-9R uses gimbal bearings vs combo of static knife-edge + dynamic balance on the TK-950S. Pros and cons?

-- KEY: M2-9R adjusts VTF using counterweight + outrigger vs TK-950S uses static counterweight + knob to adjust dynamic balance spring. Pros and cons?

-- M2-9R includes VTA on the fly knob, TK-950S requires 3rd party accessory for VTA on the fly (which I already own)

-- Anti-skate: string (SME) vs dial (Jelco)

-- M2-9R doesn't allow direct DIN phono cable connection, while TK-950S does allow direct DIN connection

-- M2-9R max cart weight of 38 grams vs 35 grams for TK-950S. Which might matter if I ever get into SPUs?

-- M2-9R allows for any alignment you want (sliding base) vs TK-950S is Baerwald

-- British turntable + British arm vs British table + Japanese arm? (then again my carts are Japanese....)

-- M2-9R slightly prettier, IMHO

-- I have seen neither in person, nor heard either one of them

So based on all of this, which would you favor and why?

 

[Ceburaska]

I don’t have experience of either arm, but I’d recommend getting one with a detachable headshell if you want to use lots of different cartridges. That could also help you cut down to only one tonearm.

 

[watchnerd]

I don’t have experience of either arm, but I’d recommend getting one with a detachable headshell if you want to use lots of different cartridges. That could also help you cut down to only one tonearm.

They both have detachable headshells of the normal kind (not like the SME 309). This was indeed one of my criteria.

 

[watchnerd]

@Frank Dernie @DonH56

Can any of you mechanical engineering types comment on the pros and cons of knife edge bearings and static vs dynamic tonearms?

That's really the key technical factor at play here that I'm completely unsure about.

 

[Fitzcaraldo215]

Like almost everything about vinyl, including the “thrill, beauty, realism, dynamics, musicality, PRaT” or whatever, there is essentially no technical or solid comparative listening evidence to guide you. There are very limited specs without measurements to confirm them. So, you are completely on your own, as I was in my vinyl days, but always saying, what the F, can’t I get some better data about cartridge, tone arm or TT performance other than the illustrious MF’s or whoever’s warped subjectivity?

So, the whole fun of the vinyl game, if indeed there is any, is there are no easy answers. You just have to crap shoot and experiment, and often, as with cartridges, there is just heresay and tribal suport, but, alas, no return privilege. It is the good old days, like before persnickety audio science had anything useful to say. It is making audio great again, to paraphrase our fearless leader. The gurus, not science, will lead us.

Look, it is all just a euphonic circle jerk, so how can you possibly optimize it in sonic terms, anyway, except in your own feeble head? There are absolutely no more than a very few incomplete and imperfect technical answers. You just enjoy the tinkering and trial/error of your own “discoveries” and personal subjective “truths” or else you don’t, in which case you move on to digital and leave vinyl all behind. Wow! What a relief that is!

 

[watchnerd]

Like almost everything about vinyl, including the “thrill, beauty, realism, dynamics, musicality, PRaT” or whatever, there is essentially no technical or solid comparative listening evidence to guide you. There are very limited specs without measurements to confirm them. So, you are completely on your own, as I was in my vinyl days, but always saying, what the F, can’t I get some better data about cartridge, tone arm or TT performance other than the illustrious MF’s or whoever’s warped subjectivity?

So, the whole fun of the vinyl game, if indeed there is any, is there are no easy answers. You just have to crap shoot and experiment, and often, as with cartridges, there is just heresay and tribal suport, but, alas, no return privilege. It is the good old days, like before persnickety audio science had anything useful to say. It is making audio great again, to paraphrase our fearless leader. The gurus, not science, will lead us.

Look, it is all just a euphonic circle jerk, so how can you possibly optimize it in sonic terms, anyway, except in your own feeble head? There are absolutely no more than a very few incomplete and imperfect technical answers. You just enjoy the tinkering and trial/error of your own “discoveries” and personal subjective “truths” or else you don’t, in which case you move on to digital and leave vinyl all behind. Wow! What a relief that is!

Well, yes, tinkering is a big part of the fun.

But I also enjoy the educational aspect of learning about electro-mechanical engineering.

For example, right now I'm reading a very technical white paper about anti-skating.

I know very little about knife-edge bearings and dynamic balance tonearms, except that they fell out of favor for a while (SME once used knife edge, now they don't); I'm curious to learn about the trade-offs vs gimbal/static balance approaches.

 

[DonH56]

@Frank Dernie @DonH56

Can any of you mechanical engineering types comment on the pros and cons of knife edge bearings and static vs dynamic tonearms?

That's really the key technical factor at play here that I'm completely unsure about.

Sorry, I'm an electrical engineer, not competent to comment. My statics/dynamics courses were few and long ago. I could speculate but am betting someone else on ASR can do much better than that... All I recall is that knife-edge bearings had wear and stability problems, and the whole dynamic tonearm concept never seemed to really pan out in the real world (just wasn't effective). But those are maybe 30-year-old memories of articles, not any personal analysis, so could well be wrong.

 

[watchnerd]

Sorry, I'm an electrical engineer, not competent to comment. My statics/dynamics courses were few and long ago. I could speculate but am betting someone else on ASR can do much better than that... All I recall is that knife-edge bearings had wear and stability problems, and the whole dynamic tonearm concept never seemed to really pan out in the real world (just wasn't effective). But those are maybe 30-year-old memories of articles, not any personal analysis, so could well be wrong.

I had heard the same (for both), which is why I find it interesting that Jelco's new line uses knife edge bearings.. It may be that advances in material science have helped.

As for dynamic balance, I believe both Rega and upper-end SME arms still let you set VTF with a spring.

 

[Frank Dernie]

@Frank Dernie @DonH56

Can any of you mechanical engineering types comment on the pros and cons of knife edge bearings and static vs dynamic tonearms?

That's really the key technical factor at play here that I'm completely unsure about.

There is no problem with knife edge bearings. In order to get a problem there would need to be a local vibration level at the pivot greater than +1g which won't happen, despite what Linn said about high g levels when rubbishing knife edge bearings, the high g is at the stylus only, or at least if it occurs anywhere else there are big problems!
static v dynamic balance is moot unless records are very warped, and even then, the position of the pivot relative to the disc surface has a big influence too, I prefer dynamic on principle but all my arms are not...
FWIW I look for basic sound engineering in any record player, the correct place for the bearings permitting vertical movement is at the height of the surface of the disc. Their axis of rotation should be orientated normal to the cartridge. That gives the least azimuth and vtf variation with warps, it also means the anti-scate doesn't cause off-axis forces as well.
As far as stiffness is concerned, whilst it is more complex in all 6 degrees of freedom, a simple 1 DoF analysis will show that plinth vibration is directly coupled to the headshell at low frequencies, increases as the frequency rises to the arm resonance frequency, then goes down again and is close to zero once 2x resonant frequency is reached. This means that the more rigid and light the arm the higher up the frequency range plinth vibration will reach the part of the cartridge which should be stationary. Having written that though, something like the finger lift and headshell collar have an effect and they are at the cartridge body already...
One of the joys/frustrations with dicking about with record players is the fact they can be tuned to taste. I myself prefer a bit of the extra reverb one gets from not perfectly isolating the record player from acoustic and mechanical excitation.
The model of SME you are looking at certainly has the bearings in the "wrong" place (but so does the flavour of the month SAT at ludicrous price) I am not sure about the other one.

I have 4 record players, all sound different and I only have one connected now but I must say I hardly ever play a record these days.

 

[watchnerd]

There is no problem with knife edge bearings. In order to get a problem there would need to be a local vibration level at the pivot greater than +1g which won't happen, despite what Linn said about high g levels when rubbishing knife edge bearings, the high g is at the stylus only, or at least if it occurs anywhere else there are big problems!
static v dynamic balance is moot unless records are very warped, and even then, the position of the pivot relative to the disc surface has a big influence too, I prefer dynamic on principle but all my arms are not...

So all that noise about knife edge "bearing chatter" was just Linn FUD marketing?

They do seem to have gone out of favor for a while.

 

[Frank Dernie]

If the cartridge damping is high it "short circuits" the compliance at higher frequencies and the transducer performance is less good in the working range but it makes it more warp tolerant (ie the peak at the arm/cartridge resonance is lower) IMO this is a poor compromise except for a DJ. This would lead to more stylus movement shifting the (should be stationary) cartridge body and hence arm but this is just sh1t engineering for hifi.
The Linn stuff is actually pretty well engineered dynamically but their marketing BS verged on the dishonest IMO.

 

[Fitzcaraldo215]

The “perfect” bearing never existed. It is all in the specific implementation. And, as @Frank Dernie knowledgeably points out, there are so many other things in the arm’s design that can have a significant effect. Overthinking and over focusing on just the choice of bearings may be myopic. I think one needs to take a balanced (pun, pun!) view of the whole thing.

They all work, they all do their jobs and play music. Which very subtle shadings, if any, of sonic difference would you like? And, that is probably minor relative to the cartridges’s much more significant sonic contribution in any case. Although, as we know, matching arm mass with cartridge mass and compliance as best you can is crucial.

Having said all that, I never liked and would never have considered a unipivot arm, myself. Nice theory, but too awkwardly unbalanced in use for me. It is probably just an emotional bias on my part. But, emotional bias, looks, prestige and maybe a few adjustment features probably are the keys to most all tonearm purchases. I don’t recall ever seeing a tonearm that was not carefully and well engineered, albeit to different design philosophies, possibly some with designer technical blind spots built in.

 

[watchnerd]

If the cartridge damping is high it "short circuits" the compliance at higher frequencies and the transducer performance is less good in the working range but it makes it more warp tolerant (ie the peak at the arm/cartridge resonance is lower) IMO this is a poor compromise except for a DJ. This would lead to more stylus movement shifting the (should be stationary) cartridge body and hence arm but this is just sh1t engineering for hifi.
The Linn stuff is actually pretty well engineered dynamically but their marketing BS verged on the dishonest IMO.

The “perfect” bearing never existed. It is all in the specific implementation. And, as @Frank Dernie knowledgeably points out, there are so many other things in the arm’s design that can have a significant effect. Overthinking and over focusing on just the choice of bearings may be myopic. I think one needs to take a balanced (pun, pun!) view of the whole thing.

They all work, they all do their jobs and play music. Which very subtle shadings, if any, of sonic difference would you like? And, that is probably minor relative to the cartridges’s much more significant sonic contribution in any case. Although, as we know, matching arm mass with cartridge mass and compliance as best you can is crucial.

Having said all that, I never liked and would never have considered a unipivot arm, myself. Nice theory, but too awkwardly unbalanced in use for me. It is probably just an emotional bias on my part. But, emotional bias, looks, prestige and maybe a few adjustment features probably are the keys to most all tonearm purchases. I don’t recall ever seeing a tonearm that was not carefully and well engineered, albeit to different design philosophies, possibly some with designer technical blind spots built in.

Thank you for the detailed replies.

So here is the challenge I'm finding myself facing:

Even in my metro area, brick and mortar hi fi stores are thin, and those few that exist carry little to nothing in the way of turntable stuff. And what they do carry, tends to be all-in-one integrated turntable solutions (a la Clearaudio), as opposed to stand alone tonearms. As a case in point, the nearest SME dealer to me is in Portland, Oregon, a good half a day's drive / short flight away.

Thus, my ability to actually take my cartridges someplace and listen to them on various tonearms is practically non-existent.

On the flip side, there are plenty of online places to buy tonearms. But I can't hear them.

So this leaves me with trying to suss things out via measurements, effective mass / cartridge resonance calculations (I have a whole Excel spreadsheet full of these calcs), and some deductive reasoning.

And, sadly, measurements of tonearms are extremely rare.

And what does a good tonearm measurement look like? Is it all about resonance decays?

Which seems to leave me with just buying based on reputation for quality, looks, and features....

 

[Fitzcaraldo215]

Among the many issues with vinyl, this lack of detailed measurement and lack of adequate ability to do my own prepurchase listening audition were killers for me. There was just not ever enough good, reliable technical information available on the components involved in LP playback, except maybe phono preamps. It is actually even worse today in many ways than back then when vinyl was king. We are in the dark, but we have our wonderful gurus like MF, AD, etc. and their impeccable ears or dealers or buddies telling us all we need to know. Yeah, right.

Many love that totally subjective ballgame, like WBF. But, that is essentially all there is for vinyl. There are no objective standards for higher fidelity, transparency, lower distortion, etc. for consumers like us. Designers and manufacturers undoubtedly know much more technically than they tell us. But, for us, it is only what is more pleasing subjectively in a lot of trial and error using LPs in the Circle of Confusion where we don’t really know exactly what sound is cut on that particular pressing of that LP however worn by playing it may be. Compound that with all the permutations and combinations of cartridges, arms, TTs, preamps, and have fun trying to optimize all that for highest fidelity.

So, the whole mindset about component selection and system optimization is totally different for vinyl. It is a light year away from the mindset with digital. Just enjoy the music and go with your gut. You just have to get used to that and forget all about measurements and concepts of higher fidelity elsewhere in this forum.

Some say that is all fun and sounds great. Not for me, though.

 

[watchnerd]

Among the many issues with vinyl, this lack of detailed measurement and lack of adequate ability to do my own prepurchase listening audition were killers for me. There was just not ever enough good, reliable technical information available on the components involved in LP playback, except maybe phono preamps. It is actually even worse today in many ways than back then when vinyl was king. We are in the dark, but we have our wonderful gurus like MF, AD, etc. and their impeccable ears or dealers or buddies telling us all we need to know. Yeah, right.

Many love that totally subjective ballgame, like WBF. But, that is essentially all there is for vinyl. There are no objective standards for higher fidelity, transparency, lower distortion, etc. for consumers like us. Designers and manufacturers undoubtedly know much more technically than they tell us. But, for us, it is only what is more pleasing subjectively in a lot of trial and error using LPs in the Circle of Confusion where we don’t really know exactly what sound is cut on that particular pressing of that LP however worn by playing it may be. Compound that with all the permutations and combinations of cartridges, arms, TTs, preamps, and have fun trying to optimize all that for highest fidelity.

So, the whole mindset about component selection and system optimization is totally different for vinyl. It is a light year away from the mindset with digital. Just enjoy the music and go with your gut. You just have to get used to that and forget all about measurements and concepts of higher fidelity elsewhere in this forum.

Some say that is all fun and sounds great. Not for me, though.

Ugh....

What you say makes sense.

And, I don't even try to drive LP to a standard of higher fidelity for obvious reasons.

But I find it very very hard to intellectually and emotionally just go with my gut, especially when there are actual variables in LP to be considered (e.g. compliance matching to mass, MC loading) that really do make a difference in a measurable way.

 

[Fitzcaraldo215]

Ugh....

What you say makes sense.

And, I don't even try to drive LP to a standard of higher fidelity for obvious reasons.

But I find it very very hard to intellectually and emotionally just go with my gut, especially when there are actual variables in LP to be considered (e.g. compliance matching to mass, MC loading) that really do make a difference in a measurable way.

Agreed, there are some important, objective measures that can help with vinyl like those you mentioned. Not too many for tonearms, though. Compliance to effective mass is very important with sonic effects. I can remember reading long math treatises on Baerwald arms vs. arms with other tracing geometries years ago, but that’s old hat now and seemed insignificant even then. Some obsess on VTA even adjusting for each LP, anti-skating, etc. Alignment tools are also much better today, including electronically for cartridge azimuth.

Fremer, for all his sins, is actually quite thorough and anal about all this mechanical setup stuff. Maybe he has a book or guide somewhere that would be useful. If he does, it would be good and definitive, I am sure. I would use it myself, if I still did vinyl. I still read his column in Sphile, though I cringe often at his ego-centric subjectivity in listening.

He even records different tonearms with the same cartridge and TT, doing it digitally at 96k, of course. He plays those at his seminars at shows for all to hear the differences. I don’t know that he has ever provided a clear, coherent answer to the paradox of why digital is so much worse than vinyl if digital can capture the tiny sonic differences between tonearms.

But, even with the most obsessive, ideal tonearm setup on the same TT with the same cartridge, are there any worthwhile sonic differences between arms given vinyl’s propensity to higher distortion, dynamic and channel separation limits, susceptibility to warps and eccentricities, etc.?

Who knows for sure? But, have fun finding out. To me, it all starts to approach the Heisenberg uncertainty principle, except applied to audio. So, you gotta go with your gut. There is no definitive proof.

 

[JJB70]

Many years ago I found there were in general two attitudes to vinyl. Some people loved all of the tinkering and mystique around vinyl and were borderline obsessed with arcane details associated with tone arms, cartridges etc. Others just wanted to enjoy music and were as happy as could be at being able to leave all of that behind. There seemed to be little middle ground, I was in the latter camp.

 

[watchnerd]

Agreed, there are some important, objective measures that can help with vinyl like those you mentioned. Not too many for tonearms, though. Compliance to effective mass is very important with sonic effects. I can remember reading long math treatises on Baerwald arms vs. arms with other tracing geometries years ago, but that’s old hat now and seemed insignificant even then. Some obsess on VTA even adjusting for each LP, anti-skating, etc. Alignment tools are also much better today, including electronically for cartridge azimuth.

I've actually read those alignment articles.

And spent $100 on an alignment jig with mirror surface and null points specific to my TT + arm combo.

And then when it finally come to peering through a loupe and trying to move things fractions of a millimeter, and realized alignment differences were in the range of 0.5% distortion, I threw up my hands and said "f*** this....good enough."

I also don't recall anybody every talking about getting their turntable aligned in my childhood....which makes me wonder if it was a lot of to do over not much.

And now I'm reading about anti-skating....which is an even more difficult conundrum, as there is not only lack of an agreement about what the best compromise should be, but also no ready to use tool to measure the variable skating force (and thus how much to offset it, on average).

But, even with the most obsessive, ideal tonearm setup on the same TT with the same cartridge, are there any worthwhile sonic differences between arms given vinyl’s propensity to higher distortion, dynamic and channel separation limits, susceptibility to warps and eccentricities, etc.? .

This is what I find so mind boggling and fustrating:

Many subjective reviewers claim that large "night and day" differences between tonearms. I've seen claims that 25% of a TT system budget should go to the tonearm.

However, how many of those differences are just manifestations of changes in effective mass?

I would say I think (I've never blind tested myself...blind LP tests are hard to do*) I can tell a difference between no fluid damping and the manufacturer-specified fluid damping for my Jelco SA-750D, which I don't think is beyond rationality.

*I could make a digital rip and submit myself and others to AB testing it, I suppose.

 

[watchnerd]

Many years ago I found there were in general two attitudes to vinyl. Some people loved all of the tinkering and mystique around vinyl and were borderline obsessed with arcane details associated with tone arms, cartridges etc. Others just wanted to enjoy music and were as happy as could be at being able to leave all of that behind. There seemed to be little middle ground, I was in the latter camp.

I may be moving to the later camp, as I'm starting to feel like complex stylus shapes (line contact, Shibata, micro ridge, microline, Fitz Gyger, Replicant, etc etc), while definitely higher fidelity, may not be worth all the fussing about. I'm not an analog supremacist, so if I want higher resolution, I'll just listen to digital.

My recent purchase of a conical mono cartridge has been an educational journey on the value of a cruder, simpler set up that let's me just get on with record listening.

This has caused me to think about moving to an unfussy elliptical stylus for stereo and just call it a day.

 

[DonH56]

I moved to unfussy CDs many years ago and called it a decade. Or two...

The ability to tweak to the nth degree is a blessing and a curse but after the initial fun unless you're retired and/or happy with listening to an album in an evening it gets old quick. Maybe just me...