SME 20/12 and 312S Tonearm Reviewed

Published On: January 4, 2009
Last Updated on: March 9, 2022
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SME 20/12 and 312S Tonearm Reviewed

This combo was designed specifically to handle 12-inch tonearms. Using a special diecast magnesium material, the new SME tonearm is both rigid and lightweight. In the past no materials existed that offered this combination of physical attributes but magnesium makes longer tonearms possible

SME 20/12 and 312S Tonearm Reviewed

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Clarity is the quality that most exemplifies SME's Alastair Robertson-Aikman, and on many levels. It's a property of the sound reproduction of his company's products, of the very instructions contained in SME owner's manuals, and - above all - it applies to Alastair's thinking. Had he ever decided to embrace the dark side, by going into politics or law, we would be living in a very different country, indeed. It's this clarity, in all of its forms, that is embodied on not one but two new products from SME, a company that is positively Quad-like in the rate at which it introduces new models.

And they are never introduced 'just for the sake of it.' Invariably, a new model arrives because AR-A had a brainstorm while tweaking his system, a vision that results in some canny device which his éclaircissement will render so obvious that you can only marvel at the ingenuity. This time, the two products are so closely interrelated that the words 'chicken' and 'egg' might spring to mind. But, in fact, the first to arrive was the 312S tonearm.

Additional Resources

SME has had 12in tonearms in its catalogue for over 40 years, but they've always had appeal mainly on cult level. As AR-A explained, 'In the past, there have been many 12-inch tonearms used especially in record manufacture. They lost popularity because their extra length meant that they were either too heavy or not stiff enough, and it is only with the advent of our magnesium tonearm that these problems were addressed.'

Alastair thus had an impetus for pursuing once again the benefits of 12in arms, in the form of ultra-light, ultra-strong magnesium; you can stand on a 9 in SME pressure die-cast magnesium tone arm tube and it will not bend nor break. The benefits of a mere three inches? Primarily the reduction in tracking error that occurs because the arc that the cartridge follows in a 12in arm is closer than the arc of a 9in arm to the ideal straight line of the LP cutting head. It's geometry so simple that even I can understand it. And if you want numbers, Reg at SME calculates that a 12in arm is 27.23 percent better than a 9in arm for both angular error AND distortion.

So, while some of us have happily employed the 12in Ortofon, the SME 3012, M2-12 or even the regular 312, or other 12in arms, we have had to deal with a trade-off: substantially reducing the distortion due to the tracking error of a 9in arm [see chart], while having to deal with the inevitable increase in the effective mass of the longer arm. The arrival of the 312S, however with its arm tube made entirely of magnesium, enables the increase to be sufficiently off set and no longer an issue.

AR-A notes that, 'The tonearm fitted to the 312S, including the headshell, weighs 48g. This compares with 75g if it were made in aluminium, making it unsuitable for cartridges of normal compliance, that is, between 20 and 25cu.' So now we have a 12in arm, probably the lowest mass 12in tonearm ever made, that is quite comfortable with the vast majority of cartridges in the 'normal' weight range of circa 6g-12g.

Other benefits that are provided by the 312S include a smaller excursion of the counterweight, higher contact loading of the bearings, all must have some clearance! greater length in which the acoustic signal generated in the arm can dissipate, a reduction in susceptibility to warp/wow, and a greater range of movement when adjusting VTA. So it's not just the reduction in tracking error that make 12in arms so appealing, once they're free of concerns about effective mass.

SME merged elements of the Series V, including its arm tube and damper, with the counterweight assembly and detachable headshell of the Series 300 to create the 312S. Increasing the Series V's arm to 12in status involved fitting an extension to the basic Series V tube, using pressure fitting and an adhesive, the arm then finished entirely in black.

Which begged the question that led to a second new model: To what can it be fitted? The SME 10 was out, because under no circumstances would AR-A countenance an arm-board extension floating out in the breeze. (Of course, any extension SME would fashion would be as robust as one could possibly want, but Alastair does not approve of arm-boards supported only at one point.) And the SME 30/2? Because it was conceived as a cohesive source component with the Series V, and because its performance is so far 'out there' as to obviate any need for improvement, that combination was left alone. For the time being, at least.

SME had introduced new power supplies for the entire range in late 2005*, so the turntables were all 'up to date.' There was, however, a substantial price difference between the SME 20/2 and SME 30/2. Adapting the former to cope with a 12in arm presented a perfect opportunity to fill the gap. So AR-A chose the middle model, the SME 20/2, as the candidate for what he wryly calls "the long wheelbase version."

Broadening the 20/2's chassis to accommodate a 12in arm resulted in a model deserving a new model designation: the 20/12. With the new power supply in the mix, added to the increased chassis size, the longer arm, and a larger platter than the 20/2's, SME's efforts produced what is, effectively, a new design, rather than a mere refinement. Even the chassis mass was increased, to offset any decrease in rigidity due to the extra width.

Quite unexpectedly, a non-sonic benefit emerged: the new look of the 20/12 emerged as a cosmetic makeover. As one visitor to SME noted, it looks more 'right' than the standard, almost square '20, as if the deck had been waiting all along to have its width extended. Its new proportions can be likened to those of the 20/2's, as 16:9 widescreen video images are to 4:3. But it also means that owners will need space for a record spinner with a footprint of 375x520mm, compared to the compact 320x420mm of the 20/2.

Having duly prepared just such a space, on a robust GM Accessori table, I fed the SME 20/12 and 312S into Audio Research and AudioValve phono stages. And thank goodness for detachable headshells. The one made for the 312S bolts utterly securely to the tube, so, please, let's not even re-open the fixed-vs-detachable debate. I appreciated the ease with which I could move from the Transfiguration Orpheus and Blue Angel moving coil cartridges I had been using in the SME 30/2 with Series V arm.

While I was expecting minor differences, I was certainly not ready for the slight change in character that will making choosing between the 20/12 and 312S package and the flagship 30/2 with Series V somewhat easier. It's obvious that direct comparisons are almost impossible to make because the 312S has no direct 9in equivalent, and the 30/2 doesn't exist in a long wheelbase edition. So I stopped worrying about pecking orders and just sat back to revel in qualities that were new to my ears. All of my 12in arms are of the Jurassic variety, and work well only with massive moving coils of the Ortofon SPU variety, and they're mounted on aged idler wheel decks, so the reduction in tracking error was a new sensation. And I've been living with an SME 30/2 with Series V arm for years; the sound of it is as engrained in my consciousness as that of my wife's voice.

Read more on Page 2


Because the SME 20/12 with 312S exhibits slightly less distortion due
to reduced tracking error, I noticed slightly more focus, control and
speed in the top end, a boon when listening to the exotic instruments
found on Taj Mahal's Recycling The Blues & Other Related Stuff. That
LP features a preponderance of fast and delicate sounds, many with an
almost liquid clarity, and they benefited marginally but repeatedly from
the added arm length. Both cartridges were affected by this, more so
the Blue Angel than the Transfiguration, but I also enjoyed short spells
with the Denon 103 (conical stylus) and the mono Lyra, and with both
you could still hear subtle benefits from the reduction in tracking

Hard to separate from this is the influence of the deck itself. The
performance is so stable, so grounded, so robust, that the bass acts
almost as much as a platform for the mid and treble as it serves its own
musical role. There's a solidity that doesn't just hint at the
sturdiness of the Model 30/2 - it comes so close that you'll need a
truly wide bandwidth system, with unconfined dynamic contrasts, to
appreciate the differences. Like that in the SME Listening Room.

But for all that, the most impressive aspect of the 20/12-plus-312S
machine is its sheer finesse. I've been listening to more and more
acoustic guitar lately (and for the amateur psychiatrists amongst you, I
don't know why), so it was a no-brainer digging out a mint original of
Jose Feliciano's eponymous classic and listening to his unplugged Latin
guitar work. The nuances found in his simple strumming, the air around
the performer, the sound of fingers on strings, the thumps on the guitar
body, the character of the strings themselves: if you truly value 'in
the room' realism, the SME 20/12 and 312S will allow your cartridge to
retrieve and reproduce it with alarming authenticity. This arm/turntable
combination is, by a large measure, the most graceful-sounding analogue
front-end I've ever experienced.

Please note the use of the word 'graceful' in its
dictionary-definition usage: 'elegant and easy; marked by a propriety
and fitness.' This is a turntable that doesn't just reproduce music. It
respects it.

I couldn't tear myself away from the system. For assessing its
competence with vocals, I pitted Ray Charles against Cleo Laine, with
their utterly opposing textures. They never confounded the SME
combination, and the warmth and expressiveness came through, such that
you could imagine their smiles in the studio without referring to the LP
sleeve. 180 degrees away Porgy and Bess is the fuzzy, hard rock of the
Guess Who's 'American Woman,' which was equally detail-rich, the SME
pairing managing to extract some low level information that many systems
merely skate over. Percussion was particularly seductive here; I'll
admit to having been distracted by the vocals for over 35 years, but
hearing it via the SME was educational.

At the risk of seeming lazy, I have to offer up an easy analogy to
deal with a question that will nag at some of you: whither the SME 30?
Swapping one for the other, the '30 still has that last ounce of extra
mass, slightly darker silences, slightly faster attack. Presentation is
almost identical, with both exhibiting wide and cavernous soundstages.
The line of the sound was in precisely the same position relative to the
speakers. But the 20/12 has a slightly lighter touch, the 30 more
command. Is one better than the other?

So, here's the analogical cop-out: the 20/12 plus 312S is to the 30/2
plus Series V what Porsche's Boxster S is to a full-blown 911. If you
don't know or care about cars, that means that that are so close as to
be academic, but different enough to be appreciated by connoisseurs. In
other words, the SME 20/12 plus 312S fits exactly where SME wanted it to
be in the line-up.

Although SME prefers to see the 20/12 turntable and 312S arm sold as a
package, for 11,132.63, the 20/12 can be purchased on its own for
9,724.26. This might appeal to users who already have decent arms, such
as a Series V or an M-2, both of which can be accommodated by rotating
the arm board for the 9in cut-out. But the 312S, which by deduction
costs 1,408, will only be sold to 20/12 owners. Will AR-A one day
relent, and make it available to non-20/12 owners? Don't bank on it.

Far more important a question is: will there one day be an SME 30/12?
When asked of AR-A, all you get is a twinkle in the eye. For the time
being, the 20/12 with 312S will more than suffice. Because it is, beyond
doubt, one of the three or four finest turntables on the planet. Best
of all ... it's the least expensive.

Additional Resources

* The new power supplies add clever fine-speed adjustment for all
models, plus 78 rpm and magnetic braking for the Model 10. Existing
owners of Model 10s can have their power supplies factory-upgraded,
probably through an exchange program to be determine, but the new
supplies for the Models 20/2 and 30/2 are completely different from the
originals. Existing 20/2 and 30/2 owners can, however, purchase the new
power supplies separately, without any 'trade in' allowance. All
turntables now ship with the new supplies.

100wd summary:
Prejudiced as I am toward SME turntables and arms, I can accommodate and
justify this bias with long-term experience of the 30/2 - my reference
and the reference of many other audiophiles for a number of years. The
20/12 complements it perfectly, and with the 312S it addresses the
matter of tracking error with breathtaking confidence. If behaviour at
the extreme top end and cartridge setting to a molecular level matter to
you above all else, you must audition this turntable. And once people
get used to its refreshingly sweet top end, you can anticipate a flood
of new 12in tonearms for SME's rivals.

SME 20/2 ( 4,416.67) and Series V arm ( 1,781.46): Like the man says, the 'short wheelbase' version
SME 30/2A ( 13,672.01): Still the ultimate expression of SME-ness

We listened to these LPs:
Ray Charles & Cleo Laine: Porgy & Bess (Classic/Rhino/Jazz Planet JP-1831)
The Crickets: Bubblegum, Bop, Ballads & Boogies (Philips 6308 149)
Jose Feliciano: Feliciano! (RCA LSP-3957)
The Guess Who: American Woman (Cisco LSP-4266)
Taj Mahal: Recycling The Blues & Other Related Stuff (Pure Pleasure PPAN31605)
Stevie Ray Vaughan and Double Trouble: Couldn't Stand The Weather (Pure Pleasure PPAN39304)

Review System:
AudioValve Sunilda and Audio Research PH5 phono stages
SME 10 turntable/SME Series V tonearm
SME 30/2 turntable/SME Series V tonearm
Transfiguration Orpheus, Blue Angel, Denon DL103 moving coil cartridges
Musical Fidelity Nu-Vista and McIntosh C2200 pre-amps
McIntosh MC275 power amp
Rogers LS3/5a, MartinLogan Vantage and Wilson WATT Puppy System 7 speakers
Kimber Hero interconnect
Transparent Ultra balanced cable
Transparent Reference speaker cables

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