Sumiko Oyster MM cartridges: Shucking the sonics

That’s shucking, not shocking – specifically, the act of opening an oyster’s shell to get to the meaty bits inside. And in many ways, that’s exactly what this new trio of Oyster moving magnet cartridges from Sumiko manages, while offering a clever upgrade path, too.

By Deon Schoeman


I’ll be the first to admit that oysters aren’t my thing. I prefer my food cooked, and the thought of lifting a salty, slimy bi-valve out of its shell and swallowing it whole doesn’t really appeal.

The fact that you need a good squirt of Tabasco to help it down (and a glass of decent bubbly to get rid of the taste) should tell you everything. Yes, I know, I’m a Philistine when it comes to molluscs.

But not all oysters are shuckable. In the case of Sumiko’s newly launched Oyster Series, we’re not talking the shelled variety, but phono cartridges, as eclectic as that association may seem. Of the six newcomers, four are moving magnet designs, with two moving coil models topping the range.

The three most affordable models offer an interesting, if not unique, selling proposition: you can start off with the entry-level model, and then upgrade to the dearer versions simply by swapping out the stylus: all three share the same cartridge body.

The entry-level Oyster model is the Rainier, followed by the Olympia and the Moonstone. In case you wondered, the names are taken from actual oyster species cultivated in the US.

For the record: Rainiers are full and firm with a buttery texture, Olympias are small on size and big on flavour, and Moonstones are briny with a rich umami taste – according to The Raw Oyster.

Just how that translates into sonic terminology remains to be seen, but it did prompt me to audition all three cartridges, and compare their sonic virtues relative to their price point – as well as the viability of the upgrade path. And besides, I didn’t have to swallow anything raw in the process!


As already mentioned, all three cartridges are moving magnet designs, and share the same, newly designed body. Not surprisingly, the actual housing is made of inert, non-resonant plastic, and contains an integrated motor system to further combat resonance.

The Rainier’s stylus features a white surround, and combines an elliptical diamond tip that’s bonded onto an aluminium cantilever. So far, so good.

A glance at the spec sheet shows a generous 5 mV output, together with the customary 47 kohm load impedance typical of all moving magnet cartridges. The Rainier weighs in at 65 grams.

The Olympia replaces the white Rainier stylus with a green one that, colour aside, looks exactly the same. But don’t be fooled: there are significant differences.

The aluminium cantilever has a bespoke design, and the diamond tip retains the elliptical shape, but gains a more precisely polished profile. The magnet, which forms part of the stylus assembly, is slightly smaller, accounting for the drop in output from 5 mV to 4 mV.

The result should be a better fit into the LP groove, and improved tracking ability, with potentially better information retrieval. The Olympia’s specs show an extended frequency response and improved channel separation to underline this.

Moving up one more rung brings us to the Moonstone, which has the smallest magnet, dropping output further to 3 mV. Again, the cantilever is unique to this cartridge, and the elliptical tip gets an even more polished, more precise profile.

A glance at the specs shows further, commensurate improvements in frequency response and channel balance, vindicating the Moonstone’s elevated status and asking price – on paper, at least.

At 6 grams, all three cartridges should be compatible with most light to medium tonearms, ensuring a wide application field.


A quick note on the reasoning behind fitting lighter magnets as you move up the Oyster ranks. As in all MM cartridges, the magnet in question is mounted at the far end of the cantilever, which vibrates according to the diamond tip’s movements in the vinyl record’s groove.

The magnet is located between the two coils of the cartridge’s motor system, integrated into the cartridge body. As it vibrates, the movement induces a current in the coils, creating the signal which we ultimately hear as the music embedded in the vinyl record.

A lighter magnet translates into more accurate movement, and therefore enhanced detail retrieval, albeit at the expense of output voltage. That said, most modern, good-quality MM phono stages should be well up to the task of stepping up a 3 mV signal without revealing any noise issues.


The Oysters come nicely packaged in wooden boxes with cardboard wraps, and included mounting hardware. The angular bodies have integrated threaded sockets for the mounting screws, making mounting them on a headshell a simple affair. The angular shape also eases alignment.

In the interests of ensuring efficient and effective back-to-back comparisons, I stuck with a single cartridge body for this test, simply swapping the stylus, rather than mounting an entirely different cartridge each time. As the weights and dimensions are identical, there was no need to reset VTA, azimuth, alignment or tracking force each time I swapped styli, either.

The test was conducted using my trusty Avid Diva II SP turntable fitted with an SME 309 tonearm. Looking after phono amplification was a Sutherland 20/20 set to 47 kOhms and 46 dB of gain. The rest of the system comprised an Electrocompaniet EC 4.7 pre-amp, PS Audio Stellar M700 monoblocks, and Vivid Audio V1.5 loudspeakers, with cabling by TelluriumQ.


Starting off with the entry-level Rainier, first impressions were of a quiet background with no surface noise to speak of, a generous and accessible staging with plenty of dimensional pointers, and a rich tonal character that added real meat to the music’s bones.

There was a certain smoothness to the delivery that wasn’t merely analogue in character, but added to the music’s accessibility and enjoyment without robbing it of sparkle. Yes, there could have been a bit more fizz and excitement, but the there was a truthfulness to the music that made listening both engaging and unfatiguing.

The Rainier coped well with the extended low frequencies of The Cowboy Junkies’ classic The Trinity Sessions, easily recreating the atmospheric and reverberant ambience of the recording venue, and precisely placing instruments and voices on the seamless, holographic soundstage.

Margot Timmins’ voice had just the right sheen, the guitar was delivered with vivid presence, and the acoustic bass sounded muscular, but wasn’t allowed to dominate.

An older pressing of Beethoven’s Violin Concerto in D Major, lyrically interpreted by the great Wolfgang Schneiderhan and the Berlin Philharmonic under Eugen Jochum’s fluid baton sounded thrilling in the Rainier’s care.

It managed express both the majesty and the soulfulness of the music, allowing the power and dynamics of the orchestra free rein, but also highlighting the tenderness and delicacy of the quieter passages.

Schneiderhan’s violin was presented with riveting realism, always enjoying sonic pride of place, yet perfectly integrating into the overall sound picture. The large, seemingly limitless stage provided ample air and space for the orchestra, creating a dimensionally true and realistically scaled music image.

The sheer pace and dynamics of guitar duo Rodrigo Y Gabriela on their eponymous album makes for thrilling, adrenaline pumping listening – but it can also sound bright, attacking and muddled on systems not up to the challenge.

The Rainier had no such problems, retaining balance and composure without blunting the attack and pace of the music. It seemed to revel in the rich timbre of the guitars, and wasn’t in the least intimidated by the often frenetic percussive effects.

Again, staging was transparent and wide open, allowing the music to live and breath, while pinpoint imaging endowed the performers with an almost physical presence. The music was delivered with real punch and substance, but the more delicate details weren’t glossed over, either.

The original Dire Straits debut album remains one of my favourites, both sonically and musically. It has a freshness and honesty that brings the music to the listener with undiluted passion – and the Rainier capably expressed that authenticity.

Mark Knopfler’s agile yet lyrical lead, the splashy rhythm guitar, the almost hollow but steady electric bass and the explosive drumwork on ‘Down To The Waterline’ were all done full justice, carefully presenting each instrument on a well defined, immersive sound space.

Moving on to the Olympia, the differences were immediately apparent. While the Rainier presented the music in broad, bold and engaging swathes of sound, the Olympia offered greater insight, closer attention to detail and a tonal signature that provided all the warmth, but added more icing and detail to the higher frequencies. The result was a sound that was still smooth and accessible, but also cleaner and more attentive.

The Dire Straits recording sounded even livelier and more vibrant, and the rhythm guitar was given more stature, allowing for a better balanced overall sound. Imaging remained precise, but there was more musical information to fill in the overall picture, making for a more wholesome, and more realistic sound.

As entertaining as the Rainier was, key aspects – tonal richness, quiet backgrounds, great dynamics – were all brought into even closer focus, making for an ultimately more engaging, and more fulfilling, listening experience.

Those same trends were obvious when listening to the Beethoven Violin Concerto. Again, all the power of the orchestra, and the sweeping vistas of the music, were there, but the Olympia simply made more of what was in the groove, adding subtleties and filling in hues and textures that had remained obscured under the Rainier’s care.

There was better control of passages where the orchestra as in full cry, and an additional nimbleness and pace to the delivery, while the solo violin gained a more defined body and presence. The sound was more ‘coloured-in’ than before, and the greater attention to detail extended to additional spatial cues that allowed a more emphatic sense of space and air.

That’s not to say that the Rainier was poor – anything but. However, the Olympia was able to raise the sonic stakes significantly.

Last but not least, the Moonstone made its way onto the SME 309 – and the step up in sound was a lot more succinct than I had expected. If I had to describe the difference in one word, it would be refinement.

The Moonstone shone a brighter but benign light on the music, lifting out further slivers and shards of detail, but contextualising these with such a sense of balance and integrity that the sound picture became even more compelling and musically engaging than before.

There was a marked step up in treble detail and sparkle, but without turning the view of the music into a clinical appraisal: the tonal equilibrium was maintained, and the high frequency delivery was silky rather than brilliant.

Certainly, the tonal progression was delivered in finer, sleeker increments, adding body without bloating the sound. With the Berlin Philharmonic in full cry, I could hear (and feel) the double bass section, appreciate the freely soaring strings, and pick out the melancholy woodwinds with ease.

The Moonstone easily maintained the percussive edge and sheer pace of Rodrigo Y Gabriella’s energetic guitars, but here too, there was a sheen of sophistication, a completeness and a sense of composure that couldn’t be matched by the other two Oysters.

The hard-edged guitar work was qualified by those same, expanded textures and hues, adding further life and colour to the music. The instruments sounded more lifelike – more alive, more real – than before, and while the warmth and wholesomeness of the Oyster house sound was maintained, the overall signature was smoother and more progressive.


That the Moonstone should be the best cartridge here should come as no surprise. But what is surprising is that such succinct differences can be achieved simply through better cantilever and stylus tip construction.

Of course there’s more to it than that: it’s the bespoke combination of tip, cantilever and magnet, together with the quality of that elliptical diamond tip, that makes the difference. And let’s not forget that a solidly engineered cartridge body and motor system are vital building blocks, too.

The combination of completeness and insight afforded by the Moonstone places it in a completely different league. Yes, it easily outshines its two siblings here, but its target market is already elevated beyond the entry level.

In sheer value terms, the Olympia gets the nod. The sonic advantages it offers relative to the extra R1k on the price tag makes it the best buy of the trio. The step up is significant, more than warranting the extra investment.

But let’s not underestimate the Rainier. Lively, exciting, punchy and thoroughly entertaining, it offers a lot of musical bang for the buck. And once your budget allows an upgrade, moving up to Olympia or even Moonstone status is only a swap of a stylus away.


Sumiko Oyster Rainier: R2 790
Sumiko Oyster Olympia: R3 790
Sumiko Oyster Moonstone: R5 690

Croak Audio Exploration

Cowboy Junkies – The Trinity Sessions (Analogue Productions/Sony Music 180g LP)
Rodrigo Y Gabriela – Rodrigo Y Gabriela (Rubyworks/Music On Vinyl 180g LP)
Beethoven – Violin Concerto in D Major – Schneiderhan/Jochum/Berlin Philharmonic (DGG LP)
Dire Straits – Dire Straits (Warner Brothers LP)
Hugh Laurie – Didn’t It Rain (Warner 180g LP)

Avid Diva II SP/SME 309/Van Den Hul The Frog
Sutherland 20/20 phono stage
Electrocompaniet EC4.7 pre-amp
PS Audio Stellar M700 monoblocks
Vivid Audio V1.5 loudspeakers
TelluriumQ Black cabling
PS Audio P5 power regenerator