Sumiko RS78 Stylus for 78 RPM Records

The RS 78 — Shellac on the Cartridge You Already Own

Sumiko's 78 rpm stylus for its moving magnet cartridges, sold singly. The diamond is a bonded 3 mil spherical on an aluminum cantilever, and Sumiko describes it as “interchangeable with each of our latest MM replacement styli — Rainier, Olympia, Moonstone, Wellfleet & Amethyst.”

Three mil is roughly four times the width of a microgroove tip, and that is deliberate. A 78's groove is far wider than an LP's. A modern stylus sinks to the bottom of it and reads wear and debris rather than the record.

Fit, Profile and Compatibility

Which Bodies It Belongs On

Sumiko states it plainly: “Rainier, Olympia, Moonstone, Wellfleet and Amethyst use interchangeable stylus replacements,” and adds that “The cartridge bodies are identical with the exception of Amethyst, which uses an enhanced anatomy but remains compatible with the full range of styli.”

So one cartridge covers two libraries. The body that plays your LPs takes this assembly instead, and swaps back afterwards, with no realignment in either direction. Sumiko's own line is that “it’s never been easier to switch over to shellac when you get the itch.”

The Numbers That Matter at Setup

Sumiko specifies tracking force of 4.0 to 5.5 g with 5.0 g recommended. That is not a misprint: a 78 groove needs the weight, and it is well over double what the microgroove styli in this range ask for.

Check the arm before ordering. Some counterweights will not reach 5 g at all, and some budget arms have no calibrated scale that far up. You will also need a deck that turns at 78 and, ideally, a phono stage that can move off the RIAA curve.

See It in Action

Who Is the RS 78 Best For?

• You have shellac to play — a 3 mil sphere rides where the music was cut, not in the wear below it
• You own a Rainier, Olympia, Moonstone, Wellfleet or Amethyst — Sumiko lists all five as taking this stylus
• You want one cartridge for both formats — the swap takes seconds and disturbs no alignment
• Your arm tracks to 5 g — check the counterweight range before ordering; not every arm reaches it
• Yours is an Oyster, Pearl or Black Pearl — earlier cartridges outside this group, and each takes its own stylus rather than sharing; see replacement styli

How Do You Fit It?

Pull the microgroove assembly straight off the front of the body by its housing and press this one on until it seats. Reset tracking force to 5.0 g, change the platter speed to 78, and put the other stylus somewhere safe — you will want it back.

Pairs Well With

What most 78 players shop alongside.

• Stylus force gauges — how you set the 5.0 g this one asks for
• Speed controllers — for getting a deck to a true 78
• Stylus cleaning — what decides how long the new tip lasts
• Record cleaning solutions — a clean record is the cheapest stylus insurance there is

Frequently Asked Questions

Will it fit my cartridge?

Sumiko lists it as interchangeable with the Rainier, Olympia, Moonstone, Wellfleet and Amethyst styli, so any of those bodies takes it. Oyster, Pearl and Black Pearl are earlier cartridges outside this group.

Why does it track at 5 g?

A 78's groove is wide and its walls are steep, and shellac is a harder material than vinyl. It takes real weight to keep a 3 mil tip in contact, which is why Sumiko specifies 4.0 to 5.5 g rather than the 2.0 g the microgroove styli use.

Can I play LPs with it?

Keep it for shellac. A 3 mil sphere is far too large for a microgroove, and swapping back to your usual stylus takes only a few seconds.

How long does a stylus last?

Around 1,000 hours is the usual figure, though it turns on how clean your records are and how accurately the cartridge is set up. A worn tip damages records, so replace it on schedule rather than by ear. Shellac is more abrasive than vinyl, so expect a 78 tip to work harder for its hours.

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