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Sigma Guitars article

A Guide to Sigma Guitars

Born as Martin's answer to Japanese competition in 1970, relaunched by a German company in 2011 — here's the real story behind Sigma Guitars.

A Guide to Sigma Guitars

There's something quietly romantic about a brand born purely out of competition, and Sigma Guitars is exactly that story. It started life as one company's answer to a threat from the other side of the world, went quiet for a few years, and came back under completely different ownership. Here's how that all actually happened, and what it means for the guitars carrying the name today.

Born From Competition, 1970

By the late 1960s, Japanese manufacturers were turning out acoustic guitars that were genuinely competitive on quality, at prices well below what American-made instruments could match. C.F. Martin & Co. — yes, that Martin, the Pennsylvania company behind some of the most revered acoustics ever built — responded not by cutting prices on its own line, but by launching an entirely separate value brand in 1970. That brand was Sigma, built on familiar American steel-string shapes at a price point Martin's core range simply couldn't reach.

This is the bit worth getting straight early, because it trips people up constantly: Sigma guitars were never built in Martin's Nazareth, Pennsylvania factory. They drew heavily on Martin-associated body shapes and model conventions — dreadnoughts, 000s, smaller-bodied instruments — but "Martin-designed" and "Martin-made" are genuinely different claims, and specifications varied a good deal by production period and factory.

A Quiet Ending, and an Unexpected Second Life

Martin stopped supplying Sigma distributors in 2003 and wound the brand down in the American market entirely by 2007. That could easily have been the end of the story. Instead, German company AMI Musical Instruments GmbH bought the Sigma naming rights in 2011 and relaunched it, with production resuming in China according to AMI's own historical account. Today's Sigma is best understood as its own value-oriented acoustic brand with genuine Martin heritage behind it, rather than a current Martin subsidiary or budget line.

What's in the Current Sigma Guitars Range

AMI's European catalogue spans a proper spread of acoustic formats: dreadnoughts, orchestra and 000-style bodies, parlour guitars, travel instruments, acoustic-electrics and nylon-string models. Recognisable current names include the DM-18, 000M-18, DT-28H, 000T-28S and TM-12, alongside acoustic-electric models like the SGMC-10E and SGPC-10E. If you're trying to work out which of these actually suits you and your budget, our best-value breakdown goes through the current line-up properly.

What They're Actually Built From

Body styleCharacterGood for
DreadnoughtLarge body, strong projection, substantial bassStrumming, flatpicking, bluegrass
000/OM-styleSmaller waist, more balanced responseFingerstyle, recording, comfort
Parlour/small bodyCompact, focused midrangeBlues, folk, intimate playing
Nylon-stringWider neck, classical stringingClassical, Latin, fingerstyle

AMI states that its current Sigma instruments use solid tops with bone nuts and saddles as standard, with gloss models finished in UV lacquer and select limited editions using nitrocellulose — genuinely respectable specification territory for the price bracket the brand sits in.

A Word of Caution on "Sigma Guitar" Listings

Because the name has covered three genuinely different eras — early Martin-era imports, later Asian-made instruments, and the post-2011 AMI relaunch — a listing simply reading "Sigma Guitar" tells you almost nothing about its age, factory or exact specification. Country of manufacture, materials and build quality all shifted across those decades, so treat the model name as a starting point for research, not a guarantee. Our buyer's guide covers exactly what to check before you commit to either a vintage or current example.

Who Sigma Actually Suits

Players after genuine steel-string acoustic tone and traditional construction without flagship pricing, anyone drawn to the brand's Martin-adjacent history, and buyers comfortable doing a little homework on production era and specification rather than assuming every Sigma is identical. New to acoustic guitars generally? Our beginner's guide is the friendlier starting point.

The Bottom Line on Sigma Guitars

Sigma's story is really two brands wearing one name — a Martin-born 1970s value line, and a German-owned relaunch carrying that heritage forward since 2011. Both eras have produced genuinely good instruments and some best avoided, which makes a bit of background research more useful here than with almost any other acoustic brand you'll come across.

Frequently Asked Questions

Who originally created Sigma Guitars?

C.F. Martin & Co. founded the brand in 1970 as a lower-priced line to compete with increasingly capable Japanese imports.

Were Sigma guitars made in Martin's factory?

No. They were built outside Martin's Nazareth, Pennsylvania factory, mainly in Asian production centres, despite drawing on Martin-associated designs.

What happened to the brand after Martin?

Martin discontinued Sigma in the American market by 2007. German company AMI Musical Instruments GmbH acquired the naming rights in 2011 and relaunched it, with production in China.

What materials do they use today?

AMI states its current range uses solid tops with bone nuts and saddles as standard, with UV finish on gloss models and nitrocellulose on select limited editions.

What body shapes does the current range include?

Dreadnoughts, 000/OM-style guitars, parlour models, travel guitars, acoustic-electrics and nylon-string instruments.

Is a Sigma the same as a Martin?

No. Sigma has Martin-related design heritage but is a separate brand, and a similar model number doesn't guarantee equivalent materials or specifications to an actual Martin.

About Charlotte Bennett

Charlotte grew up in a house where the record player was never off, and turned a teenage habit of scribbling gig reviews into a career spent writing about the music she loves. Based in London, she still spends her weekends digging through the crates in the city's second-hand shops and catching new bands in small rooms before anyone else has heard of them. She writes about guitars, records and the stories behind the songs.

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