Sigma Guitars
Sigma Guitars started manufacturing in January of 1970, Martin Guitars started the Sigma brand to compete with the flood of Japanese models that hit the US market in the late 60s. Martin’s US factory struggled to keep up with demand at the time due to the time lag needed to season hardwoods. The first Sigma models were manufactured out of Japan from 1970 through to 1983 before moving their operation to Korea 1984 to 1993 and then to Taiwan in 1994 before moving to Indonesia in 2007.
All the Sigma Guitars that came into the US from 1970-2007 were inspected by Martin guitars before going out to retail stores.
SIGMA Generation III Ad
Sigma also had a short period where they had two models produced in the US. This was between 1981 and 1982. Martin imported Sigma parts from Japan and finished the assembly in Nazareth, Pennsylvania. The two models are labelled "Sigma Martin USA” DR-28N and DR-35N. The 'N' was for "Nazareth". There is evidence that just under 3000 models got released in the US.
SIGMA D28 1981
It was in 2007 that Martin sold the Sigma Brand to a German Company called AMI Musical Instruments. Whilst the legendary Sigma brand lives on in Australia and most other parts of the world, it was not quite smooth sailing for the American Market. This was due to the fact that the Sigma Brand and Trademark had been allowed to lapse prior to the sale to AMI. St Louis Music in the US had purchased the rights, and now AMI is not allowed to use the Sigma brand in the US. The Guitars are still sold in the US; however, they carry the Parent Companies branding of AMI on the headstock.
AMI Headstock USA Market
The resurgence of Sigma guitars in the current guitar market has come down to the amazing quality of the guitars with an attractive price point. The quality of Sigma Guitars has always been its selling point for those looking to purchase in the mid-range market.
While Martin's decision to sell Sigma Guitars may have helped Martin strengthen its position in the marketplace with 100% of its time dedicated to its main brand, one can only notice that this was also the same for Sigma (AMI), with customers seeing some of the best Guitars the company has ever offered over recent years.
1 comment
Andrew Stirling
I purchased a new Sigma SDM 10E crossroads series dreadnought acoustic guitar in December 2025 with the solid spruce top solid mahogany back and sides LR baggs pickup bone nut and saddle and grover nickel open tuners I was blown away by the amazing sounding tone of this particular model it is really loud and clear whether playing rhythm or fingerpicking it just sounds so good I only bought the Sigma for something different to play with as I already have several acoustics I have a new Gibson Montana J45 standard a Taylor GTe urban ash acoustic a Taylor 117e Grand Pacific acoustic and a Fender California series 12 string I absolutely love this Sigma It is definitely a keeper I love it as much as my other acoustics I also swapped the strings for the new Martin long life 2 phosphor bronze light and changed the original plastic bridge pins for the Crosby bone pins with the shiny Abalone design on top I normally use d,darrio eJ or XS strings but I just wanted to try the new Martin strings on the Sigma I do also like Martin guitars and I am hoping to own a D28 sometime in the future once I have cleared the finance on my new J45 Anyway I really love my Sigma and I haven’t put it down since I bought it fantastic value for the price and amazing quality I paid £849 GBP for mine I got a £50 discount from the guitar store amazing guitars Andy Glasgow Scotland 🥰🥰🏴