prior to selling the brand to AMI, and had since been picked up by St. rights to the Sigma brand name and trademark had been allowed to lapse by C.F. The rights to the name were acquired by German company AMI Musical Instruments GmbH, which relaunched the brand with guitars being produced in China. The Sigma line was discontinued by Martin in 2007. Martin as a line of guitars at affordable prices to compete with the increasing number of imported guitars from Japan and elsewhere. Sigma Guitars is a guitar manufacturing brand originally released by C.F. ( Learn how and when to remove this template message) ( September 2022) ( Learn how and when to remove this template message) Several templates and tools are available to assist in formatting, such as Reflinks ( documentation), reFill ( documentation) and Citation bot ( documentation).
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