Sigma Guitars are owned by C.F. Martin & Co. They created a line of inexpensive guitars in 1970, as well as their Martin guitars. Sigma guitars also have an excellent, almost legendary reputation. The electro-acoustic Sigma guitars are perfect for advancing beginners looking for an upgrade. At Guitar Galleries all of our guitars are shipped out on the same day they are ordered, with free UK delivery, after being checked over thoroughly and securely packaged by a member of our dedicated team.