Just picked up my first Sigma - a DR-7 with Rosewood sides and 2 piece back and looks like spruce on the top. The serial number is in the 11,000's and it's the original style with the paper label and the sideways M on the head. Probably '73 or so?

Someone was giving it away on craigslist . . I happened to just be in the right place at the right time - the woman who owned it told me the strings were too far off the neck to be played, and a local music store told her the neck was warped and couldn't be fixed.

Anyway, it ends up that the top is just bowed out a little behind the bridge and the neck isn't warped at all. Probably has been leaning on a wall for the last nn years with some Black Diamonds on it.

It sounds as big as a Martin and the workmanship is just fine.
I remember when Martin came out with the Sigmas. They didn't really strike me as being a "low end" guitar and were priced along with the high - mid range instruments. I mean - I bought a Martin D 12-20 for a little over $300 and the Martin D45's could be had for just over a thousand bucks at the time.

I buy and sell guitars mostly, but after looking at what these are going for on eBay (200-300) I might just keep it. There is not a guitar out there anywhere right now that has the quality and big sound that this has for less than a grand.