Early Yamaha SG 12 string Guitars

The SG12 and the SG12A. The first is a 12 string version of the SG3 and the second a 12 string version of the SG5A

The SG12

Specifications
Body High Gloss Poly finish unknown wood*
Neck Bolt on Maple
Fretboard Rosewood 22 frets with a zero fret
Headstock see pictures
Tuners Chromed covered Yamaha branded "Pincushion type"
Pickups 3 single coils
Controls see below
Nut Chrome covered unknown width
Hardware Chrome
Bridge Tune O Matic roller type with Yamaha adjustable trem unit see SG first page
Pickguard white or off white
Colours Sunburst, Pearl White or Coral Red
Years available 1966 to 1967

* A seller on the Yamaha musicians forum said it looked to be made of Japanese Judas Wood I have no idea if this is the case or not.

Controls The SG12 has two circuits (rhythm and lead) so you can set up two different tones on the guitar and switch between them,. The volume and tone controls on lower part of the guitar work in the usual way for the main circuit, but the switch nearest the point of the upper horn allows you to select the alternate circuit which has separate volume and tone “wheels” just above the neck pickup. A blender switch combines the two bridge pickups in various ways. There is also a 3 way pickup switch
Pickups
Yamahas literature describes these as having new anisotrophic ferrite magnets in order to ensure a consistent tone at all volume levels.
I assume that the 12 has the same bridge pickup arrangements as the SG3 here is a comment from a guitar magazine review for the SG3
Those are actually two single-coils in that humbucker-looking housing, but they are differently designed. The one closest to the bridge has an extra magnet under the coils and then a metal bridge plate under that. The bridge pickup is just meaner and more aggressive than the other ones. It's a cool idea when paired with the roller control on the upper bout.

Some Pictures

The Sunburst



Close Up of the Body and Controls

The headstock

The 12A

A 12a in Pearl White

This is a completely different guitar to the 12. It has the extended lower horn of the second series and some of the first series. The headstock is a slightly different shape and the electronics are different it doesn't have the dual circuit facility.
Specifications
Body High Gloss Poly finish unknown wood*
Neck Bolt on Maple
Fretboard Rosewood 22 frets with a zero fret
Headstock see pictures
Tuners Chromed covered Yamaha branded "Pincushion type"
Pickups 3 single coils as SG12
Controls 1 volume 1 tone a blender for the 2 bridge pickups and a 3 way switch
Nut plastic unknown width
Hardware Chrome
Bridge Tune O Matic roller type with Yamaha adjustable trem unit see SG first page
Pickguard White or off White
Colours Sunburst, Pearl White, Candy Blue or Coral Red
Years available Nov 67 to 1971

Pictures


The string bar isn't original

Reissue
In 1996 there was a reissue of the 12A styled as the SG12AS (Anniversary Special) Detail of this guitar is hard to find so whether there are any significant differences is hard to determine.