G12M Greenback 1969

To replace the alnico magnet G12s, an iron-based ceramic became a suitable alternative that was used in models from 1965. The first of these models were the T1220 (8ohm) and T1221 (15ohm), described in the T-book as having a plastic can, which turned out to be an olive-green cup that fitted over the magnet assembly.

These new G12 speakers had also been constructed slightly different from the original alnicos, with kraft paper being used for the voice coil formers in preference to cartridge paper. This modification, along with the greater surface area of the ceramic magnet assemblies, afforded the speakers a little more power handling. The first G12Ms were rated at 20W (and revised to 25W a couple of years later) making them more robust and leaving a little more ‘headroom’ when used with a higher-power amplifier.

Affectionately referred to as ‘Greenbacks’ (because of the rear-mounted can’s colour), the G12Ms quickly caught the imagination of Marshall and its growing legion of soon-to-be-legendary players, from Jimi Hendrix, Eric Clapton, Jimmy Page, Jeff Beck and Paul Kossoff – quickly replacing the alnico G12 to become the standard speaker.

The G12M offers rich, vocal midrange, a well-articulated treble, and a warm, controlled low end, with plenty of crunch and compression if you dig in; delivering the original Greenback tone.

This superb collection of speaker responses has been recorded using some exquisite examples of the G12M Greenback, dating from 1969 and taken from Celestion’s extensive archive.