In the mid-'50s, the electric guitar was taking off! Everyone knows that Gibson was a leader in the development of the electric guitar. But even though their amplifiers produce fantastic tone, Gibson amps have never commanded the high values of comparable vintage brands. Because of that, a good Gibson amp can deliver authentic vintage tone and mojo at a much more accessible price.
The GA-6 was essentially Gibson's answer to the tweed Deluxe. By 1956, it featured a 12-watt design with a 12" Jensen speaker. Its preamp is driven by one 12AY7 and one 6SL7, and its power section features two 6V6s and a 5Y3 rectifier tube. With four inputs and two channels (three for the instrument channel, one for the microphone channel), the GA-6 delivers classic American tone.
This circa 195 GA-6 is a great example of a classic old Gibson amp—nothing looks as cool as the mottled gray-brown covering! Its original Jensen P12R Alnico dates to the 49th week of 1955. Over the years, the Gibson logo and "6" badge have been lost from the front. Three filter caps have been replaced with modern F&T capactiors, one of the back panel screws has been replaced, and it also sports a safe three-prong power cord for modern use. All remaining parts—down to its leather handle—appear to be original and still function as they should. It also includes its original instructions/specifications sheet.
Plugged in, this 1956 GA-6 has a reedy, woody tone, and it has quickly become one of the favorites around the shop. Relative to Fender tweed amps, Gibsons tend to have a milder, smoother output that stays cleaner as you push the volume. With single coils, this GA-6 starts to break up around 10:30-11:00 on the volume knob, which provides some nice clean headroom. When it starts to break up and saturate, it's smooth and not as aggressive as other tweed circuits. The overall EQ has a prominent midrange and strong harmonic content while remaining warm (no risk of ice-pick trebles). Great amp!