A Near Mint GA-30 Combo

1951 Gibson GA-30 Combo

This is a near mint GA-30 Combo which puts out a healthy 14 watts. Light brown tolex covered cabinet with single wide rectangular, brown cloth bordered grill opening with "Gibson" in brass on brown cloth in center of grill. Cabinet measurements: 22 1/4 inches wide x 17 1/2 inches high x 7 1/2 deep. Weight: 27 lbs. One 12 inch Jensen Alnico 5 PM speaker stamped  "1179" & "220134" (August 1951) on casing. One 8 inch Jensen Alnico 5 PM speaker stamped "1178" & "220132" (August 1951) on casing. Two channels with one 'microphone' and three 'instrument' inputs. One "Tone Expander High/Low" slider switch. Base mounted chassis with six tubes: 2 x Raytheon 6V6GT (output); 1 x Sylvania 6SC7; 2 x Sylvania 6SJ7 (pre-amp); and 1 x Sylvania 5Y3GT rectifer. On/off switch; 2 amp fuse; 1 tone control; 2 volume controls. The potentiometers are stamped "615 0689 119" (IRC, May 1951).

This amp is in near mint condition. It has been fully serviced and the transformer has been expertly rewound. The original power cord has been replaced with a three-core cable. The GA-30 is somewhat of a 'Jekyll and Hyde' - it can be very sweet but it can also turn quite 'nasty' (in a very nice way) when pushed… it is a truly spectacular little combo. This (the first version) of the GA-30 was manufactured between 1948 and 1954.

Although the Gibson company is primarily known for it's fine guitars, the Gibson EH Series amp (late thirties) pre-dates anything made by Fender or Marshall. The Gibson amps go way back and there have been some really interesting models… "Gibson’s midline amp was changed for the third time in three years, as the short-lived GA-25 (which replaced the short-lived BR-4) was superseded by the identically priced GA-30. Cosmetically, the porthole speaker openings were replaced with a large, rectangular picture frame-style with a Gibson logo across the middle.
The 1949 Electric Guitars catalog showed the GA-30 with a two-knobbed control panel, as on the 25 (this was a new photo, not a reprint of the 25 from the ’47-’48 catalog), although most GA-30s had separate volume controls for the mic and three instrument inputs. An extra 6SJ7 preamp tube was assigned to the mic input to accommodate the extra volume control, in turn requiring the twin 6J5 phase inverter of the 25 to be replaced with a single 6SC7 to maintain a six-tube chassis. The two 6V6 power tubes and 5Y3 rectifier were basically unchanged.
A bass “Tone Expander” switch inserted/bypassed a low-frequency blocking capacitor in the negative feedback loop of the Instrument channel circuit; on the two-knob version, the switch was located on the control panel between the volume and tone controls, on the three-knob version, the mic input was moved into the row of instrument inputs and the Tone Expander was installed directly below, in its place. The deeply textured “dark brown leatherette” covering of the 25 and early GA-30s was short-lived, replaced after about a year by a smooth, light brown material. This model would run until the change to the more powerful top-mounted chassis two-tone model in 1954." (Vintage Guitar Magazine).