Gibson GA 20

1950 Gibson GA 20 Combo

A very good condition GA-20 survivor which puts out a healthy 12-14 watts. Light brown leatherette covered cabinet with metal G badge in the center of the grill, The power transformer code 166026 indicate a July 1950 production and the 12 inch Jensen Alnico 5 speaker is stamped P12R C5496 220029, also July 1950.

The amplifier was recently brought back to specification by Mid Century Audio. The chassis has been completely gone through with new electrolytic caps and filter caps - however the original cap covers were retained and re-stuffed with new Sprague and Mallory caps to retain the original look. A few drifted resistors were also replaced. All the pots were de-oxitized and are scratch free. A 3-prong grounded power cable was fitted to make the amp safe. (The original 2 prong cable is available for those who want to retain the original) There are six tubes: 2 x NOS 6V6GT (output); 1 x AMPEG 6SL7GT (phase splitter); 2 x NOS JAN-6SJ7 (pre-amp) and 1 x 5Y3GT rectifier. On/off switch; 2 amp fuse; 1 tone control; 2 volume controls.
When we obtained the amp the Jensen's speaker coil was burnt out and the speaker was re-coned by Speaker Repairs Pros (formerly OC Speaker).
This amp is in good condition - a survivor - for it’s almost 70 years with some obvious wear on the corners and some discoloration and stains in a few areas, but it is a solid redwood cab (please see all the pictures). Care was taken to retain as much of the “patina” that the amp has. Any loose edges of the original leatherette covering was glued down to prevent further wear. The original grill cloth is in great condition and intact with no holes or snags. The faceplate shows some pitting, scratches and rust spots as does the metal on the handle. A new leather handle was fitted that is very similar to the original. The back panel was missing but a new one was made and covered in a tan leatherette that was color matched to the amp.

The GA-20 is a two-headed monster of tone - it can be very sweet but it can also turn quite 'nasty' when pushed. Many players use the normal inputs for clean sound but plug into the instrument channel to push the amp in to some great sounded grit.