The Gibson GA-18 was added to Gibson’s tweed combo amp line in 1959 but was only on the market for about a year. This model featured tremolo but did not reflect it in the model number, as Gibson normally used a letter suffix to denote features like reverb (RV) and tremolo (T). Reported sales figures for 1959 are 1,421 units. The GA-18T model took it's place in 1961 (thru 1963) and is nearly identical except that the GA-18 has a 12 inch Jensen alnico speaker while the GA-18T has a 10 inch Jensen alnico speaker. Most Gibson amps from made from 1955 to 1965 can really deliver a great tone comparable to many classic Fender models, but usually require some important circuit modifications. Vintage Gibson’s are great candidates for restoration/mods because;
