Gibson GA-8T Head
Gibson GA-8T Head
The GA-8T was a 1961 tweed era combo using a pair of 6BM8 triode/pentodes, with the pentode sections in push-pull for an output of 8W. It used a solid state rectifier, 12AX7 pre-amp, one of the 6BM8 triodes as phase inverter, and the other as the tremolo oscillator. My compact head version used mostly re-cycled parts, including a steel enclosure which had a previous life as a Queensland University lab test instrument.
Looks like a crazy mess, yeah? It was certainly a fiddly job.
Does it work? Hell yeah. Here's a YouTube video of Mike Frost test-driving...