What tubes does the Gibson GA-83S Preamp - Normal use?

The Gibson GA-83S Preamp - Normal uses 4× 12AX7 preamp tubes and 4× 6L6 power tubes.

When was the Gibson GA-83S Preamp - Normal produced?

The Gibson GA-83S Preamp - Normal was produced 1959–1963.

Gibson GA-83S Preamp - Normal preset

Close · 72/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

This schematic covers the preamplifier section of the Gibson GA-83S Stereo, documenting the dual-channel preamp topology that feeds the amp's two independent power stages. The preamp uses multiple 12AX7 stages to develop the signal for stereo output, with tone controls and channel switching handled before the signal splits to the independent power amplifiers. Understanding this preamp stage is key to appreciating how Gibson achieved true stereo sound in a guitar combo in the late 1950s.

Years produced: 1959–1963
Made in: USA
Wattage: 40W
Channels: 2
Preamp tubes: 4× 12AX7
Power tubes: 4× 6L6

Tags: american, clean, vintage.

Schematic-derived preset files for 16 Fractal and Line 6 modelers: Axe-Fx II/XL/XL+, Axe-Fx III, FM3, FM9, and the full Helix family (Floor, LT, Rack, HX Stomp, HX Stomp XL, Native).

Gridleak extracts amp parameters from original circuit schematics using AI vision — component values, gain staging, tone stack topology, tube types — then generates native preset files for every supported modeler. Every extraction is scored 0–100 and the score is published.