What tubes does the Gibson GA-75 (early) - Normal use?

The Gibson GA-75 (early) - Normal uses 3× 12AX7 preamp tubes and 4× 6L6 power tubes.

When was the Gibson GA-75 (early) - Normal produced?

The Gibson GA-75 (early) - Normal was produced 1955–1960.

Gibson GA-75 (early) - Normal preset

Close · 68/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The original GA-75 is one of Gibson's most ambitious amplifiers of the 1950s, pushing around 50 watts through four 6L6 output tubes in a large twin-speaker combo cabinet. Built for professional stage and large venue use, it delivers massive clean American tone with exceptional headroom. Two channels cover rhythm and lead duties. The GA-75 original is a rare and significant vintage amplifier representing the peak of 1950s Gibson amplifier engineering.

Years produced: 1955–1960
Made in: USA
Wattage: 50W
Channels: 2
Preamp tubes: 3× 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.