Gibson Ga 40 Les Paul With 5879 preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

This variant of the GA-40 Les Paul combo uses 5879 pentode preamp tubes rather than the more common 12AX7, resulting in a distinctive tonal character with a more aggressive, forward midrange presence. The 5879 was a military-spec pentode adapted for audio use, and its use in this circuit gives it a unique voice among Les Paul-era amplifiers. Paired with a 6L6 output stage, it produces bold, punchy clean tones that sit differently in a mix compared to triode-preamp designs. This is an important early Les Paul amplifier variant for collectors and historians.

• Years produced: 1952–1956
• Made in: USA
• Wattage: 14W
• Channels: 2
• Preamp tubes: 1× 12AX7, 2× 5879
• Power tubes: 2× 6L6

Known for: Les Paul.

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.