Gibson EH-125 (6SJ7) preset

Verified · 92/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

This is the later wartime version of Gibson's EH-125, which replaced the 6SQ7 front end with a 6SJ7 pentode preamp. The pentode feeds a 6J5 split-load inverter and a pair of 6V6GT output tubes, with a 5Y3 rectifier and a field-coil speaker. The result is a small, warm prewar-style amp that breaks up early.

• Made in: USA
• Wattage: 15W
• Channels: 1
• Preamp tubes: 1× 6SJ7, 1× 6J5
• Power tubes: 2× 6V6GT

Tags: american, vintage, 6v6, low-wattage, breakup.

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.