Mesa Boogie Mark I - Lead preset

Verified · 82/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Mesa Boogie Mark I was the amplifier that started it all — Randall Smith's heavily modified Fender Princeton circuit that stunned Carlos Santana and ignited the boutique amp industry. Its cascading gain stages produced a smooth, singing sustain that was entirely unlike anything available from Fender or Marshall at the time, bringing violin-like sustain and singing harmonics to the guitar. The Mark I remains one of the most historically significant amplifiers ever built.

• Years produced: 1969–1982
• Made in: USA
• Wattage: 60W
• Channels: 1
• Preamp tubes: 3× 12AX7
• Power tubes: 2× 6L6GC

Known for: Carlos Santana, Lowell George.

Heard on: Black Magic Woman — Carlos Santana (1970).

Tags: american, vintage, crunch.

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.