Mesa Boogie Mark IIC+ - Rhythm preset

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

The Mark IIC+ occupies a singular position in amplifier history — widely regarded as the finest high-gain amplifier ever made in production, it combined extraordinary gain depth with a musical, three-dimensional character that no subsequent design has fully replicated. Five 12AX7 preamp stages feed into Mesa's proprietary printed circuit board layout, which was so carefully engineered that Metallica's engineers studied its topology extensively when specifying replacements. James Hetfield and Kirk Hammett tracked every Metallica album from Kill 'Em All through ...And Justice for All on IIC+ heads; John Petrucci made it his reference amp for Dream Theater's progressive metal work; original units now command prices above $10,000 on the used market. Its lead channel achieves a singing sustain and harmonic complexity — particularly in the upper midrange — that rewards technical playing in ways that later high-gain amps rarely match.

Known for: James Hetfield (Metallica), Kirk Hammett (Metallica), John Petrucci (Dream Theater), Carlos Santana.

Heard on: Master of Puppets — Metallica (1986); Fade to Black — Metallica (1984); Pull Me Under — Dream Theater (1992).

Tags: american, high-gain, 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.