Marshall Super Lead 1959 Mk II (1970) - High Treble preset

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

The 1970 Marshall Super Lead 1959 Mark II is the Unicord-era version of the 100-watt head built for the US market with four 6550 output tubes instead of EL34s. The preamp follows the plexi layout: two channels with four inputs, a gain stage and cathode follower into a treble/bass/middle stack, and a long-tailed-pair phase inverter with presence. The 6550s give it a tighter, cleaner low end and more headroom than the EL34 version.

• Made in: UK
• Wattage: 100W
• Channels: 2
• Preamp tubes: 3× ECC83
• Power tubes: 4× 6550

Tags: british, vintage, 6550, high-wattage, two-channel, 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.