Hiwatt SA412 - Brilliant preset

Verified · 93/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Hiwatt SA412 is a mid-1970s two-channel combo in the Custom layout. Brilliant and Normal channels each have two inputs, a 12AX7 stage and their own volume, mixing into a further 12AX7 stage, the Hiwatt treble, middle and bass stack, a master volume and another gain stage. A 12AU7 long-tailed-pair inverter with presence drives two fixed-bias EL34s into a Partridge transformer from a 460-volt solid-state supply. Clear and tight.

• Made in: UK
• Channels: 2
• Preamp tubes: 3× 12AX7, 1× 12AU7
• Power tubes: 2× EL34

Tags: british, vintage, clean, el34, two-channel.

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.