Sunn 100S preset

verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Sunn 100S is an early head from the Sundholm brothers' Oregon company, a Dynaco-derived design voiced for big, clean low end and high headroom and widely used for bass as well as guitar. A 12AX7 preamp with Volume, Treble, Bass and Contour feeds a 6AN8 pentode gain stage and triode cathode-coupled inverter, with feedback from the 16-ohm tap, driving two fixed-bias KT88s from a GZ34 rectifier with choke and standby. The June 1967 version adds Normal/Bright inputs, a 12AU7 spring reverb and transistor tremolo; the November 1967 version drops them.

Tags: american, vintage, 6550, bass, clean.

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.