Supro S6688 - Tremolo preset

Verified · 87/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Supro S6688 is a two-channel Valco combo. The Standard channel and the Tremolo channel each have their own volume and tone control, with high and low inputs on both. A 12AX7 tremolo oscillator offers speed and intensity with a footswitch, and a 12AX7 phase inverter drives a pair of 6L6s on a diode bridge rectifier with a standby switch, into two 12-inch speakers. Four 12AX7s in all.

Tags: american, vintage, 6l6, tremolo, 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.