Silvertone 1303 preset

verified · 89/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Silvertone 1303 is an early Sears combo with three inputs feeding a single channel with Volume, Treble and Bass on an upper control panel. A 12SJ7 pentode and a 12SN7 dual triode (gain plus phase inverter) drive two 6L6G output valves push-pull, with a 7C7 tremolo oscillator (Rate control and on/off switch), a 5U4 rectifier and a field-coil speaker whose field doubles as the supply choke.

• Made in: USA
• Wattage: 20W
• Channels: 1
• Preamp tubes: 1× 12SJ7, 1× 12SN7, 1× 7C7
• Power tubes: 2× 6L6G

Tags: american, vintage.

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.