Kay 803 preset

verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Kay 803 is a small early-1960s practice amp using a 12AU6 preamp pentode, a single-ended 50L6 output tube and a 35Z5 rectifier, with an isolation transformer and an 8-inch speaker. It has volume and tone and produces only a couple of watts, breaking up quickly.

• Made in: USA
• Wattage: 2W
• Channels: 1
• Preamp tubes: 1× 12AU6
• Power tubes: 1× 50L6

Tags: american, vintage, practice, low-wattage, breakup.

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.