Kay K-750 preset

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

The Kay K-750 is a small late-1960s amp using series-string tubes: an 18GD6A preamp, a single-ended 60FX5 output pentode and a 36AM3 rectifier, making a few watts into an 8-inch Oxford speaker. It has three inputs, volume and tone. It is a simple, raw practice amp that breaks up quickly.

• Made in: USA
• Wattage: 4W
• Channels: 1
• Preamp tubes: 1× 18GD6A
• Power tubes: 1× 60FX5

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.