Kay 77 preset

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

The Kay Model 77 is a 1948 practice amp in a small portable cabinet. Two inputs feed a 6SL7GT twin triode used as two cascaded gain stages, then a single-ended, cathode-biased 6V6GT drives the speaker through a small output transformer. A 5Y3GT rectifier with a filter choke powers it. There is no tone circuitry to speak of, so it gives a simple, warm, low-powered tone that breaks up readily when turned up.

• Made in: USA
• Wattage: 4W
• Channels: 1
• Preamp tubes: 1× 6SL7GT
• Power tubes: 1× 6V6GT

Tags: american, vintage, 6v6, class-a, low-wattage, practice.

Schematic-derived preset files for 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.