Teisco Checkmate 20 preset

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

The Teisco Checkmate 20 is a 1960s Japanese combo with reverb and tremolo. Three inputs feed a 12AX7 stage, passive treble and bass controls, a volume and a second 12AX7 stage. A 12AU7 handles phase inversion with negative feedback from the speaker, driving two cathode-biased 7189A (EL84-family) pentodes. Another 12AX7 drives the spring reverb, a 6AV6 runs the tremolo with a depth control, and a solid-state doubler rectifies.

• Made in: Japan
• Wattage: 20W
• Channels: 1
• Preamp tubes: 2× 12AX7, 1× 12AU7, 1× 6AV6
• Power tubes: 2× 7189A

Tags: japanese, 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.