Guild Thunderstar Bass preset

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

The Thunderstar Bass is a single-channel Guild tube bass head drawn in 1968. Two inputs feed half of a 12AX7 with bass, treble, volume and a tone switch. A 7247 handles the driver and inverter, and two 6L6GC output tubes have individual bias controls on a diode-rectified supply. It is simpler than Guild's two-channel Thunderbass and built for clean, firm low end.

• Made in: USA
• Wattage: 50W
• Channels: 1
• Preamp tubes: 1× 12AX7, 1× 7247
• Power tubes: 2× 6L6GC

Tags: american, vintage, bass, 6l6, mid-wattage.

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.