Guild Thunderbird / Superbird - Normal preset

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

Guild's late-1960s Thunderbird and Superbird I/II share this preamp. A Normal channel and a Tremolo-Reverb-Fuzz channel, two inputs each, have their own treble, bass and volume with voicing switches. A 6GW8 drives the spring reverb, and a 12AX7 tremolo has depth, speed, a two-speed range switch, both footswitchable. A diode fuzz on the second channel (replaced by a capacitor in the Thunderbird) and a master volume feed the separate power amp.

Tags: american, vintage, reverb, tremolo, two-channel.

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.