Valco National Dobro B preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The National Dobro Model B was an early production amplifier from the National Dobro company, one of the first generation of instruments designed for electric steel guitar amplification. Its primitive circuit reflected the infant state of amplifier technology in the mid-1930s, using directly heated triodes or early pentodes as output valves. These Model B amps are important historical artifacts of the earliest days of electric guitar amplification in America.

• Years produced: 1934–1938
• Made in: USA
• Channels: 1

Tags: american.

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.