What tubes does the Valco National-Dobro Model 75 - Normal use?

The Valco National-Dobro Model 75 - Normal uses 1× 12AX7 preamp tubes and 1× 6V6 power tubes.

When was the Valco National-Dobro Model 75 - Normal produced?

The Valco National-Dobro Model 75 - Normal was produced 1940s.

Valco National-Dobro Model 75 - Normal preset

Verified · 83/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The National-Dobro Model 75 is a small amplifier from the earliest period of Valco's production history, built for the lap steel guitar market before the company fully established the Supro and National brand identities. The simple single-ended design produces a warm, lo-fi character that has made early National-Dobro amps appealing to players seeking authentic 1940s American tone. This schematic documents a historically significant early Valco product.

Years produced: 1940s
Made in: USA
Wattage: 5W
Channels: 1
Preamp tubes: 1× 12AX7
Power tubes: 1× 6V6

Tags: american, vintage.

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.