Airline GDR-8512A / GDR-8502A preset

Verified · 92/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Airline GDR-8512A is a small single-ended Montgomery Ward instrument amp sharing its circuit with the GDR-8502A. A 6AU6 pentode preamp drives a single 6V6GT for about 5 watts, with a 6X5GT rectifier and volume and tone controls.

• Made in: USA
• Wattage: 5W
• Channels: 1
• Preamp tubes: 1× 6AU6
• Power tubes: 1× 6V6GT

Tags: american, vintage, 6v6, class-a, low-wattage.

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.