Supro Early 1953 preset

Verified · 84/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

An early-1953 Valco-built Supro, a single-ended practice combo. Two inputs feed one half of a 6SL7GT, then a 500K volume control and the second 6SL7 half, followed by a simple treble-cut tone control. A single 6V6GT runs cathode-biased in class A with an unbypassed 330-ohm cathode resistor and no negative feedback, into a 10-inch 3.2-ohm speaker, with a 5Y3GT rectifier.

• Made in: USA
• Wattage: 5W
• Channels: 1
• Preamp tubes: 1× 6SL7GT
• Power tubes: 1× 6V6GT

Tags: american, vintage, 6v6.

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.