Valco 510-4 - Microphone preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The 510-4 is Valco's 1947 chassis with a microphone channel and an instrument channel. Each has its own 6SJ7 pentode input stage and its own volume control; the two mix into a 6SN7 gain stage and a tone control, then a second 6SN7 phase inverter. A push-pull pair of 6L6s drives a field-coil speaker, with a 5Y3GT rectifier for the HT and a separate selenium rectifier powering the speaker field.

• Made in: USA
• Wattage: 20W
• Channels: 2
• Preamp tubes: 2× 6SJ7, 2× 6SN7
• Power tubes: 2× 6L6

Tags: american, vintage, 6l6, 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.