Valco PA Model 1200 - Microphone preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

A Valco-built public-address amplifier sold under the National name, not a dedicated guitar amp. A 6SJ7 mic preamp and two instrument inputs feed a 6SL7 and a 6SN7 inverter into a pair of 6L6s, with a 5Y3GT rectifier and a field-coil speaker. Its mic and instrument inputs each have their own volume.

• Made in: USA
• Channels: 2
• Preamp tubes: 1× 6SJ7, 1× 6SL7, 1× 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.