Impact PA 100 preset

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

The PA 100 was a 100-watt professional microphone amplifier from Impact, made by Pan Musical Instrument Co in London in 1968. It has four identical ECC83 channels, each with bass, treble and volume, then a master volume, a limiter switch and an ECC83 phase inverter. The inverter drives four EL34s on a silicon bridge rectifier. It is a different product from the three-channel Impact 100 guitar head, but shares the same British EL34 power section.

• Made in: UK
• Wattage: 100W
• Channels: 1
• Preamp tubes: 5× ECC83
• Power tubes: 4× EL34

Tags: british, vintage, el34, high-wattage.

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.