Carlsbro 100 PA Reverb preset

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

The Carlsbro 100 PA/R is a 100-watt valve PA head with reverb. Four inputs, each with its own 500K level control, are mixed in pairs onto the two halves of an ECC83, then a second ECC83 stage feeds bass, middle and presence controls, a further gain stage and master volume. A transistor-driven spring reverb with level and footswitch is mixed back in, and a long-tail phase inverter drives four fixed-bias EL34s with 3.75, 7.5 and 15 ohm taps.

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

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

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.