Carlsbro CS100B - Normal preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The CS100B is a 100-watt Carlsbro valve bass head. Two pairs of inputs, each with its own volume, are mixed and amplified by a twin-triode front end, then pass through a tone network with a wide-range 2M bass control, middle and treble, and a further gain stage with volume and presence. A twin-triode long-tail phase inverter drives four output pentodes with fixed bias, fed from a silicon bridge rectifier on a 350 V winding.

• Made in: UK
• Wattage: 100W
• Channels: 2
• Power tubes: 4× EL34

Tags: british, vintage, bass, 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.