Marshall 5520 Bass Combo - Channel B preset

Verified · 84/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Model 5520 is a solid-state Marshall bass combo from 1982. A single input feeds a 2N3819 FET stage and a switchable compressor with Threshold and Volume, then splits into two footswitchable channels with indicator LEDs. Channel A has Sensitivity, Contour and a multi-band active EQ with diode-limited Volume; Channel B has its own Volume and EQ. CA1458 op-amps handle all the preamp and EQ stages.

• Made in: UK
• Wattage: 200W
• Channels: 2

Tags: british, solid-state, bass, two-channel, high-wattage.

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.