Red Bear Cub Combo MkX50 preset

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

The Red Bear Cub Combo MkX50 is a single-channel tube combo from Gibson’s mid-1990s Red Bear line, built around Russian valves. Four 6N2P-EV dual triodes, a 12AX7-type equivalent, handle the preamp, with a footswitch that bypasses or adds a gain stage, a Gain control, and treble, bass and mid with Master and Presence. A switchable-level effects loop (+4/−7/−20 dB) feeds a long-tail inverter and two fixed-bias 5881s. There is no reverb.

• Made in: Russia
• Wattage: 50W
• Channels: 1
• Preamp tubes: 4× 6N2P-EV
• Power tubes: 2× 5881

Tags: reverb, 6l6, mid-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.