Mesa Boogie Studio Preamp - Rhythm preset

Close · 77/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The Studio Preamp is Mesa/Boogie's all-valve rack preamp, with Rhythm and Lead channels and five 12AX7s. It uses a Mark-style tone stack with LDR switching, a cascaded lead path, a transistor-buffered 5-band graphic EQ, valve-driven reverb and effects loops.

• Introduced: 1988
• Made in: USA
• Channels: 2
• Preamp tubes: 5× 12AX7

Known for: Kurt Cobain.

Heard on: Smells Like Teen Spirit — Nirvana (1991).

Tags: american, preamp, high-gain, reverb, two-channel.

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.