Rob Robinette RobRob Stereo preset

Verified · 93/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The RobRob Stereo Amplifier is Rob Robinette’s two-sided single-ended design on one shared power supply. Each side has its own input into a 12AX7 preamp triode, a 1M volume, and the second triode as driver, feeding one cathode-biased octal power pentode into a Hammond 125CSE output transformer, with 22K negative feedback from the speaker. There is no tone stack. A silicon bridge rectifier, 30H choke and hum-balance pot complete the supply.

• Made in: USA
• Channels: 1
• Preamp tubes: 2× 12AX7

Tags: american, diy, stereo, class-a, low-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.