AX84 High Octane preset

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

The High Octane is one of the AX84 community's free DIY amp designs: a small single-ended amp for high-gain tones at low volume. Two 12AX7s give three cascaded gain stages with Gain 1 and Gain 2 controls and a cathode follower driving a treble, bass and mid tone stack, then a master volume. The output stage has parallel EL84 and 6V6 sockets, only one valve fitted at a time, cathode biased into a single-ended transformer with 4, 8 and 16 ohm jacks.

• Wattage: 5W
• Channels: 1
• Preamp tubes: 2× 12AX7
• Power tubes: 1× EL84 or 6V6

Tags: diy, el84, high-gain, low-wattage, class-a.

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.