SJB ANT Reverb Head preset

Verified · 85/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The SJB ANT is a single-channel valve reverb head. An EF83 pentode input stage feeds a passive treble/bass/mid tone stack and Volume, then two 12AU7 (or 12AX7) gain stages and a Master. A 6U8A drives and recovers an Accutronics spring tank with a Reverb level control. A 12AT7 long-tail phase inverter drives four 6V6GTs push-pull, cathode-biased in pairs, with negative feedback from the output; the supply uses silicon diodes and runs about 390 V.

• Wattage: 40W
• Channels: 1
• Preamp tubes: 1× EF83, 1× 12AU7, 1× 6U8A, 1× 12AT7
• Power tubes: 4× 6V6GT

Tags: reverb.

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.