Ampeg 835 preset

Verified · 82/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Ampeg 835-N is a late-1950s tube combo built in Woodside, New York. Three inputs feed a 6CG7 whose two halves form the gain stages around a passive Bass and Treble network and a Volume control, followed by a 6SL7 paraphase phase inverter. A push-pull pair of cathode-biased EL37 output pentodes drives the speaker and an extension jack, with negative feedback, a 5U4 rectifier and an OC3 regulator in the supply.

• Made in: USA
• Wattage: 35W
• Channels: 1
• Preamp tubes: 1× 6CG7, 1× 6SL7
• Power tubes: 2× EL37

Tags: american, vintage, bass, mid-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.