Ampeg SVT (1969-71) - Channel 1 preset

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

The original 1969-71 SVT with 6146B output tubes is the first iteration of the world's most iconic bass amplifier. Channel 1 feeds the high-gain preamp directly into the six-tube 300-watt output section. The early 6146B-equipped SVT is considered by many collectors and players to be the most tonally distinctive version, with a harder, more aggressive character.

• Years produced: 1969–1971
• Made in: USA
• Wattage: 300W
• Channels: 2
• Preamp tubes: 6× 12AX7, 2× 12AU7
• Power tubes: 6× 6146B

Known for: Paul McCartney, Geddy Lee, John Entwistle, Lemmy Kilmister, Geezer Butler, Cliff Burton.

Heard on: Won't Get Fooled Again — The Who (1971); Whole Lotta Love — Led Zeppelin (1969).

Tags: bass, american, vintage, high-wattage, clean.

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.