Ampeg SVT-2PRO preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Ampeg SVT-2PRO is a 300-watt all-tube rack bass head. A -15 dB pad and gain control feed 12AX7 stages with Bright, Ultra Low and Ultra High switches, a drive control, bass and treble, and a mid control with a five-position frequency switch on an inductor, then a graphic EQ loop and master. In the power amp a 12AX7 phase inverter and two 12AU7 drivers with separate bias controls run six 6550s, with bias indicator LEDs, effects loop, slave out and XLR DI.

• Made in: USA
• Wattage: 300W
• Channels: 1
• Preamp tubes: 5× 12AX7, 3× 12AU7
• Power tubes: 6× 6550

Known for: Tim Commerford, Mike Inez, Robert Trujillo, Robert Levon Been, Eva Gardner, Hutch Hutchinson, Taras Prodaniuk, Jason Newsted, Brad Stewart, Randy Bradbury.

Heard on: Little Thing Gone Wild — Black Rebel Motorcycle Club (2018).

Tags: american, bass, 6550, high-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.