Marshall AVT150 / AVT275 - OD1 preset

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

The AVT150 (combo and head) and AVT275 (stereo combo) are the largest models from Marshall's AVT (Advanced Valvestate Technology) range. An op-amp preamp feeds a single ECC83 valve stage and a solid-state power amp. Both have three channels (Clean, OD1 and OD2), digital effects and an effects loop; the AVT275 uses two power amps for stereo.

• Made in: UK
• Wattage: 150W
• Channels: 3
• Preamp tubes: 1× ECC83

Tags: british, hybrid, crunch, high-gain, high-wattage, multi-channel, stereo.

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.