Sunn Sonic II / 1-40 / 200S / Sorado preset

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

One 1969 Sunn schematic covers the Sonic II, Sonic 1-40, 200S and Sorado, which share a circuit in different cabinet configurations. Two inputs feed a 12AX7 with a Lo Boost switch and Volume, then passive Treble and Bass controls with a Hi Boost switch. A 6AN8 pentode gain stage and triode cathodyne inverter, with feedback from the output, drive two 6550s in adjustable fixed bias from a GZ34 rectifier with choke and standby. Sunn's notes list the Sonic II as discontinued in 1968.

• Made in: USA
• Wattage: 60W
• Channels: 1
• Preamp tubes: 1× 12AX7, 1× 6AN8
• Power tubes: 2× 6550

Tags: american, vintage, 6550, 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.