What tubes does the Sunn 1200S use?

The Sunn 1200S uses 1× 12AX7, 1× 12AU7, 1× 6AN8 preamp tubes and 4× 6550 power tubes.

Who famously used the Sunn 1200S?

Greg Anderson, and Stephen O'Malley are among the notable players associated with the Sunn 1200S.

Sunn 1200S preset

Close · 78/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The Sunn 1200S (1971 schematic) is a high-powered head sold with a cabinet of six 12-inch speakers (JBL D123F optional). Normal and Bright inputs plus switching input jacks feed a 12AX7 with Volume, Treble, Bass, Contour and a midrange boost switch, with a 12AU7-driven spring reverb and transistor recovery and a photocell tremolo with a transistor oscillator, Depth and footswitch. A 6AN8 gain stage and inverter drives four 6550s in fixed bias, from a silicon-diode supply with chokes and standby.

Made in: USA
Wattage: 120W
Channels: 1
Preamp tubes: 1× 12AX7, 1× 12AU7, 1× 6AN8
Power tubes: 4× 6550

Known for: Greg Anderson, Stephen O'Malley.

Tags: american, vintage, 6550, reverb, tremolo, 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.