What tubes does the Marshall Major 1966 200W PA - Normal use?

The Marshall Major 1966 200W PA - Normal uses 3× ECC83 (12AX7) preamp tubes and 4× KT88 power tubes.

When was the Marshall Major 1966 200W PA - Normal produced?

The Marshall Major 1966 200W PA - Normal was produced 1966–1975.

Marshall Major 1966 200W PA - Normal preset

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

The Marshall Major 200W PA (1966 version) is one of the earliest and rarest of Marshall's 200W line, configured as a public address amplifier with four input channels and the massive KT88-powered output stage that defined the Major range. With 200 watts on tap — double any other Marshall head of the era — it was designed for large venues and outdoor stages where extreme volume was the primary requirement. Its KT88 output valves give it a harder, more powerful character than the EL34-based heads, with enormous headroom and substantial low-end authority.

Years produced: 1966–1975
Made in: UK
Wattage: 200W
Channels: 4
Preamp tubes: 3× ECC83 (12AX7)
Power tubes: 4× KT88

Tags: british, crunch.

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.