What tubes does the Ampeg M-18 - Instrument use?

The Ampeg M-18 - Instrument uses 3× 12AX7 preamp tubes and 2× 7591A power tubes.

When was the Ampeg M-18 - Instrument produced?

The Ampeg M-18 - Instrument was produced 1963–1967.

Ampeg M-18 - Instrument preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The M-18 is an accordion and instrument amplifier using 7591A output tubes. The Instrument channel provides clean, full-range amplification suited to accordion, organ, and other keyboard instruments. A mid-power option in Ampeg's M-series instrument amplifier lineup.

Years produced: 1963–1967
Made in: USA
Wattage: 18W
Channels: 2
Preamp tubes: 3× 12AX7
Power tubes: 2× 7591A

Tags: american, vintage, low-wattage, clean, accordion.

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.