What tubes does the Ampeg M-15 (The Big M) - Instrument use?

The Ampeg M-15 (The Big M) - Instrument uses 3× 12AX7 preamp tubes and 2× 6L6 power tubes.

When was the Ampeg M-15 (The Big M) - Instrument produced?

The Ampeg M-15 (The Big M) - Instrument was produced 1963–1968.

Ampeg M-15 (The Big M) - Instrument preset

Close · 75/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The M-15 'The Big M' is a large-format accordion and instrument amplifier with a 15-inch speaker. The Instrument channel provides clean, warm amplification for accordion and keyboard instruments. The Big M nickname refers to the substantial cabinet size housing the 15-inch driver, offering fuller low-frequency response than the smaller M-12.

Years produced: 1963–1968
Made in: USA
Wattage: 25W
Channels: 2
Preamp tubes: 3× 12AX7
Power tubes: 2× 6L6

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.