Ampeg M-12A (7591A version) - Accordion preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The M-12A with 7591A output tubes is an updated version of the M-12 accordion amplifier. The 7591A tubes provide more power and slightly different tonal characteristics than the 6V6 version. The Accordion channel is voiced for clean, clear reproduction of the instrument's complex harmonic content.

• Years produced: 1962–1966
• Made in: USA
• Wattage: 15W
• 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.