Magnatone M-199-3-J preset

Close · 60/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The M-199-3-J is an early Magna Electronics (Magnatone) amp from around 1952, likely sold with a lap-steel outfit. Two inputs feed a 6SJ7 pentode preamp, then a single Volume control drives a cathode-biased, single-ended beam output valve into a small speaker, with a 5Y3 rectifier and a simple two-stage filter supply. There is no tone control, so it gives a plain, warm clean that compresses and breaks up early.

• Made in: USA
• Wattage: 5W
• Channels: 1
• Preamp tubes: 1× 6SJ7
• Power tubes: 1× 6V6

Tags: american, vintage, 6v6, class-a, low-wattage, clean.

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.