Masco MU-17 - Mic preset

Verified · 89/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The MU-17 (Sams 1952) is a combined instrument and microphone amplifier. A 12AX7 gives Instrument inputs 1-2 and Instrument 3 a triode and volume control each, and a 6J7 pentode serves the mic input with its own volume. They share a single tone control and a 12AX7 gain and paraphase stage driving two cathode-biased 6L6s in push-pull from a 5Y3GT. Masco (Mark Simpson Manufacturing Co.) built PA and instrument amplifiers in New York.

• Made in: USA
• Wattage: 17W
• Channels: 2
• Preamp tubes: 2× 12AX7, 1× 6J7
• Power tubes: 2× 6L6G

Tags: american, vintage, 6l6, low-wattage, two-channel.

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.