Univox U-50 preset

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

The U-50 is a 50-watt RMS Univox PA amplifier from 1972, built by Unicord. It is a hybrid, not a solid-state amp: four input channels, each with a FET input stage, treble, bass and its own volume, plus a per-channel reverb send switch, feed a transistor mixer, a transistor-driven spring reverb and a master volume. A 12AX7 long-tail inverter then drives two fixed-bias 6L6GCs from a silicon supply into 4- or 8-ohm outputs.

• Made in: Japan
• Wattage: 50W
• Channels: 1
• Preamp tubes: 1× 12AX7
• Power tubes: 2× 6L6GC

Tags: japanese, hybrid, 6l6, mid-wattage.

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.