Univox U-1075 - Channel 4 preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The U-1075 is a Univox valve PA-style head of the early 1970s, not a solid-state amp. Four channels, each with high and low inputs, a 12AX7 triode stage and its own volume, mix into a 12AU7 stage feeding shared treble, middle and bass controls, a second 12AU7 stage and a master volume. A 12AX7 long-tail inverter with presence and negative feedback drives four fixed-bias 6L6GCs at about 470 V, with a choke-filtered silicon supply and an impedance selector.

Tags: japanese, 6l6, high-wattage, multi-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.