Univox U-320APB - Reverb preset

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

The U-320APB is a Japanese-built Univox valve combo of the late 1960s. Two channels, each with Bright and Normal inputs, a 12AX7 stage, its own volume and its own tone control, mix into a 12AX7 gain stage and cathodyne inverter driving two fixed-bias 7591s with negative feedback. A 6AN8 drives the spring reverb with a 12AX7 recovery stage, level control and footswitch, and a 12AX7 tremolo works through a 12AU7 that modulates the output bias.

• Made in: Japan
• Channels: 2
• Preamp tubes: 3× 12AX7, 1× 12AU7, 1× 6AN8
• Power tubes: 2× 7591

Tags: japanese, vintage, reverb, tremolo, 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.