Selmer Zodiac Twin 50 - Selectortone preset

Verified · 84/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Selmer Zodiac Twin 50 is a two-channel valve combo. Channel 1 has an ECC83 input, a tone control and its own volume into an EF86 pentode; channel 2 has an ECC83 input into Selmer’s push-button tone selector and its own volume into a second EF86. An ECC83 tremolo with speed and depth also drives an EM84 magic eye. An ECC83 gain stage and splitter drive two fixed-bias EL34s, with a GZ34 rectifier at about 470 V and an IS105 bias diode.

• Made in: UK
• Wattage: 50W
• Channels: 2
• Preamp tubes: 3× ECC83, 2× EF86
• Power tubes: 2× EL34

Tags: british, vintage, two-channel, 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.