Sho-Bud Compactra 100 preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Compactra-100 is Sho-Bud's tube steel-guitar amplifier, designed by Evans Electronics and built 1965–1969. Two inputs each get their own 7025 gain stages with Volume and Body controls, then a shared bass/treble stack, Hammond spring reverb driven by a 6CS7, and a 7199 phase inverter with AC balance trim. Two 7027A beam tetrodes run push-pull from a silicon-rectified supply, with a 6L6GC used as a series regulator for the screen supply.

• Made in: USA
• Wattage: 100W
• Channels: 1
• Preamp tubes: 3× 7025, 1× 7199, 1× 6CS7
• Power tubes: 2× 7027A

Tags: american.

Schematic-derived preset files for 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.