HH Scott 250 preset

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

The Type 250 Laboratory Power Amplifier is a mono tube hi-fi power amp from H.H. Scott. Two 12AX7s serve as input, driver and inverter. A push-pull pair of 6CA7 (EL34) output tubes has adjustable bias plus AC and DC balance controls, on a 5U4 rectifier with a separate diode bias supply. It delivers around 40 watts of clean EL34 power.

• Made in: USA
• Wattage: 40W
• Channels: 1
• Preamp tubes: 2× 12AX7
• Power tubes: 2× 6CA7

Tags: american, vintage, power-amp, el34, clean, 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.