HH Scott 99-D preset

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

The 99-D is a mono integrated amplifier from H.H. Scott. Three 12AX7s handle phono preamp, tone, loudness and the phase inverter with a balance control. Two 6L6GB output tubes on a 5U4GA rectifier make about 20 watts. It is a compact 6L6 hi-fi amp that is often repurposed for clean guitar or harmonica.

• Made in: USA
• Wattage: 20W
• Channels: 1
• Preamp tubes: 3× 12AX7
• Power tubes: 2× 6L6GB

Tags: american, vintage, 6l6, 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.