Hiwatt Hwslave400W preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Hiwatt 400-watt slave amplifier is an extremely high-powered pure power amp stage using sixteen EL34 output tubes. Intended for arena-scale concert use as a slave driven from a Hiwatt DR preamp.

• Years produced: 1970s
• Made in: UK
• Wattage: 400W
• Channels: 1
• Preamp tubes: 1× ECC83
• Power tubes: 16× EL34

Known for: Pete Townshend.

Tags: british, clean, vintage, slave-amp, high-wattage.

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.