Hiwatt Custom 400 DR405 - Normal preset

Verified · 85/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The DR405 Custom 400 is the biggest head in Hiwatt's Custom range. Normal and Brilliant channels with their own volumes feed a cascaded ECC83 stage, a treble, middle and bass stack and a master. An ECC81 long-tailed pair with presence and feedback drives ECC83 cathode followers and six KT88s into a Partridge output transformer, on twin bridge rectifiers with a choke. It was built mainly for bass on very large stages.

• Made in: UK
• Wattage: 400W
• Channels: 2
• Power tubes: 6× KT88

Tags: british, vintage, high-wattage, two-channel.

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.