Hiwatt DR103 Custom 100 preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The DR103 Custom 100 is the 100-watt head Dave Reeves built under the Hiwatt name from 1969. Normal and Brilliant channels, each with high and low inputs, share Hiwatt's own Treble/Middle/Bass stack, Presence and Master Volume. A cathode follower drives a long-tailed pair and four EL34s on a stiff silicon supply and Partridge iron. Huge clean headroom and clear note separation made it the backbone of Pink Floyd's 1970s sound.

• Years produced: 1969–present
• Made in: UK
• Wattage: 100W
• Channels: 2
• Preamp tubes: 4× ECC83
• Power tubes: 4× EL34

Known for: David Gilmour, Roger Waters.

Heard on: Money — Pink Floyd (1973); Dogs — Pink Floyd (1977).

Tags: british, vintage, clean, el34, high-wattage, hand-wired, 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.