What tubes does the Hiwatt Sta 250 250R 100 Pre use?

The Hiwatt Sta 250 250R 100 Pre uses 4× ECC83 preamp tubes.

When was the Hiwatt Sta 250 250R 100 Pre produced?

The Hiwatt Sta 250 250R 100 Pre was produced 1970s–1980s.

Hiwatt Sta 250 250R 100 Pre preset

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

Preamp schematic for the Hiwatt STA250 and STA250R studio monitor amplifiers. The 100W preamp section documents the ECC83 input and gain stages for these high-powered studio units.

Years produced: 1970s–1980s
Made in: UK
Channels: 1
Preamp tubes: 4× ECC83

Tags: british, clean, studio, sub-circuit.

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.