What tubes does the Hiwatt Sta 400 Slave use?

The Hiwatt Sta 400 Slave uses 1× ECC83 preamp tubes and 16× EL34 power tubes.

When was the Hiwatt Sta 400 Slave produced?

The Hiwatt Sta 400 Slave was produced 1970s.

Hiwatt Sta 400 Slave preset

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

The Hiwatt STA400 slave is a 400-watt pure power amplifier from the Hiwatt studio monitor series. Sixteen EL34 output tubes deliver massive clean headroom for studio and large venue monitoring applications.

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

Tags: british, clean, studio, 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.