What tubes does the Fender 400PS - Normal use?

The Fender 400PS - Normal uses 3× 7025, 2× 12AX7, 1× 12AT7, 1× 6L6GC preamp tubes and 6× 6550 power tubes.

When was the Fender 400PS - Normal produced?

The Fender 400PS - Normal was produced 1970–1975.

Fender 400PS - Normal preset

Verified · 87/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The 400PS is Fender's most powerful tube bass amp of the CBS era. It has a Bass Instrument channel with treble, bass, volume and a deep switch, and a Normal channel with treble, middle, bass, volume and a bright switch, plus vibrato with speed and intensity and spring reverb, both with pedal switches. A master volume feeds a 6L6GC driver into a driver transformer, which drives six selected 6550s in push-pull. Three speaker jacks are each rated 145 W into 4 ohms.

Years produced: 1970–1975
Made in: USA
Wattage: 400W
Channels: 2
Preamp tubes: 3× 7025, 2× 12AX7, 1× 12AT7, 1× 6L6GC
Power tubes: 6× 6550

Tags: american, vintage, bass, 6550, high-wattage, clean, 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.