What tubes does the Mesa Boogie Bass 400+ - Channel 2 use?

The Mesa Boogie Bass 400+ - Channel 2 uses 4× 12AX7 preamp tubes and 12× 5881 power tubes.

When was the Mesa Boogie Bass 400+ - Channel 2 produced?

The Mesa Boogie Bass 400+ - Channel 2 was produced 1989–2009.

Mesa Boogie Bass 400+ - Channel 2 preset

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

The Bass 400+ is Mesa/Boogie's reworked Bass 400, built from 1989 to 2009. Two inputs, one active and one passive, each have a volume with pull bright and feed a shared tone stack with pull shift on bass and treble, an assignable graphic EQ (six bands at first, seven from 1990) and a blendable effects loop. Twelve 6L6s deliver about 500 watts into 2 ohms of punchy, harmonically rich low end, with XLR and slave outputs.

Years produced: 1989–2009
Made in: USA
Wattage: 500W
Channels: 2
Preamp tubes: 4× 12AX7
Power tubes: 12× 5881

Tags: american, bass, all-tube, high-power, graphic-eq, 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.