Mesa Boogie Bass 400+ Head - USA 1993

Here is a Mesa Boogie Bass 400+, a legendary all-tube bass amplifier head that has been a staple among professional bass players since its introduction in the late 1970s. Renowned for its immense power, headroom, and rich harmonic character, the Bass 400+ delivers the kind of warm, authoritative tone that defines classic tube bass amplification.

At the heart of the amp is a highly flexible EQ section, featuring a 4-band layout with controls for bass, low mid, high mid, and treble. This allows for precise tonal shaping across the full frequency spectrum. A dedicated Deep switch enhances low-end response for added punch and weight, while the Bright switch introduces extra clarity and definition in the top end.

Beyond its core tone-shaping capabilities, the Bass 400+ includes a range of practical features for both stage and studio use. A built-in limiter helps control peaks and protect speakers under high output conditions, while the balanced XLR output allows for direct connection to recording setups or live mixing consoles. A series effects loop is also included, making it easy to integrate pedals and external processing into your signal chain.

This example presents in great working condition and is fully functional. It shows some cosmetic wear consistent with regular gigging over the years, including minor paint loss, but remains in excellent shape for its age. The amp was re-tubed in the early 2000s and has been reliably used in live settings up until recent years.

Specifications:

Year: 1993
Country: USA (Petaluma, California)
Model: Mesa Boogie (500W all-tube bass head, exact model not specified)
Power: 500 watts @ 2 ohms (Class A/B)
Power Tubes: 12 × 6L6
Preamp Tubes: 4 × 12AX7
Channels: 2 inputs (Active / Passive with independent pull-bright volumes)
Controls: Volume (pull bright), bass (pull shift), mid, treble (pull shift), 7-band graphic EQ (assignable), FX loop blend, slave level
Inputs: 2 (Active and Passive)
Outputs: 600 Ohm XLR balanced out
Effects Loop: Dual patch point FX loop (front & rear) with blend control
Cooling: 3-speed fan (Off, Low, High)
Bias: Fixed bias
Construction: All-tube bass amplifier head
Dimensions: 10.375" × 18.75" × 12.5"
Accessories: Roadcase with wheels included