The Phil Jones Bass D-400 is a professional-grade, high-fidelity bass amplifier head designed for musicians who refuse to compromise on tone, power, or portability.
Fanless Efficiency & Premium Engineering
Delivering a 350 Watts RMS, this compact head wraps clean acoustic reproduction into a lightweight package.
It is a great tool for studio tracking, theatre pits, and live stages where absolute transparency and absolute silence from your electronic gear are required.
The defining feature of the D-400 is its completely noise-free operation.
Utilising advanced, high-efficiency Class D amplifier circuitry, the head generates minimal heat, entirely eliminating the need for an internal cooling fan.
This ensures the amplifier runs completely silent and cool, enhancing long-term reliability while removing background fan hum during critical microphone recordings.
The chassis itself is a testament to premium engineering, precision-machined from aircraft-grade anodised black aluminium and built to a standard 1U height for seamless rack-mounting integration.
Creative Tone Shaping & Dynamics Control
For precise acoustic control, the D-400 features a highly responsive 5-band graphic equaliser, allowing you to tailor your sound to any room or cabinet configuration.
The input stage is equipped with a three-way mini switch to toggle between Mute, Low, and High sensitivity modes, safely accommodating both passive and hot active instruments.
To keep your dynamics perfectly balanced, the front panel includes a switchable Compressor & Limiter, which smooths out transient peaks and adds natural sustain without colouring your fundamental instrument tone.
Phil Jones Bass D-400 Bass Samp Head Features & Specifications
High-efficiency Class D amplifier design provides clean, uncoloured power
Fanless cooling system guarantees completely silent, noise-free operation
Precision-crafted chassis made from rugged, aircraft-grade anodised black aluminium
Standard 1U form factor for optional rack-mount configuration
Power output: 350 Watts RMS into 4 Ohms, 200 Watts RMS into 8 Ohms
Precise 5-band graphic EQ for advanced, musical tone shaping
Input sensitivity toggle switch (Mute / Low / High) to match active or passive basses
Built-in studio-quality Compressor & Limiter with dedicated on/off switch
Balanced XLR DI-Out for direct routing to front-of-house or recording interfaces
Dedicated PreAmp-Out and independent Headphone-Out for versatile routing options
Global voltage compatibility: 100 – 240V AC for international touring flexibility
Dimensions: 244mm x 193mm x 43mm (9.6" x 7.6" x 1.7")
Ultra-lightweight design weighing only 1.3 kg (2.9 lbs)
Professional matte black finish with premium tactile control knobs
Compatible with an optional PJB padded soft gig bag (sold separately)