Ashdown ABM-600-Evo IV, 600w Bass Head

Ashdown ABM-600-EVO IV – 600W Bass Amplifier Head

The Ashdown ABM-600-EVO IV bass head is the latest evolution of Ashdown’s flagship ABM series. Trusted by professional bassists worldwide for over two decades, the ABM range delivers unrivalled tone, power, and flexibility. With 600 watts of stage-ready output, the EVO IV takes performance to the next level.

Variable Valve Drive Plus – From Clean to Overdrive

At the heart of the ABM-600-EVO IV is the upgraded Variable Valve Drive Plus preamp. Delivering more current to the 12AX7 tube, it produces a wider range of harmonics and more drive than ever before. Dial in everything from pristine clean bass tones to fat, roaring overdrive, and switch it instantly via footswitch.

Precision 9-Band EQ

The new 9-band EQ combines familiar bass, mid, and treble controls with six additional sliders (100Hz, 180Hz, 340Hz, 1.3kHz, 2.6kHz, 5kHz) for surgical tone shaping. With a flick of a switch (or footswitch), you can shift from a flat fretless tone to a fully sculpted live sound in an instant.

Classic ABM Features Retained

• One-Knob Dynamic Compressor: Smooth, even tone with a single control.

• Sub-Harmonic Generator: Adds an octave below your notes for rich, full bass sound.

Professional Connectivity

• Speaker Outputs: 2 x Neutrik Jack/SpeakON (minimum 4Ω load)

• Inputs/Outputs: High & Low Instrument Inputs, Line Input, DI Output, Tuner Out, Transparent FX Loop

• Silent Tuning: DI muting leaves the tuner output live for onstage tuning.

Flexible Footswitching (FS-4 Compatible)

When paired with the Ashdown FS-4 footswitch (sold separately), you can control Valve Drive, Compression, EQ, and Sub-Harmonic Generator on the fly – unlocking dozens of tonal options without the need for extra pedals.

Specifications

• Power Output: 600 Watts

• Power Requirement: 115–230V

• Speaker Outputs: 2 x Jack/SpeakON (min. 4Ω load)

• Frequency Response: -3dB @ 17Hz – 30kHz

• Inputs: High (3.9MΩ), Low (22kΩ)

• Line Input: 22kΩ, 0dBu nominal

• DI Output: 600Ω balanced, 0dBu nominal

• Tuner Output: 22kΩ, 0dBu nominal

• FX Send/Return: 22kΩ, 0dBu nominal

• Dimensions (H x W x D): 146 x 489 x 336 mm

• Weight: 12.5 kg

Why Choose the Ashdown ABM-600-EVO IV?

• Legendary ABM tone refined over 20 years

• 600W output – powerful enough for any stage

• Variable Valve Drive Plus – unmatched harmonic depth and overdrive

• 9-band EQ for total tonal control

• Sub-Harmonic Generator & compressor for huge, dynamic bass sound

• Tour-grade build & professional connectivity