Head of Doom – Geezer Butler Signature Bass Amp Head

The Ashdown ‘Head of Doom’ Geezer Butler Signature Bass Amp Head. Hand built in the UK, the Head of Doom was designed around Geezer Butler’s very requirements.

The Ashdown and Geezer Butler story began three years ago after extensive talks with Geezer’s long standing tech, Terry Welty. Black Sabbath’s ‘The End’ farewell tour was approaching and Geezer was extremely specific about his bass sound for the band’s departing tour. Ashdown designed a rig for Geezer to leave a bold statement with, encapsulating a music career spanning 50 years into one sound to remember the almighty Black Sabbath by.

The Head of Doom is for bass players who seek classic, driven bass tones with phenomenal power. Stripped back, the Head of Doom is built on Ashdown’s flagship ABM range; offering tried and tested tone and rock-solid reliability

Geezer Butler Head of Doom



Made For ‘The End’

The Ashdown Geezer Butler Head Of Doom Signature Bass Head was built for Black Sabbath’s final farewell tour and had to deliver rock solid performance night after night. It was made with extensive talks between Ashdown and Geezer’s long-standing tech, Terry Welty. Geezer was extremely specific with his requirements and needed an amp that was capable of covering a 50 year music career. The result is the Head Of Doom, delivering powerful performance and true rock tones.

666 Watts Of Beastly Power

The Head Of Doom Signature Bass Head pumps out 666 watts of power, with a tube preamp for warm saturation and a solid-state power section for authoritative, stage-covering sound. It is designed to accommodate input from both passive and active basses or, as Geezer Butler used on stage, the transformer isolated output from another Head Of Doom – ”More heads – more doom!”

Tonal Shaping Features

The Head Of Doom includes a versatile 3-band EQ on both the mid and bass controls, alongside the standard bass/mid/treble controls to give you focused tonal sculpting. This EQ is footswitchable allowing remote switching on-stage for instant tonal changes. A ‘Doom’ control adds increased pre-amp current to the 12AX7 valve for more overdriven grind and fatness. This level adjust can be preset and also switched via remote footswitch.

Sub Harmonic Doom And Level Controls

A ‘Subs’ switch gives the Head Of Doom an extra layer of octave-below harmonic content which can immediately thicken your sound and produce an earth-shattering wall of sound. The amp includes dual VU meters so you can get your input level and drive perfectly matched to the output level, and there are also dual inputs for either passive or active instruments.

Professional Connectivity

The Head Of Doom was designed to be used by Black Sabbath through multiple cabinets and with multiple heads acting as slaves for a master head. This is all made possible through the wealth of sound connection options on the back of the amplifier including a tuner output, line out, transparent FX loop and a line input for the connection of an external sampler or sound source. There is also an output muting function which still leaves the tune-out active for live silent tuning. Three transformer isolated outputs allow you to feed amps into further amps to drive multiple cabinets, or allow you to tap off a signal for recording purposes.

Available from November 2017

 Buy the Head Of Doom

Geezer Butler Head of Doom


Power Output 600 watts RMS into 4 ohms.
Power Requirement 115 – 230 Volts
Speaker Configuration 2 x Neutrik Jack/Speakon outputs
Frequency Response -3dB an 17Hz and 22kHz
High Instrument Input Impedance 3.9m Ohm / Input range 50mV to 15V p-p
Low Instrument Input Impedance 10k ohms / Input range Input range 300mV to 30V p-p
Line Input Impedance 22k Ohms / Input level 0dBu nominal
Line Output Impedance 10K Ohms / Level 0dBu nominal
DI Output 600 Ohms balanced / Level -20dBu nominal With Ground Lift
Tuner Output Impedance 22k Ohms, level 0dBu nominal
Impedance Minimum 4 Ohms
EQ 9-Band
Effects Send Impedance 22K Ohms / Level 0dBu nominal
Pre-Amp Tubes 1 x 12 AX7
H x W x D (mm) 127 x 431 x 279
Weight (kg) 31lbs / 14kg

Watch the Geezer Butler Amplifier Rig

This amplifier head was featured on part 2 of our Geezer Butler Amplifier Rig. If you haven’t watch it yet, we invite you to do so by following the link to the show notes for the episode.


Buy your Head Of Doom this Christmas

 Buy the Head Of Doom

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