HBE Hematoma Bass Overdrive/Pre-Amp
The Hematoma is a 2-channel bass pre-amp/overdrive pedal, made by HomeBrew Electronics (HBE), a small Phoenix-based handbuilt effects company from Arizona, USA. Other pedals that the company makes include the Germania treble booster and the Power Screamer, which is their most known product.
The Hematoma is a fairly standard bass pre-amp and overdive pedal in terms of controls, featuring standard gain, level and tone controls with a pre-gain knob, allthough the tone itself is a little fatter, compared to other similar pre-amp pedals like the classic SansAmp or the MXR. Additionally, the pedal has an "EQ Shift" switch, allowing for it to change the sweep of the tone knob, providing a warmer and smoother tone when engaged. The Hematoma also has two foot-switches, one for overdrive (BO) and another one for pre-amp (BP). Both can be used separately or combined.
Wolstenholme used this pedal since The Resistance tour. He has said in an interview with Bass Player Magazine that the pedal was used for the slap-bass sound on Undisclosed Desires.[1] It was likely used for the same purpose on Panic Station. Allthough matte black, the pedal was spotted having a checkered black/blue pattern in the Dunlop TV rig rundown, which means Chris repainted it sometime during The Resistance tour.