When he was fourteen, Walker's family moved south from Newcastle to Milton Keynes in Buckinghamshire, 45 miles northwest of London. It was here that he acquired his nickname due to his northeastern "Geordie" accent (which he has subsequently lost).
Walker moved to London to study architecture and became a founding member of Killing Joke in 1979 when he responded to an advertisement placed by the singer Jaz Coleman. He had never played in a band before. Walker and Coleman have been the only constant members of the group since.
His preferred guitar of choice is a golden, hollow-bodied 1952 Gibson ES-295:
I was at Peter Cook's in Ealing, looking for a guitar called the Gibson ES 225T, which is a thinner version of the ES 295, anyway, he had an ES 295 and I fell in love with it. This old guy had been playing it locally in jazz clubs. I took it home, plugged it into the Burmans, and the sound was there - a full resonance, and totally bell-like with the sustain on it through 250 watts of amplification in stereo. You can feel the thing vibrating, it's a huge sound. I tune the guitar in D (below bottom E) and my strings are really thick, I use an 062 on the bottom, and because of the way I tune the guitar, the strings still have the same response as a normal guitar would. The amplification makes the bottom end sound unreal. The guitar cost me £660, and I've seen them going for a grand. The paint's all worn off the neck of mine, but the sound of the guitar is a lot sharper, a lot clearer than other ones I've heard.
Having started out with a Burman amplifier with custom Burman 8 x 10 cabinets, He currently uses 2 x Framus Dragon Head amplifiers, he has also recently experimented with a Marshall Vintage Modern which he describes as being similar to the Burmans (specifically the use of 4 pre amp tubes and KT66's although the Burmans had KT77's power amp valves).
Walker's effects include two PA:CE (Parmee Acoustics and Collins Electromagnetics) Automatic Double Tracker units, one under the Bell Electrolabs brand (one of the many sub brands PA:CE sold their products under) and the other under the PA:CE brand name. He has also been known to use an Electro-harmonix Memory Man for echo effects during the 1980s, and recently has been using two Line 6 Delay Modelers, as well as a T-Rex Roommate (reverb effect).