Karl O'Connor (aka Regis) has been a brutal instigator on the techno underground for over 15 years, instrumental in pioneering the disturbing situationist inventory that came to embody the mid 90s 'Birmingham sound'; slate grey monolithic chunks of audio, charged with oblique hypnotic undercurrents.

While his music sits (un) comfortably as purist techno, the overall aesthetic (and that of his Downwards Records imprint) owes far more to industrial and post punk than any conventional electronic trajectory. Throbbing Gristle, Cabaret Voltaire and Coil have all been referenced as influences but, like much of the best techno, his music exists in the moment - a spontaneous outpouring that eschews conventional form, instead focussing on violent functionality.

And it's this very functionality that has come to define Regis. He's spoken of his desire to create "massive slabs of sound" and the vast majority of his tracks are exactly that. Often based around four or five oblique samples looped together ad infinitum, it's when manipulated in the mix that his music makes the most sense - layered, chopped and EQ'd his tunes take on pure physicality. Indeed much of his early output comprised relatively basic DJ tools and, although he's released five LP's, the innate practicality of the sound has ensured that the loudly pressed 12" has often been its most successful home.

As such, the prospect of a three CD retrospective may seem intriguing – anathema, even - to the nihilistic immediacy of Regis' techno. Is the spectre of the collector box not treading perilously close to canonised respectability or cosy product fetishism? In this case it is not. Rather, the 47 tracks that make up Adolescence offer a visceral insight into the bloody-minded vision of a true, and very English, techno pioneer.

Charting his complete work from 1994 – 2001 it's plain that on the very early pieces - 'Speak to Me', 'Model Friendship'– musical ideas outstripped means of production. Sparse and overdriven to the point of distortion they just about stand up, but lack the drastic punch of later work. It is not until the penetrating grind of 'We Said No' that the classic Regis sound comes to the fore – all brittle snares, layered subs and unrelenting industrial percussion.

Tracks from 1998 genre classic Delivered Into The Hands of Indifference sound particularly fresh, especially when taken in the context of the current vogue for darker atmospheric techno. The endless build of 'Concentrate', the stunted shuffle of 'Escape From Yourself', the pervasive hum of 'Indifference'; all revel in a dogged, pummelling sparseness, subliminally unsettling in their aural effect. By using loops that change almost imperceptibly, the mind starts to add and subtract elements independently of the source material.

By contrast the tracks taken from eponymous follow up LP Regis show slightly more restraint, with even a faint nod to Chicago in the oscillations of 'Adolecence' and 'Executive Handshake'. 'Execution Ground', meanwhile, is one of the few tracks to feature any kind of vocal adornment, utilising a haunted tribal chant that ducks around under the mix.

But really it's the influence of industrial that give Regis' work its unique flavour. Classic themes – submission, dystopia, violent sexuality, urban despair – permeate track titles ('Get On Your Knees' 'It's a Man's World' 'Broken on the Wheel') while the artwork, too, is classically industrial in focus; the shots of anonymous stairwells and concrete blocks reveal a logical affinity with brutalism. It's important to note that the tracks here are all inexorably linked to their birthplace, a seething aural evocation of the industrial West Midlands. Just listen to 'Penetration' – pneumatic, incessant, factory funk; Regis humanises industrial grime into something ultimately transcendent - machine music made for dancing.

With its emphasis on his early loop based techno, when taken as a whole (go on, try… ) this compilation does suffer slightly from lack of colour – indeed it's a sense of continual refinement, rather than full scale musical progression that is heard here. Only later tracks such as 'White Stains pt 2' or 'Thirst' hint at what Regis has gone on to deliver since 2001 in the form of the finesse of the Sandwell District collective, progressive bludgeon (with Surgeon) of British Murder Boys and, more recently his best, surprisingly delicate, solo work for Blackest Ever Black.

Thus, all indications point to the satisfactory conclusion that Regis very best work lies ahead, rather than behind him. But taken as document of youthful bloody mindedness; of the sinewy thrill of Birmingham techno; of the seedy, narcotic, blackly humorous world of Karl O Connor, Adolescence delivers in absolute spades.