Contrarians to a man, Faust have been at turns my favourite and the most problematic of all the Krautrock bands. Proto-industrial punks who approached experimental music with a DIY spirit many of the more academic groups of Germany's disparate avant-rock movement lacked, Faust could also seem luddite, clumsy, as likely to break a machine as to channel its smooth, sublime process. Early recordings like So Far and The Faust Tapes can sound both dated and stormingly ahead of their time. When I saw them play, in 1998, following a mid-decade re-form, the big guy threw a telly, the other guy angle-ground something, someone pumped noxious gas through the Garage and we filed out, choking and euphoric, and I was high for days (on adrenalin, not the gas) but couldn't remember any of the songs. Something had been summoned and come to life, but the music itself was ephemeral. They could be weirdly macho and wacky, and beautifully cerebral and ascetic. It's because of them I heard Tony Conrad, yet for years I didn't listen to them at all.

Faust - Feed The Greed by theQuietus

They were, and are, a wonderful headache, and confusingly split into two separate Fausts soon after that '98 gig. One incarnation comprises the big telly-throwing one, Zappi Diermaier, and the little French one, Jean-Herve Peron, who tour a fun but slightly turgid industrial farm-klang around the place with classic Faust props like cement mixtures and horseshit, a sort of post-apocalyptic Asterix and Obelix. The other is the more considered, studio-led group helmed by Hans-Joachim Irmler, whose Faust Studio and Klangbad label have been the source of recordings by Finnish motorik-metallers Circle, noise/hip-hop duo Dälek, US avant-folk group Christy and Emily, and Fluxus-inspired Nista Nije Nista.

If Irmler's Faust have been the more oblique and collaborative of the two until now, double CD Faust Is Last is a firm statement of intent, lasting around 90 minutes and mooted to be Faust's final album under that name. The first CD, 'Faust A', is mixed loud, with the trademark shards and shades of chaos neatly aligned to 16 tracks of propulsive space rock. It reminds me the most of Circle, whose northernmost metal-schooled take on krautrock knocks seven shades of shit out of any contemporary band you might have seen lately trying to 'do' kosmische rock music. Their pummelling yet spacious motoriks are such close relatives of tracks like 'Imperial Lover' and 'Chrome' that I'm surprised not to see Tomi Leppänen listed on drums or hear the ursine rumble of Jussi Lehtisalo on vocals. This is high praise for Irmler's current band, who, while channeling a vintage sound through not only trance-out rhythms but soaring riffs, phased, chromatic organ lines and flutters of oscillator, maintain momentum on tracks that could easily have dragged beneath the weight of their own heritage. Drummer Jan Fride, who's perhaps most responsible for the tight, airborne feel of the record, is another krautrock veteran, a founder member of prog outfit Kraan; his forty years in the service of out-rock have been channelled into beautifully minimal grooves like 'Steinbrand', which spends its entire five minutes riding a hazy, phasing peak of pleasure, post-dynamics, post-everything, in the motorik's blissful now.

It's a little disheartening to come down to earth with tracks like 'Dolls and Brawls' and 'I Don't Buy Your Shit No More', a Stooges-ish fuck-the-Man jam voiced by Lars Paukstat. Why, I'm not sure – Faust have always been refreshingly willing and able to knock out a garage-rock banger alongside the experimentation, after all – but these retro moments jar on an album that, pretty much throughout, argues for the mystery and vitality of rock music, not its preservation. Perhaps I was expecting something more contemporary from a band whose last Klangbad release was the bleak, urban sprawl of their 2004 collaboration with Dälek. Second CD 'Faust Z' reassuringly heavy on the atmospherics and alienation, however, and in its denisity and dark saturation not dissimilar to Derbe Respect, Alder. Percussionist and noise artist Z'ev is credited as 'executive producer', an artist who shares with Faust the ability to make industrial textures sound both exciting and alienating – exciting not in a power-trip, giant robot way but in a breathtaking, occult, trespassy way: the secret life of machines; the earth's hum; the beauty of waste and scrapes and scraps. Irmler and Z'ev, on the controls, ricochet organ stabs around the mix and pull the bass from beneath your feet. Z'ev's ear for sharp, elegant metallic textures is more in evidence here than his penchant for punishing scrapyard noise, and Steven Lobdell's guitar on 'Softone' is a dreamy, Popol Vuh-like fantasy, also akin to Japanese explorers like Makoto Kawabata or Suishou No Fune; elsewhere, we hear Boredoms in ecstatic cymbal smashes, homemade techno drum circles and cyclical, lift-off jams.

Faust - Karneval by theQuietus

For a band initially so confrontational and so self-contained, holed up in their Wümme studio commune in the early years of the 1970s, Faust's open-ended, tricksterish sound has spread since across genre and geography; a quality that isn't always apparent until you start trying to trace their legacy and end up in Osaka, Newark, Sheffield, Berlin, Helsinki. Yet they – both theys – and the sound they make, still end up somewhere utterly Faust: a sort of permanently amorphous, haphazard, stark zone that echoes with harsh and playful ideas. And this is somewhere they've inhabited throughout their best work, and are inhabiting right now, however much Faust Is Last's promo blurb proclaims that the album looks only to the future, leaving the past behind. Past and future mean nothing in this context: space is all; and if this is really is Faust's last, it closes the door on that space with a typically – and satisfyingly – irreverent and reverberant slam.