Although you won't find his name in their catalog, producer and mastering engineer Stefan Betke was closely associated with the Berlin-based Basic Channel label and its artists, such as Maurizio, Monolake, and Vainqueur. Like those artists' bassy, dub-laden reductions of techno and house, Betke's work -- which appeared under the alias Pole, named after Waldorf's 4-Pole sound-processing device -- was about doing more with less. Snaps, clicks, crackles, and smudgy bass atmospheres occupied the whole of Pole singles such as "Tanzen" and "Raum Eins," as well as Betke's numbered 19...