Since the early '90s, AtomTM (Uwe Schmidt) and Tobias Freund have been exploring techno’s outer limits in live sets performed on synths and drum machines. This collection gathers eight different recordings captured in places like Helsinki, Berlin, and even Valparaiso, Chile, but you could be forgiven for not realizing that it covers a nearly quarter-century span. Since the beginning, the duo’s tools and aesthetic have remained largely unchanged: From modest hardware setups they wring endlessly hypnotic sequences, entrancing dancers with shape-shifting drum patterns and long, undulating acid lines. In the 1992 sets here, from Helsinki and Montreux, their cycling counterpoints and rigid grooves walk a thin line between techno and trance; by 2005’s performances in Paris and Zürich, retro acid-house aesthetics intermingle with the stripped-down palette of 2000s minimal. To experience the full effect of one of their performances, dig into the five hours of Berlin 2014, in which 40-plus minutes of ambient dub techno provide the scene-setting intro for a mind-melting journey into psychedelic synth riffs and cavernous reverb. The occasional hint of crowd noise places you right in the action; few documents of Berlin’s all-night party culture feel quite so lifelike.