Despite the watery divide between them, Brooklyn-bound Greg Schappert and London-based Tom Russell have fostered a production partnership as Donor / Truss for the last six years, emerging today as one of techno's more robust and hardworking duos. As solo artists they've racked up notable releases between them on labels like Stroboscopic Artefacts, Perc Trax and Our Circula Sound, outside of Schappert's own Miniscule imprint. Meanwhile Russell has been stepping out as the acid-charged MPIA3, lately flexing a 'less is more' approach with outings on Avian and R&S.For Grey Series 05 they don the Donor / Truss moniker once again after a spell apart, proving themselves as accomplished and unpredictable as ever with the fully formed 'Aber'. On the A-side swampy techno is bruised with house in 'Spacial', turning soupy on the sluggish and barely rippling 'Beneath'. Fidgety 'Ease' then does an about turn on the B-side before plunging headlong into swollen substrata stuff on the close.