They aren't really incresing their work load by 4x because their turntables have 4 arms, as pointed out here: https://news.ycombinator.com/item?id=14961307 htt

They aren't really incresing their work load by 4x because their turntables have 4 arms, as pointed out here: https://news.ycombinator.com/item?id=14961307 https://news.ycombinator.com/item?id=14961307