Boiler Room stage isn't necessarily representative of all the other stages, but even when I do a quick search for dekmantel boiler room I still find some techno stuff:
https://www.youtube.com/watch?v=zYZwfvYUAdA
https://www.youtube.com/watch?v=fJqXu9x0tX4
https://www.youtube.com/watch?v=GXFF98eBplc
https://www.youtube.com/watch?v=Bj8425Ma6F8
https://www.youtube.com/watch?v=Ww9VtKqprUY
https://www.youtube.com/watch?v=GzVLrWxV6Ao
https://www.youtube.com/watch?v=favzGST2joI
https://www.youtube.com/watch?v=cXqzqaa9bIU