As producer, remixer, or engineer Vrenna has worked with U2, Nine Inch Nails, Scar the Martyr, Gary Numan, Lords of Acid, God Lives Underwater, Megadeth, Rammstein, Metallica, The Rasmus, Weezer, P.O.D., David Bowie, Slipknot, Cold, underwater, Scarling., The Smashing Pumpkins, Hole, Marilyn Manson, Rob Zombie, Green Day, Live, Adema, the Wallflowers, TheStart, Dir en grey, and Psyclon Nine.
Как продюсер, ремикшер или звукоинженер Вренна работал с Lords of Acid, God Lives Underwater, Megadeth, Rammstein, Metallica, The Rasmus, U2, Weezer, P.O.D., Дэвидом Боуи, Cold, underwater, Scarling., The Smashing Pumpkins, Hole, Marilyn Manson, Робом Зомби, Green Day, Live, Adema, Wallflowers, TheStart и Dir en grey.