Delgado performed in the Los Angeles-based band Socialistics, a frequent opener for Deftones, when the Sacramento alt-metal outfit began asking him to provide additional sounds and samples to their music. He was a guest performer on several songs on the group's first and second albums, Adrenaline and Around the Fur, and was formally inaugurated into the group just before their third release White Pony (2000).
In the late 1990s and early 2000s, it was not uncommon for hard rock or heavy metal groups to have a DJ. However, Delgado stood apart from the pack due to his creativity; his playing rarely featured traditional scratching or beat juggling. Instead, he tends to use turntables as a sampler to integrate subtle sounds and textures into the music, remisicent of electronic music, ambient, or even musique concrète from the 1940s and '50s. Good examples of Delgado's inventive touch include "MX" (from Around the Fur) which features distorted human laughter and a strange, pitch-shifted sound vaguely reminiscent of glass breaking in slow-motion; the quieter moments of "Digital Bath" (from White Pony) feature burbling, watery noises.
With the band's fourth album, Deftones, Delgado began to put more emphasis on keyboards and synthesizers as part of his repertoire. Delgado has also commented that he creates his own samples, rather than use pre-recorded sample banks or borrowing sounds from other artists.