Dr. Dre has said that his primary instrument in the studio is the Akai MPC3000, a drum machine and sampler, and that he often uses as many as four or five to produce a single recording. He cites 1970s funk musicians such as George Clinton, Isaac Hayes and Curtis Mayfield as his primary musical influences. Unlike most rap producers, he tries to avoid samples as much as possible, preferring to have studio musicians re-play pieces of music he wants to use, because it allows him more flexibility to change the pieces in rhythm and tempo. In 2001 he told "Time" magazine, "I may hear something I like on an old record that may inspire me, but I'd rather use musicians to re-create the sound or elaborate on it. I can control it better." Other equipment he uses includes the E-mu SP-1200 drum machine and other keyboards from such manufacturers as Korg, Rhodes, Wurlitzer, Moog, and Roland. Dr. Dre also stresses the importance of equalizing drums properly, telling Scratch magazine in 2004 that he "used the same drum sounds on a couple of different songs on one album before but you'd never be able to tell the difference because of the EQ." Dr. Dre also uses the digital audio workstation Pro Tools and uses the software to combine hardware drum machines and vintage analog keyboards and synthesizers.