humming or buzzing sound from pioneer ddj sb

Contacting service is probably the best bet, they can tell you if there is a problem with the unit itself.

@Job > You may have a ground-loop. Consider using a transformer-based hum-eliminator to reduce the noise.

thank you where do I get this ? transformer based hum-eliminator?

Job Raoul J. Lamela, my Sb had the same problem and it was a burnt preamp. Better contact the service

Hey guys. I too own a DDJ-SB, and had this problem just now.

I accidentally nudged my "Mic Level" knob located to the left of the unit, and it affected the buzz noise.

When it's turned all the way down, the buzz appears. When turned all the way up, the buzz is still there.

But when the knob doesn't touch its limits (i.e: full mic volume, or no mic volume), it works fine.

Hope this helps!

I am currently using pioneer ddj sb which I purchased less then a year a now & currently I am experiencing a buzzing or humming sound when I connect the sb to a mixer or a sound system, furthermore it gets worst if I connect my laptop adaptor to my laptop. The mic volume control knob just keeps on turning.

Sounds like there is some type of electrical grounding issue.  Try using a ground loop isolator or removing the grounding prong on the mixer's power cord.