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If you're asking if you can play a record while using rekordbox dj or dvs with the DDJ-SX2, the answer is yes. When you flip the channel input switch over to PHONO - the software will show that the input for that deck is from the turntable rather than the software.

And once you have timecode playing, go to the DVS page and click the AUTO button below the deck to calibrate the tone, and the START button to the right to calibrate the balance.