Master output too loud and noisy from DDJ1000

I am facing strange issue with my DDJ1000 rekordbox with macbook m1 pro 2020. I use UDG USB B to USC C connector. No USB hub in between. I ma using rekordbox latest version.

Recently I tried couple of times to connect master out to external audio mixer. The output signal seems too strong even I put master volume really low. And that also leads to distortion. Bass output is too much. In past I connect master out to DJM mixers and never seen this issue. Anyone have any idea? Thanks for your help.