Hello,
I have a problem with the djay Pro version on Android.
The issue occurs with the lack of sound when I try to play a track through the DDJ 400 console with external speakers connected via RCA cables (master out). On my phone, I have selected the USB DDJ 400 option.
Hey @Szlojdra_Adus - Welcome to the Community! Thanks for your first post. 
Apologies for the delayed reply!
To answer your question, unfortunately, the Pioneer DDJ-400 is not natively compatible with djay for Android. You can find a full list of natively supported hardware via the link below:
I apologize for the inconvenience and wish I had a better answer for you! Please let us know if you have any further questions; we’ll gladly help.
None of those controllers are natively compatible on Android.
The headphone jack doesn’t work so you CANNOT precue the next track.
This means your only option is to hit play, start fading the next track in, pray that the beat grid is correct and that it sounds reasonable.
This is not an acceptable way to DJ and Cannot be used with any level of professionalism.
I wouldn’t even DJ like this at a family barbecue.
So whatever you do, DO NOT purchase a controller from the list that Algoriddim keep pushing!! Once again they are providing false, misleading information.
