DJM-900 REC out manual says -8db standar, what is the max?

Don't play in the red and you won't have any problems.

yes in the ideal world lots of good things would happen, yet in the real world is not the case, whe have many top 100djs using the djm.900nxs, almost all of them keep everything in red, you can check us at cosmobeat.com , and of course others site alike  be-at.tv , boilerroom.tv among others will happen the same, theres no point going further on this.

so** i need to know the maximun output db at the rec in order to build a list of suitable sound cards, thanks**

If the DJ u know is surely gonna hit reds just lower the output level via the mixer's internal menu settings

Switch off before they arrive... hold down the utility button while switching the power back on follow the menu to the d-out level (between -19dB & -8dB and master attn down from 0dB to -3dB or -6dB) 

Keep in mind in that with digital once you hit 0dB the signal is destroyed forever. There is no way to ever recover that audio- so best to leave the rec out at -19dB and just fix the volume on input of the soundcard or later in post. 

ANY audio interface will do. The mixer has 19dB of overhead and that means you can run 19dB into the red on the mixer before it clips.

hi there, thanks for your answers

master att does affect rec out?

d out level (usb) does affect rec out too?

the -19db overhead is pre ch or pre master?

http://youtu.be/8ol7fFSPSu0?t=47m43s here you can watch our latested recording, at 47m 40s you can hear saturation/distortion, also at 1h 00m 00s seems to be digital clip