I have already looked through several topics on various forums where people had an identical problem and I did not find the answer in them. What I'm trying to do: by routing (1/4 jacks - rca) through Audio 10 1/2 channels out and input create a track in Ableton with 1/2 in and route it to return channel with PSP42 delay with 1/2 out; (I also tried to create just one clip with PSP42 and 1/2 in, out) When its done on DJM800 I set two encoders at the snd / rtn and master positions respectively, then raise the level / depth encoder to the 12 o'clock position or max, press the button ON, I send some sound and get nothing at the output. Another way with outputting 1/4 jacks to mono mic jacks works, but I'm wondering why the snd / rtn channel is not.