Is there something I am missing?? I have the 404 going through the effects send/return on my 909, and the 404 in effects send mode...but I cant get it to work. I dont really need to do this, but I just wanted to try it out. Is there a special setting on the 909 I need to use? Thank in advance!

are you trying to use the 909 effects on the 404?

or the 404 effects on the 909?

The 404 Effects on the 909.

first off you need either:
2 sets of rca cables
and 4 rca to 1/4" adapter plugs

or:
2 dual mono 1/4" to rca cables (hosa makes some Guitar Center sells them)

hook them up like this:
909 effect send (L and R) to 404 line in (L and R)
404 line out (L and R) to 909 effect return (L and R)

then you need to turn on the EXT source button on the 404 and turn up the effect send level on the 909. im not sure how that works, i don't have one, refer to the 909 user manual for that part.

looking at the photo of the 909 it looks like you are going to set the effects send and return levels via that menu/screen somehow. i don't see dedicated send knobs like my dj mixer has.

um.. why does it need to be through 'send return'? just run the 909 through the 404