simple stereo mixer, how to connect pre-fader AUX

[Dimitree]

With the help of the book "Small Signal Audio Design" (Self Douglas), I'm trying to design a simple and cheap line mixer, mainly for monitoring.
I've tried to drawn a simple stereo input channel and this is what I came up with so far.
Now I need to connect the three pre-fader AUX sends. I want the stereo signal to be mixed in mono before hitting each AUX send.
I've seen various schematics where the signal from L and R is passively summed with 3.3K resistors. But I don't understand if I should take the signal before or after C15.
What would it be the difference?
Should I put additional coupling capacitors too?

thank you and sorry for the noob question

 

[laitue5]

Hi, did you build it?

 

[snakecained2]

The words " Simple and Cheap" never seem to apply to my DIY work.

 

[ruffrecords]

It is unusual to want a mono AUX send from a stereo channel. However, perhaps the simplest way to achieve it is to use dual gang pots for each AUX send. Drive one from the L signal and the other from the R. Then simply simply feed each pair to the same bus vis identical bnus resistors.

Cheers

Ian