Help with mixer-interface-laptop setup

[Rainer Straschill <moinsound@googlemail.com>]

Andre,

from your description it's hard to judge your problem properly, so I try:

You have your signal source (whichever) connected to some input of
your mixer. Some output of your mixer goes to your audio interface,
and the interfaces goes back into your mixer. Then the mixer goes to
some kind of PA/headphones/whatever.

When you play your source signal into the mixer, you hear it through
your PA and also some kind of slapback version of it (not phaser-kind,
more like a slapback).

It's most probable that your interface or your computer software sends
your source signal back to the mixer. To try that, why don't you
connect your source signal to your audio interface, the interface to
the PA and see if you can hear the originall source signal. If that is
the case, then the interface is the problem.

Some more throughout description of your setup (what is patched into
what, what software are you using etc.) could also help.

Best,

          Rainer