Need more info

What is your source? Where are you coming out of your mixer? What are you using to get from the mixer to the sound card? How are you moniroring the signal (speakers or phones, input or output)? What software are you using? Is input monitoring enabled?

I use a Boss GT-6 effect unit which has left and right output & goes to channel 1 + 2 of the mixer with 1/4' trs cables.

From the mixer to the soundcard I use 1/4" trs cables also. It goes from the mixer's main output or sub 1 & 2 output to the input of the soundcard. Here is where I am getting all the problem. Getting alot of feedback from the recording.

I use pc speakers to monitor which is enable, the software I work with is Guitar Track Pro.

Hope this info can help. thanks!!!

I still need more information to "solve" your problem. It may be easier if you tell me what you want to accomplish, and I help you configure your set up from that. There are many different ways you can connect a guitar processor, mixer and sound card together, each one having a different purpose. Doing something wrong can cause things like feedback. You also mentioned “mono sounds” and “hissing sounds” these things are probably not related to the “feedback”.

If, like I suspect, you intend to use this set up to record yourself playing over the software's backing tracks, your best bet is to go directly from the output of the GT-6 to the input of the sound card. Then, just monitor the output of the sound card directly. You really do not need the mixer. If you intend to do something else, it may be a different story.

If you are actually getting feedback (a high pitch squeal or howl), it means that you are creating an audio loop. This most likely is not between the speakers and source because you are using a guitar pickup, not a mic. So, it would have to be internal (meaning within the system rather than between the speakers and a mic). If BOTH inputs AND outputs of the computer (any sound card) are connected to the mixer, AND your software has input monitoring enabled, it could cause internal feedback. "Input monitoring" may be called something else, and is likely to be enabled by default in software intended for guitar.

A mono sound could be cause by panning within the mixer or software. It could also be because, without the right processing, a guitar (originally a mono signal) will sound mono. Hissing can be caused by just about anything in the audio chain with a bad gain structure (the relative positions of all the volume/level/gain controls in the audio chain). Such as, if the gain of the mixer channel is turned way up and the fader is way down. If I'm interpreting your description of the problem wrong, please explain the symptoms better.

-Jon

I got it to work. thanks for ur time and help Jon Lewis.

Please post your solution so others with similar problems may be able to be helaped by it.
Thanks,
Jon