Thanks Bob for all your help .About the volume i will double check to make sure my volume is all the way up on my computer .Even when it was lower i still had plenty of volume so i guss that is showing me that the usb connection is pumping a better signal from my computer compared to the 1/8 jack hook up . So it's volume all the way up on the computer and lower the volume on the mixer i got it. I talked with Mackie tec support today .He said both out put connections are ok either 1/4 or XLR connection but he said like you said the XLR gives a less chance of interference with Noise .As of now i have a 1/4 inch jacks going from my mixer to the input of my power amp by way of XLR connection. I orderd a pair of Pro co XLR cables today from sweetwater .I like the idea of the jacks being the same set up on both sides male to female connection XLR and like you said it looks less messy becuase the jacks are on the back. Again thank you and the forum for leading me in the right direction .

Regards,
Greg