Danny,
This doesn't sound quite right. I don't understand what you're saying "There is just not enough volume to drive the PA without having to vrank the PA volume up to the point of distortion." If there's not enough gain coming from the headphone jack it could never distort the front end of the PA. Maybe the soundcard is just defective and is distorting period. You just don't hear it until the PA is up.
Something is defiantly queer about this.


John
ESI Gigaport HD+
Lenovo Turion II /4 Gig Ram/ Win7x64 be
15.6" Monitor
"The only Band is a Real Band"
www.wintertexaninfo.com/BANDS/JohnnyD.php