Make sure your cable from your amp is plugged directly in to TX 1 Jack. Then go to Radio settings and click TX settings. Select RCA TX 1 and click Enable. Under Max power type in the recommended wattage number of Manufacture not to overdrive the amp. If using ALC, click under Hardware Enabled. You will adjust the desired ALC level with the tune button engageged and the slider. Set the tune slider to 10 watts. Next to Mic then adjusted desired Mic Gain. Then you should be good to go.
Julie