It is not recommended to run only one channel of a two channel amp. The reson being, the outoput transistors of most amps require a balanced load across both channels. I too would suggest turning the gain down to a level that works for your application.
A closed mouth gains no foot.
1977 CJ5, '75 258, Motorcraft 2150 carb, HEI dizzy, BDS 2.5" suspension, 3/4" Daystar Rock Krusher Greasable shackles, M.O.R.E. steering brace, Flaming River steering shaft, Tie rod flip, Yukon AMC20 axle kit, 1.5" Trail Sport wheel spacers, 15x10" Black Cragar soft 8s w/ 33" Yokohama Geolander MTs, Goodridge SS brake lines, Classic Tube stainless hard lines, YJ power brake with front disc upgrade (had 4 wheel drums)