I have a FM Transmitter connected to the Line Out jack on my home theatre system, which transmits to the shower radio in the bathroom. (I don't like the music of the radio stations in this area, haha.) My problem is that the output of the stereo is too loud and sounds distorted on the radio. My home theatre doesn't have a headphone jack, so I can't adjust the volume. Is there some small, cheap external device I can connect to the Line Out of the stereo to adjust or limit the volume?