I have a Simms Watts MKII head which has two channels (normal/brilliant), with two inputs per channel. What is the difference between the the the inputs? (High/low gain is not stated). As far as I can tell there is not much difference between them.. What is the difference between high and low gain inputs anyway? I read somewhere that it is possible to bridge the two channels, for more gain. What does this mean? Will it make the amp louder by using both channels (more tubes?) simultaneously? How do you bridge them? Thanks!