Boss

[Hexhclass]

When the input switch on that amp is see the the high position the amp plays audio way louder that when it is set to low.I can not find anything wrong in the preamp section so am wondering if it is normal for that amp?

 

[Piasa]

Normal, just a preselection depending on your signal source.

 

[Perry Babin]

It could be a switch to allow the amp to be used with a wide range of input levels.