Dean Costello Audio Heavy Metal Warfare 50W HeadNotes The HMW (Heavy Metal Warfare) is the ultimate single channel amp for achieving all ranges of rock and metal tones. The impressive versatility it offers in this regard comes from having high and low gain input jacks as well as a high and low gain switch. Altogether, there are 4 levels of input sensitivity to choose from depending on how aggressive of a sound the user is going for. The high gain input ranges in sound from rock to extra heavy