you can use it up to 42v. i use a toroidal transformer powersupply so rest voltage is 41-42v.. voltage drops down to 34v at bass. i useit with a pair of 100w 4ohm speakers. it doesnt even get hot. the fan never never spins up. im oly raising the volume to 75% tho.very good amp. minimal noise only audible from close to the speakers even tho im using a long aux cable and long speaker cables.
everything is all right like all orders before