I was considering picking up a Marshall Valvestate 150 watt guitar head, and using it with my 8 ohm Marshall cabinet. The minimum ohm rating of the head is 4 ohms. I know it's safe to do so, since one fellow at Marshall already told me that's okay, plus in the manual they discuss which jack to use if you are going to be playing an 8 ohm cabinet.
Thing is...what about wattage loss and volume loss? If I use a 4 ohm head on top of an 8 ohm cabinet, is the amp effectively only putting out 75 watts then? And then I will lose some punch and volume?
Is there a reason hybrid amps and all solid-state amps don't have impedance switches like tube amps do?