well, in true Marshall fashion…it only gets loud untill about 5 then after that it just gets raunchy and nice. I can get pretty friggen loud though. As you would know from having one they are solid state, but its a good solid state at that, being MOSFET. It sounds a LOT like a JCM800 however I don’t like dealing with tubes so it’s great for me. The amp is 100W at 4 ohms, meaning of coure at 8 ohms with one 412 cab it would only be around 50W. The added 412 would cut it down to 4, and double the wattage. The output is generally 3dB louder for doubling the wattage, so….take what I have now (which is friggin loud) and add 3dB to that. I have had some volume issues with it though, There are like three volumes on the amp and to get the thing really loud you have to turn them all up somewhat. The master volume can be all the way up but if the volume to the right of that isn’t up, you can hardly hear it (well, it’s still moderately loud but in comparison you know…).
In all, I like it and am looking for another one. I used to like the M-80 more because of it’s bluesy sound and soul, but I hardly ever play on it anymore.