I am thinking of buying a Marshall Valvestate 8240 and was wondering if anyone had any experience with these amps. Are they any good?
Also what is the watt rating of these amps? All i can find out is they have 2x 40w speakers. Does this mean it is 80w or just 40w and are they particularly loud?
Well, it's stero 40 watts. So, granted you have a speaker per side, that's 80 watts

I have an 8200, it's great! Fantastic even! I have it EQd for a perfect sounding old school death metal and heavier thrash metal sound, it is a real beast No need for a boost :P Loud too, considering I only run it at 50 watts.

Bear in mind it has a bite to the sound, which makes it sound lovely too. You might want to boost it if you're doing heavier than mid 90s death metal though (if you want mids).