Here's a quick demo of the Marshall Class 5 in my apartment. If it sounds a bit muffled/mushy its because I had to put pillows around the mic to try and keep the volume down. A cranked Class 5 = unhappy apartment neighbors!
I may try some different tubes. I've heard a tube swap + allowing the speaker to break in can help open things up.
I'm really liking it so far. Well done Marshall, I can see why you have been making some of the most famous amps in the world.