I have a pair of 40w Quicksilver Mid Monos.... they are great amps!!!! Dead silent ,sound excellent with EL34 or 6l6 type , built like a tank. Mine are a little over 5 years old and have been rock solid reliable. I have had a few tube failures and either nothing happened or the fuse blew as it should with no damage. I have had several tube amps in the past and these are my favorite. I’m running a pair of Heresy III and it is a perfect match.