Hello, I just purchased a use m147 and I would like to know some info about the estimated tube life, type of tube needed when replaced, cost of tube etc.. ALso, I would love to have Klaus contact me regarding 'sweetening' the mic. I am a baritone to Tenor jazz singer/Balladeer ala Sinatra, Bennet, Ect.. and will be running it through a Neve 1070 Clone and ADL1000 (unless someone has a better idea...)into a 24/96 Firewire interface. Any advice is appreciated.. Eric