This is the second thread I've started on this issue. The problem: The preamp tubes in my DB750 are microphonic. Tombowlus suggested that I get a gramma pad to cut down on the sound vibrations from the cab (directly underneath the amp), and I did. The gramma pad has made a noticeable improvement. But I still get some ringing from time to time and I think I just want to get a new set of preamp tubes. I noticed that Tombowlus mentioned in wnother thread that he tried Telefunkens on his db 750 with great results, so I'd like to give them a try as well. I respect his opinin and figure I can;t go wrong with the Telefunkens. So: Where do I get Telefunken preamp tubes for my DB750?