Thanks for the reply. I'm familiar with Win4K3's capabilities and have gone that route in the past. I wanted something a little more comprehensive. If I just wanted the temp of the amp I could set the LCD on the amp to report temp. One wouldn't need Win4K3 for that. Since I have Win4K3 and the DDU I would like to use both. Looks like a DB9 manual switch may offer the most economical way to do this. Again thanks for your thoughts.
