I am using a Krell FPB 200 with a AE-3 tube line level pre-amp. There is a section in the Krell Users Manual which will explain the use of Tube Equipment with their amps. An internal jumper/switch needs to be changed in the amp before use with tube equipment. I called Krell told them what I wanted to do and they faxed me the instructions. The instructions are easy to follow and it only took 5 minutes. I have not had any problems and am very happy with the combination of tubes and SS equipment.
