I don't run a Cary 306, but I do have a Cal Audio CL-15 which has the variable output like the Cary. I have found that I prefer running a tubed pre-amp. The pre-amp takes out some of the harshness and makes it more pleasurable to listen. (Cal Audio CL-15 - Cary SLP-50B - McCormack DNA .5) You may want to consider this option, I have found that many people prefer this type of set-up.