Jah said I've had my BHK pre for 4 weeks now. I have installed the Tungsram 7dj8s last week. I love what I hear with these. Compared to the stock tubes, there's a more realistic presence, and I'm getting a kick out of being able to pick out individual saxophonists in a big band -- something I like doing when listening to a live band!A question: under what circumstances would one change the bias jumper? I changed the voltage, but left the bias at the factory setting. Is this a correct configuration for the Tungsrams?
The intent of the bias or tube operating switch was to allow for the use of the 12AU7 and the 6922 family of tubes. For the 6922 types, the current was set for 5 mA and for the 12AU7, 4 mA. It would be interesting to see what you think of the sound when set at 5 mA vs. what you observed when set at 4 mA, the factory setting for the 12AU7.