Btw is your 12AT7 to 6922/ECC88 adapters bought from Pulse Tube Store? Or from somewhere else?The rectifier tubes: RFT EZ81 (w/ foil getters);
The power tubes: Mullard / Philips 6080;
The driver tubes: Brimar CV455 (KB/FB - Footscray plant).
Used in rotation are Tung Sol 5998 (power) and RFT ECC81 (driver w/ foil getters).
Sound is: . With no music playing and volume at maximum, very light hum. At 1.5x normal listening level, no hum. This is my best setup for high impedance headphones: Beyers, Senn, ZMF.
asking cause these looks white not silver/copper showing in your post: https://pulsetubestore.com/products...uction-base-9-pin-b9a-noval-not-made-in-china