Very interesting discussion! Learning a lot. I grew up with a father that had all McIntosh tube equipment and large corner horn klipsch speakers. My ears were tainted at a young age :-) I recently purchased a Valhalla and Napa-Acoustic NA-208C CD player. I switch between listening to CDs and FLAC on Fiio F3 with my 650s. My office mate got a Woo W7 just to show me up. I'm feeling a bit jealous but not sure if that is warranted.
I'm considering adding a Bifrost DAC and using the digital out of the CD and F3. Do you imagine this will produce a noticeable change in sound?
I am intrigued with the idea of trying different tubes with my Vahalla. I read this whole thread and there is a common theme of "tubes from Mr. Tom". How does one arrange for a set of "tubes from Mr. Tom"?
On the topic of tube rolling what is some advice on the best way to remove and replace tubes so as not to damage the Vahalla or the tube itself. Do you use your fingers to rock the tube out? I had a hard time getting one of my stock tubs into the Vahalla. What about a "socket saver"? Will these impact the sound?