One aspect often getting lost is the relationship between driver and power tubes. On my Wavac EC300b I use different driver tubes depending on which 300b tube I am using.
With Takatsukis the best result is achieved with Tungsol 6l6G coke bottles, using more high powered 6L6GCs (eg. JAN Philips...
Just updated my Zenith Mk3 to Sense 2.6.0 Wowza!! Another significant increase in sound quality particularly relating to dynamic range and separation of instruments. InnuOS comtinually improves performance and user interface of its Sense app. The Qobus integration is exemplary.
On a whim, I doubled my Sommer Cable 75ohm BNC cable between rubidium clock and DAC using BNC T-junctions. The resultant improvement in clarity, sound staging and impulse response was simply revelatory. It goes to show that in digital audio better clock means better sound.