I've started using the Hifiman Edition X's exclusively. The presentation is much richer than the EL-8's. For my WA6, I received the Brimar 5Z4G and I think that it's equal to the Sophia Princess 274B for a fraction of the price. I've installed 6SN7's from Langrex also. I have 6F8G's coming in the next week for some tube rolling fun. My bass and Midrange are great with a good soundstage and punch. However, the treble and resolution and decay are still missing in the A/B between the HD-DAC1. I just hear layers of more music in the SS amp/dac. The interconnect is a quality Kimber Silver Streak so I think that maybe the dac isn't delivering the same quality of signal at fixed RCA outputs. I don't have another DAC to do A/B on. Any ideas?
Yes, wait until you burn-in the Brimar and receive the 6F8G's before doing anything.
After that, if you feel you need another DAC you could buy my PWD-ll w/Bridge-ll.