@gmbt2K, thank you for your perspective. That's very smart to employ silver cabling. Coincidentally, I also use a silver power cord as it provides that same sort of flavor you alluded to.
You're also right about NOS EL34. We had a series of tube shootouts at my home in the past. One session dealt with EL34 and KT88. Given the aforementioned plug and play simplicity, we used the DA60, and only waiting a few minutes for the tubes to cool off just a tad slowed us down. We had some newer variants, and they offered what we considered decent sound. But when the vintage Mullard EL34 stepped up, they sounded so far superior from top to bottom, no further discussion took place.
That said, JJ E34L seem to have a special synergy with Jadis amplification, and placed second in our shootout. They're not the last word in low frequencies, but produce a stellar midrange. In fact, on some fixed bias amplifiers, like my Jadis Orchestra Reference, Dynaco ST70, and Quicksilvers, they sound flat out glorious. They don't produce that level of amazement in the DA60, but the overall sound of that amplifier bests the others. Going back to the low frequencies, you can win that back with the right 12AX7 driver tubes in the DA60. So these JJ tubes definitely have my recommendation as something for you to try without breaking the bank. Apart from the vintage Mullards, there are other EL34 I like a lot in other applications, but for the DA60, I won't list them here