@DoctaCosmos Hello man, I'm still quite a noob when it comes to tube rolling, but I got stocked up pretty hard the second I got the DV. Respect to the man who can keep his wallet closed lol.
I feel an RCA combo may be what you are looking for. I found them to be the brightest tube selection. I prefer my highs tamed and my lows deep as hell, my favorite combo has been Sylvania VT-231 + Sylvania 7236 or 6080.
RCA 6SN7 + RCA 6AS7G may be a good place to start and those are on the cheaper spectrum, which is beneficial if you don't like the taste.
Very detailed, but a bit to bright for my taste, highs were damn high.
@tej789 Sorry to hear about your problem mate. I would go along with
@atarione's statement in that you should pick up some cheap 6SN7s and maybe even a 6AS7 or 6080 just to test. With ebay they should be able to get to your place pretty quick, there is also a couple tube stores with their 70's style websites.
I also, like you, had an issue with my DV in the beginning like 3 days in, the left channel completely cut out from me. It turned out to be the DAC being weird, so at least if that ever happens to you its most likely a source problem and quick restart of the DAC will solve all your issues.
As everyone else has stated, the stock tubes aren't great (not bad, but not great) and it's true the DV, without modifications, aren't going to pair well with low Z cans, but there are some tubes that are better than others for low Z cans. Not sure what they are off the top of my head so hopefully another tube roller will jump in here for you.