Are any further meets in the works, I have the Valhalla 2 with stock tubes running off an Audio Engine D1. I am wondering what the next logical step is, upgrading tubes or looking at a new DAC. Any thoughts?
It depends on your budget and what your future plans are. The equipment you have is low/mid-fi, are you planning on upgrading to high-fi or do you want to stay where you are?
If you want better sound stage go for the HD800s, obviously they are the king of the HD line and king of soundstage alltogetherI. The HD800s can sound boring and sterile and lack bass if you don't pair them with the right amp though.
I don't think a dac is going to make anywhere near as much of a difference in soundstage as an amplifier unless you have a really crappy dac.
Tuberolling helps and you can achieve huge changes in how your amp sounds from rolling tubes depending on the design of the amplifier.
On of the biggest things you can do to open up the soundstage is to upgrade the coupling capacitors if your amp has any, but that is a can of worms you probably don't want to open unless you know what you are doing.
no tube is going to you the clinical detail resolution of a solid-state amp
That depends on the amp. I've heard many of the top end big name solid state amplifiers ranging from $5000-$12000 and nothing has ever come close to the realism and detail (not to mention the overall sound quality) of my current tube amp (heavily modified LD MK6) not by a long shot. In fact, depending on the quality of the sound track it becomes hard to distinguish the music from real life, it's kind of spooky (and not to mention amazing).
I'm currently in the middle of designing and building a monster headphone amplifier that will blow away anything you've ever heard, loosely based on the design of my current amplifier although there won't really be anything left of the original design when I'm done with it. I can't imagine how it can possibly sound better than it already does but from an engineering perspective there is huge room for improvement.
I'm hoping to have a finished prototype complete by May, until then I won't be attending any meets.