Preamp 6922 tube help

Nice digital system! The CCa tubes are really revealing units. Basically you have upgraded up to the point that you are hearing the true nature of the sonics of your DAC, the AC power that is feeding it, and the files/discs it plays.

EMI and RFI are enemies of the character of a DAC's highs. Every time I have used an EMI/RFI line power filter on a DAC the digital glare calmed down. I highly recommend you try one on your DAC.

Here is what I am talking about, 

http://www.newark.com/te-connectivity-corcom/10et1/rfi-power-line-filter-10a-500ua/dp/52K4501  

There are much smaller filters available but the one I link is vastly overrated so it will pass current freely to your DAC. 

The problem is that it has to be wired into you power line feed to the DAC. I have always spliced them into an IEC power cord or a normal power strip. 

There are plug and go solutions like Furman but the filters in those are not nearly as strong as the Corcom I linked.

Every time I have used these I have never regretted it.   

loungeaudio +1     Dirty power is most commonly the cause of edgy HF - especially with a SS DAC.   The OP describes his system but no mention of power cleaning.    Is there any?

A second or third vote in support of the Matsushita/National 7DJ8 tubes, I dropped 6 into my preamp about a year ago and they sound excellent. I would characterize the sound as more neutral than warm, with excellent detail. Not sure they are what the OP is looking for but an excellent tube and superb value.

I haven’t rolled 6dj8 equivalents in a long while, but I preferred to Tele to the Siemens, even though the Siemens was probably the more linear tube, the Tele sounded more 3d in the mids. I suspect it was the character of the circuit. I think the "right" tube for you is perhaps even trickier since you are compensating for the aggressiveness of the DAC.
Brendan at TubeWorld, already mentioned, has a pretty good handle on the sound character of NOS tubes and as I recall, he does allow a return.
I’ve used him for years and he’s proven to be a reliable supplier.
I struck gold recently with the Tubemonger- he had some NIB Genelex (GEC) EF86 tubes that were flying lead types that he converted to "normal" tube pin bases. These complement the GEC KT 66 power tubes that I got from Brendan (not easy to find either) for a pair of vintage Quad II amps. I’d reach out to both shops and get some advice.
I roll very little in my main system these days-- the odd rectifier for the phono stage, and one small tube--a 12ax7- in my power amps. I’d say any advice regarding a particular tube will be in a vacuum (sorry) given the balance you are trying to strike.
Out of curiosity, do you have another source that doesn’t use the DAC- and did you reach similar conclusions regarding the tubes you’ve tried so far?

So for power I found power supply with some type of toroidal transformer to be cost effective enough, the preamp has a lps, and the people who design my dac went really far and wrote a white paper a few pages and talked about the effort they put to clean the power. 

The issue pretty much goes away with a switch of tubes. I'll try to change sources and see but I'm pretty sure it's the tubes. 

I got some tube recommendation and ill give it a try.