Best 6NS7 Preamp for a Pass Labs XA25 amp

I have a Supratek Sauvignon that uses the 6SN7. Sounds really good.
I also have had a chance to listen to "The Dodd" battery preamp hooked up to my XA-25. Incredible. would have loved to had a longer listen. I think it uses a 6922. I'm going to roll a few through the Supratek in the next few months and see if I can get a little more air. 

pfeiffer - May I ask you which Dueland caps she used and did you send your unit to Kara herself to do the upgrade?  Also, how would you describe the sonic change from the original caps which I assume you were using before the upgrade. Thanks!

@gadios Can you report on the ss kit you referenced?

For people who don't know, Wayne Coburn is the designer of the pass labs preamps. I'd like to give it a shot to compare against my Don Sachs pre (I have first watt f4 mono blocks).

Just curious what it's called...

Don Sachs custom pre.  A stunning 3D, holographic unit with the right speakers.  Uses those killer Miflex caps and the new WE Plus series Shuguang 6sn7's.  In the past I wouldn't have given you a nickel for a chinese tube, but this new Dawning series is a concerted effort by the top chinese techs to build the best current production tubes.  I've had mine for a couple months now and I just live it with Spatial Audio OB speakers.  The music just surrounds you.  That suggestion of the lightly used one from someone above is a great suggestion.