Update - 6H30 DR tubes

I posted on March 10 some information about 6H30 tubes. After that I read an AudioAsylum posting claiming the superiority of 6H30 DR grade tubes over standard Sovtek 6H30EB tubes in Audio Research LS25 mkII pre-amp. Having been a 100% satisfied owner of aforementioned pre-amp I nevertheless decided to give it a go, and placed order for 4 DR tubes of the highest quality. I know there has been a lot of rumors concerning tube vendors re-labeling either EB or EV versions as DR - and charging double price. So choose your vendor carefully, I used TubeStore. Price per tube was USD 55, other costs were UPS Express delivery of USD 26 and various EU VAT and duties of Euro 58.

The sound? I have to be careful here, otherwise I might lose all credibility, but in short the best value for money upgrade I have ever done. Even after some 10 hours of burning-in, DR tubes demonstrated to be way superior to standard Sovtek tubes. The full run-in tubes give the ARC sensuously textured midrange, and eerie presence with which it reproduces voices and solo instruments. The DRs produce a dramatic, palpable three-dimensional sonic picture with superior sense of scale. The bass is slightly drier and better defined, and the overall system has better musical grip and ability to tightly control Revels' woofers. In short, DR tubes make ARC to sound more substantial, colorful, and dramatic, more musically involving.

I have to confess that part of the improvement might occur because at the same time I replaced crappy O-rings ARC installs as standard feature by Herbie's Audio Lab tube dampers.

Viewpoint: I perceive DR grade 6H30s with tube dampers as essential upgrade to ARC LS25 mkII. Before posting this I even ordered 4 tubes more from Tubestore in order to have 3 spare pairs.