DNA Stratus 2A3 amplifier - first impressions - Page 5

^ Thanks for opining for BA. I certainly meant no disrespect. I think Craig's HF filament loop is very innovative, and I know that there are many fans of his half-silver transformer. He is an honorable and creative member of our community who actively supports local meetings even here in Phoenix, and his products are top-notch.

Nevertheless, even though both of my local audiophile friends decided that they prefer their KR-PX4 BA's decked out with complete SAA cabling and LCD-2s to the Apex Pinnacle when we had it here for comparison, both also felt that the Pinnacle outdid their units in that it matched well with every headphone we tried, including the LA7000, HD800, DT880 and T1, whereas their KR-PX4 BAs do not. 

I have only heard the BA in that configuration. I'm not surprised to hear that the BA sounds great with lots of headphones when outfitted differently.

I certainly agree with you that the Stratus does not compete outfitted with its stock tubes, though that configuration may serve some folks well. Somehow Donald succeeded in selecting a combination of components that enable the Stratus to sound "juicy", as he calls it -- my word is presence. The KR-PX4 BA I heard didn't have that quality, to my ears. Outfitted with the cryo'd NOS 5U4G and the NOs RCA 2A3 blackplates together with the cryo'd NOS 6BQ7a that I have installed here, the Stratus produces clean, powerful, transparent and "juicy" music that is at least level with the KR-PX4 BA LCD-2 setup, and to my ears, more satisfying and very very close to the level of the Pinnacle. Of course, that's all based on my memory for SQ, and I am just as fallible as anyone else.

I invite you to try this combination and share your impressions. Orange Cty is mighty huge, but maybe you could visit Donald! Were you at  the Orange Cty HF meet last December where Donald showed off his prototype?

Quote:

Originally Posted by Anaxilus 

Yup I've heard Donald's amp 3 or 4 times now at different meets.  Always in meet conditions and w/ stock tubes.  Was hoping to have an extended listen under better conditions to confirm a few thoughts but haven't heard back yet.

 

I hope those conditions can be arranged!

I spent lots of time and money modifying my DNA Sonett, and IMHO, it is just as crystal clear as the Pinnacle. But replacing the stock tubes on the Stratus is all it took to have an amp that is nearly as transparent, considerably more powerful, and endowed with loads of "juicy" presence - the stuff of goose bumps, heart pangs and tears.

And obviously, since I pre-ordered the very first marketable Stratus, I'm a committed fan of Donald's choices in components - especially transformers, which he will say himself has a lot to do with the "juicy" DNA sound.

So, OK, full disclosure ---  I readily admit to being a bit enthusiastic! and I hope you get to hear it again!

ditto!  We will be looking forward to your comments!

The EML 2A3 meshplates have >150 hrs now, and they have changed considerably. They now provide quite a bit of emotion and presence, and the sound is still as clear, controlled and well-defined as before. They still provide impact. I would no longer describe the SQ as dry, and there is audibly more "you are there".  This using the cryo'd NOS 5U4G, which provides a more liquid sense of air than the EML rectifier.

The NOS 1940s RCA dual S-shaped blackplates still sound smoother, more liquid, and more emotionally involving, though with less clarity and micro-detail. The 3 string players in the Hyperion release of Brahms Piano Quartet No 1 Op 25 with Marc-Andre Hamelin are more difficult to separate when playing in unison than with the EMLs, but the music flows and so I am actually not interested in picking out detail, because I am enjoying the music-making. Same for the solo piano - easy to enjoy and "feel" the music in a wholistic way with the NOS tubes. The "impact" of the piano key strikes don't quite sound real with the EMLs. To my ears.

George at tubesusa said the tubes should have been "well broken in" by 100 hrs, but I will continue to give them extended playing time, both with music and with the XLO burn-in CD.

And the Sophia Electric Princess 2A3s (also meshplate) that I ordered should arrive by tomorrow.

Quote:

Originally Posted by Frihed89 

 

There are quite a few comments on the WWW about the dryness of the mesh plates.  A lot of people who have heard both prefer the carbon plates.  I've listened to neither.

Thank you very much, Frihed89. That could be my next direction. 

Oh, and one more comment. I happen to know that Donald spent time and effort looking for and testing out different types of feet, because I offered a few suggestions at the time. The ones he chose provide an outstanding level of vibration isolation on my rack - the 2A3s are notoriously microphonic, which you can easily verify with a light fingernail tap. The feet on the Stratus are so well-chosen and have just the right balance between support and compliance, that I need to rap the shelf that it sits on quite hard in order to cause tube ringing. From the next adjacent shelf, I can barely produce any sound. (and this with a $300 Sanus rack from Audio Advisor).

The only drawback is that they are short, and my well-aged fingers have a hard time slipping underneath to lift or move the unit. I guess if I were still doing rock-climbing, I would have retained sufficient finger-tip strength to lift the Stratus anyways!

But I guess that's really just kvetching after all ....

Hi Mark - great to hear from you here. Thank you very much for this suggestion. I felt a bit uncomfortable with that webpage, though, because it didn't really provide any description and the fotos of the two sorts actually looked like the same fotos turned 90 degr.

FYI, I installed Ultra SS Stillpoints under my VSMs, and last I heard, Bobby P was still auditioning them himself. And I tried those and lots of things under my Sonett, and finally settled on these easy-to-use and rather inexpensive feet

http://shop.mapleshadestore.com/Original-Isoblock-1s/productinfo/ISOBLOCK1-ST/

On a note of more general interest, I listened to the Stratus with the EML meshplates (burned >160 hrs) for ~3 hrs yesterday, and enjoyed it very much, more than with the NOS blackplates. Their transparent, detailed, dynamic, controlled and solid presentation now has enough emotional presence to be very satisfying.

But the Sophia Princess 2A3 meshplates arrived, and so they are now burning in. Their SQ has been different every time I peeked in, so I will wait to say anything.