DNA Stratus 2A3 amplifier - first impressions
Dec 26, 2012 at 6:17 PM Post #392 of 4,464
I believe the choice of 2A3 is everything with this amp.  Incredible variation in staging, treble response, airiness, bass clarity, resolution, punch, everything.  My current favorites are NOS Ken Rad dual boxplates.  I have a pair of NOS Sylvania dual monoplates on order that may top those according to what I've read. The RCA black s-plates are very nice too, very neutral and balanced.  The EML meshplates add a kind of *humidity* as we've been discussing that is quite unique and pleasing.  I have not yet tried the Sophias.  Next I will be experimenting with rectifier variants.  So far the EML 5U4G is better tonally than the EML 274B but both are topped by a simple NOS RCA 5U4G for resolution and balance.  The EMLs add a little too much coloration to the bottom end for my taste, although they are enjoyable for other reasons - like slam of sub bass.  I will report back once a few more arrive. 
 
Dec 29, 2012 at 10:58 PM Post #393 of 4,464
Quote:
I believe the choice of 2A3 is everything with this amp.  Incredible variation in staging, treble response, airiness, bass clarity, resolution, punch, everything.  My current favorites are NOS Ken Rad dual boxplates.  I have a pair of NOS Sylvania dual monoplates on order that may top those according to what I've read. The RCA black s-plates are very nice too, very neutral and balanced.  The EML meshplates add a kind of *humidity* as we've been discussing that is quite unique and pleasing.  I have not yet tried the Sophias.  Next I will be experimenting with rectifier variants.  So far the EML 5U4G is better tonally than the EML 274B but both are topped by a simple NOS RCA 5U4G for resolution and balance.  The EMLs add a little too much coloration to the bottom end for my taste, although they are enjoyable for other reasons - like slam of sub bass.  I will report back once a few more arrive. 

 
fejnomit, thank you very much for sharing your impressions of this variety of possibilities. You have a very nice collection already, and your descriptions are clear and graphic. I certainly agree that the choice of 2A3 makes a huge difference. I think Donald's choice of OPTs do, too.
 
I'm not about to leave my Princess / HD800 combo yet. I did swap the EML solids in for a day, and the T1 and LA7000 liked them, but the Sophia's enhance the Stratus presence and as much ambience as a disc has.
 
And I made a direct comparison with my modded Sonett, and the depth of presence and richness of sound with the Stratus immediately stand out.
 
 
 
I hope the other new Stratus owners will share their experiences, too.
 
smily_headphones1.gif

 
Dec 30, 2012 at 12:22 AM Post #394 of 4,464
budx3385, on your recommendation I have ordered the Sophias.  I recently modded my HD800s and have fallen in love with them again so I want to give this combination a try.  The Sylvania 2A3s fell through, by the way.  NOS matched pairs are getting harder to find.  The supply really is drying up globally.  All the more reason to find the current manufacturers that are good.  I'll report back about the rectifiers.
 
 
Dec 30, 2012 at 12:26 AM Post #395 of 4,464
Oh, and when I said the choice of 2A3 is everything with this amp, I didn't mean to imply it is the single largest determining factor of the over all sound of the amp. The Jensen caps and the output transformers are arguably a larger part of the "Stratus sound."  But since those are not easily or casually rolled, I was merely referring to those aspects of the sound that we can control.  So, in other words, the choice of 2A3 matters more than the rectifier, more than the input tube and more than the fuse.  Power cord has made a large difference - but I know not everyone feels this way, so I usually leave that out...
 
Dec 30, 2012 at 1:26 AM Post #397 of 4,464
When developing the Stratus, a lot of time and listening was spent auditioning different components, from the coupling capacitors, plate and grid load resistors, cathode bypass capacitors, etc., to arrive at what I thought was the best sounding balance to me.
Quote:
Oh, and when I said the choice of 2A3 is everything with this amp, I didn't mean to imply it is the single largest determining factor of the over all sound of the amp. The Jensen caps and the output transformers are arguably a larger part of the "Stratus sound."  But since those are not easily or casually rolled, I was merely referring to those aspects of the sound that we can control.  So, in other words, the choice of 2A3 matters more than the rectifier, more than the input tube and more than the fuse.  Power cord has made a large difference - but I know not everyone feels this way, so I usually leave that out...

 
Dec 30, 2012 at 1:07 PM Post #400 of 4,464
I would listen to the amplifier from a few days to a few weeks with a particular set of components, familiarizing myself with the overall sound, then switch one and note the differences heard. If it was an improvement, I would then listen and get acclimated with the sound and then change a different component, again noting the difference. In my experience with quick A/B comparisons, you can hear gross differences but not so easily the subtler differences. I used the K1000, DT770 Pro 80, DT931, K240DF, and even some Triports. I also had a couple friends listen and share their observations, who used HD800 and LCD2.
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Interested to know how you compare components? do you run two units side by side and do quick A/B? which headphone do you normally use?

 
Dec 31, 2012 at 1:09 AM Post #401 of 4,464
Well, your method has surely paid off.  If I didn't already love the *stock* sound you have achieved, Donald, all the rolling in the world wouldn't make a difference.
Bravo on having great ears and great patience.  Of course the circuit is a large part of the sound as well - but again, not something we would want to mess with aftermarket.
 
 
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With the Stratus + HD800 combo, what DAC seems to compliment this the most?

 
And it terms of DAC, I have been using my Stratus with my RAM-modded W4S DAC2 with stunning results.  The DAC has been outfitted with a Silver Rock output transformer and Audio Consulting silver wire and the level of resolution is outstanding.  Fed into the Stratus, it is highly recommended.
 
Jan 1, 2013 at 1:50 PM Post #402 of 4,464
Quote:
budx3385, on your recommendation I have ordered the Sophias.  I recently modded my HD800s and have fallen in love with them again so I want to give this combination a try.  The Sylvania 2A3s fell through, by the way.  NOS matched pairs are getting harder to find.  The supply really is drying up globally.  All the more reason to find the current manufacturers that are good.  I'll report back about the rectifiers.
 

Congrats on the Sophia's, I'll be interested to hear your impressions vs the other 2a3's. What mod did you do to your HD800's and what changed you mind on them?
 
Jan 5, 2013 at 8:16 PM Post #403 of 4,464
Quote:
I would listen to the amplifier from a few days to a few weeks with a particular set of components, familiarizing myself with the overall sound, then switch one and note the differences heard. If it was an improvement, I would then listen and get acclimated with the sound and then change a different component, again noting the difference. In my experience with quick A/B comparisons, you can hear gross differences but not so easily the subtler differences. I used the K1000, DT770 Pro 80, DT931, K240DF, and even some Triports. I also had a couple friends listen and share their observations, who used HD800 and LCD2.

 
 
Sensational advice, Donald, and I believe that same advice is relevant to system matching in general. We often talk that talk here on Head-Fi, but how often do we walk the walk ?  :wink:
 
Jan 5, 2013 at 11:18 PM Post #404 of 4,464
Unfortunately for my day job I walk that walk far too often, my friend - trying new combos of tubes, phones and cables when I should be working...
It's all about the endless shuffle toward that ever-shifting perfection...
 
Jan 6, 2013 at 1:28 PM Post #405 of 4,464
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Unfortunately for my day job I walk that walk far too often, my friend - trying new combos of tubes, phones and cables when I should be working...
It's all about the endless shuffle toward that ever-shifting perfection...

 
I suspect that you and I are walking in very different directions if that is the case - I was referring to Donald's suggestion that we make a single change and settle on that combination for weeks before changing anything else. As far as your job goes, I'd count my blessings - 2013 could prove to be a very interesting year for all of us. 
 

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