DNA Stratus 2A3 amplifier - first impressions
Aug 26, 2015 at 8:20 PM Post #2,401 of 4,456
I am also keen in the Solaris given how much I love the Stratus, and with Donald, there is no doubt about the quality of the new amplifier. I can only hope that I don't get priced out.
 
Bigfatpaulie, do update us when you hear more details from Donald!
 
Aug 26, 2015 at 8:51 PM Post #2,402 of 4,456
  I am also keen in the Solaris given how much I love the Stratus, and with Donald, there is no doubt about the quality of the new amplifier. I can only hope that I don't get priced out.
 
Bigfatpaulie, do update us when you hear more details from Donald!

 
You betcha.  Nothing back from him yet - I called at 14:12 Eastern time.  Hopefully I hear back from him tomorrow.
 
I spoke to Craig Uthus about 2 weeks ago and he has more transformers than 20 so that amp will have a slightly larger production run than originally stated (but you didn't hear it from me).  If the Solaris is a thing I will take my name off the EC list.  What can I say, I bleed blue thanks to DNA.  Either way, I still wasn't 100% sold simply because I didn't want to give up my Stratus.
 
I am also assuming that the production Solaris will look a little better than these test amps...  Right?
 
Aug 27, 2015 at 1:41 AM Post #2,403 of 4,456
I called Donald and left him a voice mail today.  I suppose this is in response to The Studio.  Very interesting...  Do you know if this will be a limited run?


Thanks for your voice message Paul. I was in meetings all day and will call you tomorrow. To answer your questions, the Solaris is a dream I have had for the past 6 years. I first reached out to Audio Note about some custom 2A3 headphone transformers back in July 2009. They are very busy but after 6 years of patience and persistence, they finally developed a custom pair of output transformers to my specification. I received them earlier this summer and they sound fantastic. They have the musicality of those in the Stratus together with greater resolution, clarity, layering, dynamics, and bass slam. Because of their capabilities I have been revisiting all of the other components to match their sound quality and resolution. For the coupling capacitors, yes I plan to use the Duelund CAST copper foils. I prefer the sound of top coupling capacitors to non-nickel & silver, unshielded interstage transformers. This amplifier will also feature balanced XLR inputs and I just received notice today that my balanced input transformer samples shipped today from Audio Note. I want to use the best sounding components to me. This will be a regular model to be released in early 2016.
 
Aug 27, 2015 at 1:50 AM Post #2,404 of 4,456
Is there a possibility of the Stratus being upgraded with balanced inputs? Essentially a consumer version Solaris, but with less "boutique" components to hit a lower price point?
 
Aug 27, 2015 at 2:07 AM Post #2,405 of 4,456
I will look into this possibility. Space inside the Stratus is tight and I need to see if there is room to fit the balanced input transformers.
 
Aug 27, 2015 at 8:20 AM Post #2,406 of 4,456
Thanks for your voice message Paul. I was in meetings all day and will call you tomorrow. To answer your questions, the Solaris is a dream I have had for the past 6 years. I first reached out to Audio Note about some custom 2A3 headphone transformers back in July 2009. They are very busy but after 6 years of patience and persistence, they finally developed a custom pair of output transformers to my specification. I received them earlier this summer and they sound fantastic. They have the musicality of those in the Stratus together with greater resolution, clarity, layering, dynamics, and bass slam. Because of their capabilities I have been revisiting all of the other components to match their sound quality and resolution. For the coupling capacitors, yes I plan to use the Duelund CAST copper foils. I prefer the sound of top coupling capacitors to non-nickel & silver, unshielded interstage transformers. This amplifier will also feature balanced XLR inputs and I just received notice today that my balanced input transformer samples shipped today from Audio Note. I want to use the best sounding components to me. This will be a regular model to be released in early 2016.

 
No worries at all!  I am best to reached in the afternoon if that is at all possible for you.  
 
Thank you for the additional information, I very much appreciate that.
 
I was reading Anaxilus' impressions and sounds like the 20A and the Solairs are very different animals: makes it hard to choose!  
 
Anyway, looking forward to hearing for you.
 
All the best.
 
-Paul
 
Aug 27, 2015 at 12:06 PM Post #2,407 of 4,456
I am SO-O-O-O excited about the Solaris !!!
 
I know that it will have the sound quality that Donald wants.
 
Oh BOY Oh Boy Oh BOY !!!!
 
Aug 27, 2015 at 12:52 PM Post #2,408 of 4,456
No worries at all!  I am best to reached in the afternoon if that is at all possible for you.  

Thank you for the additional information, I very much appreciate that.

I was reading Anaxilus' impressions and sounds like the 20A and the Solairs are very different animals: makes it hard to choose!  

Anyway, looking forward to hearing for you.

All the best.

-Paul


The 20A is a concept headphone power amplifier from an idea of creating a minimalist, ultimate single tube DHT amplifier intended primarily for the HD800 and other higher impedance dynamic headphones. It is a special unit for a select audience. I first demonstrated it to some friends back in December 2014.

The Solaris is more an all-rounder, like the Stratus, with improvements in all aspects of the listening experience.
 
Aug 27, 2015 at 2:52 PM Post #2,409 of 4,456
The 20A is a concept headphone power amplifier from an idea of creating a minimalist, ultimate single tube DHT amplifier intended primarily for the HD800 and other higher impedance dynamic headphones. It is a special unit for a select audience. I first demonstrated it to some friends back in December 2014.

The Solaris is more an all-rounder, like the Stratus, with improvements in all aspects of the listening experience.

 
Interesting - so the 20A really is THE HD800 amp (at least, in your eyes)?
 
Be prepared for an onslaught of questions by the way :)
 
Aug 27, 2015 at 3:07 PM Post #2,410 of 4,456
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Aug 27, 2015 at 3:33 PM Post #2,411 of 4,456
   
 
Be prepared for an onslaught of questions by the way :)

 
First one is : what's the price for the 20A amp. asked Donald for the Solaris amp but forgot to ask for the other one. 
 
Aug 27, 2015 at 9:24 PM Post #2,412 of 4,456
DNA4.jpg

 
 
I want to start by giving a HUGE thank you to Mr. Donald North for taking more than an hour out of his busy day to talk to me.  It was both a pleasure and privilege talking to him.  He is a gentleman and highly intellectual.  Hearing him talk about his designs in the level of detail that he can go into is awe inspiring.  He is clearly someone that truly loves what he does, and more so than ever I am convinced of his passion for his craft and art.  His amps are truly single serving, purpose built masterpieces that stem from his love of our hobby. 
 
I tried to take notes while talking with North but often I got lost in conversation with him and neglected to write down as much as I should have.  Everything below is not a direct quote from Donald North and it is all paraphrased.  I may be incorrect in my interpretation or memory so he may correct anything I’ve said below.
 
About the two new statement amps from DNA Audio: The Solaris and the 20A.
 
 
DNA1.jpg

 
 
 
Q: Two statement amps can be confusing to a customer.  Part of the pleasure of buying a statement piece like either of these is that the owner won’t feel like they are missing something, and in this circumstance that seems almost unavoidable.  Why two different amps?
 
A: The Solaris was started years ago and was always a goal of North's to build.  It is not a reactionary amp, but something a long time in the making.  Take everything that the Stratus did and ramp it up to the extreme – the very best parts, the very best matching the very best performance.  The Solaris has a similar signature to the Stratus.
 
The 20A is built out of inspiration.  The EML 20A tube caught North’s eye and he wanted to build an amp around it.  The 20A has a unique signature and the amp was built specifically with the HD800’s in mind.  It is an extreme idea, with extreme implementation. 
 
Q: What kind of valves does each amp use?
 
A: The Solaris will use the same set as the Stratus – a 5U4G, 2 X 2A3’s and most likely a 6N1P as an input tube. 
 
The 20A uses a 5U4G rectifier and 2 EML 20A (either mesh or solid plate) and that’s it.  There are no rolling options for the 20A aside the two EML variants.
 
Q: What is the power output of the Solaris vs the Stratus?  What about the 20A?
 
A: The Stratus and the Solaris output about the same power.  The 20A will have a slightly lower output.
 
Q: Are speaker taps an option given the output on either amp?
 
A: Nope.  Speakers require different power than headphones and as such, in a perfect world, the transformers in the amp are designed to meet those different demands.  Both the Solaris and the 20A are purpose built amps for headphones exclusively.  They are very focused in their design to master this particular niche.  To achieve the level of performance that these amps are capable of with headphones, sacrifices had to made and not driving speakers was one of those sacrifices.
 
Q:  Have you tried either amp with the Abyss? 
 
A: No, not with either amp but he hopes too.  Neither will likely be the best match for the Abyss, however.  The Abyss needs gobs of power which neither amp outputs.  Additionally, the 20A with its very particular signature, likely won’t compliment the Abyss the way other amps can.  The Solaris may be an okay pairing, but again, its power output may not be enough to really maximize the AB-1266.
 
Q: I personally find the Stratus to be a bit of a one trick pony – it is exceptional with the HD800 but for some other headphones different amps may be a better choice.  Is the HD800 still the focus or will either of these amps be better suited to more headphones?
 
A:  Yes and no.  Most Stratus owners use either HD800’s or LCD2/3’s.  The Solaris customer will likely be best served by these same headphones.   The Solaris, like the Stratus, will also work well with the TH-900’s, T1’s, K1000’s, etc.  The 20A, however, is built specifically for the HD800's and it is meant to provide the best possible presentation for them specifically.  The Solairs is more versatile.
 
Q: What cans/source have you been using to develop this amp?
 
A: A Sonic Frontiers SFCD-1 CD player (with a tube stage!!) is the primary source used while tuning and doing critical listening.  Headphones used are primarily the HD800’s and K1000’s but a few others do roll in once and a while.
 
 
DNA3.jpg

 
 
Q: Why the addition of balanced?  Was it peer pressure?  It was peer pressure, right?
 
A: Yeah…  A little bit.  Plus, it has been exceedingly difficult to find input transformers that he liked and could get in ample supply.  Well, he’s found them.  That said, both amps are ‘single ended’.  The Solaris uses the input transforms only when using the balanced in.  Single ended just bypasses them meaning that the performance will likely be a little better single ended.  The 20A on the other hand requires the use of them with either input type.
 
Q:  Because these input transformers are really expensive, would a non-balanced version (for less money) of the Solaris be an option?
 
A: Maybe.  The issue is the chassis.  These amps are boutique products and the everything is ordered in very small batches so having a lot of variety in the cases presents a new challenge.
 
Q: The 20A has no volume pot – why?
 
A: Due to the nature of the 20A an attenuation with an analog volume pot isn’t an option (it’s super technical).  You can use the output of an active preamp or the volume control on your source.  A passive in-line attenuation device isn’t an option, it will really mess with the sound.
 
Q:  Will the Solaris use the same TKD pot?
 
A: Yes - right now but North has his eyes open for something better that is available consistently in production and quality.  The TKD (in the Stratus and Solaris) is a Japanese made pot to exacting standards and he personally prefers it to the British P&G.  North is not a fan of stepped attenuators (neither am I personally) as he feels that exacting control is important.  North also hand inspects each pot individually before installing it to ensure that it is smooth and consistent in its operation.  Now that’s attention to detail!
 
Q: Sounds like the Solairs takes everything the HD800 does well and masters it - clarity, midrange, imaging, etc.  The 20A helps the 800's weakest area - the bass, etc.  Is there no way to combine these two strengths to make an idea combination?
 
A: They are just so different in their presentation.  For example the Solairs is a very up front sounding amp - first row if you will.  The 20A is more mid-hall.  The Solaris does expand on the Stratus on all fronts, including bass texture and slam.  20A is a purpose built HD800 driver.  Combining them is like asking to a tank with a Lamborghini – both excel at specific things but you just can’t combine them.
 
Q: Can you share pricing on these amps?  No pressure and I won’t hold you to it.
 
A: The 20A will be in the neighborhood of $8000 and Solaris will be somewhere between $6000 and $8000, depending on the cost of a few key components.
 
Q: Will these both be regular production amps?
 
A: Yes, for sure the 2A3 amp.  The 20A is a bit more difficult.  It requires very special shielding over the transformers and, frankly, that special shielding looks ugly because it is military grade stuff.  North is looking for a way to “pretty it up” and make it look high end by either polishing, painting, plating or just adding a second enclosure.  The shielding also has a high nickel content so it oxidizes.  I personally really appreciate that Donald North is taking such great care to ensure the esthetics coincide with the sound.
 
 
DNA2.jpg

 
 
I pulled several “Columbo’s” on Donald – just one more thing…
 
Q: Why is the Sonette and Sonette 2 (by the way, it is pronounced “Son-Ette”) no longer in production?
 
A: The demand was low compared to the Stratus so he decided to focus on what the masses were after to keep production as quick as possible.
 
Q: What are the production facilities like?
 
A: The DNA amps are built by two people: Donald and a friend of his in their spare time.  They truly are hand made by request.  The amps, chassis and many parts are made and sources in good ‘ol So-Cal.
 
Q: How many Stratus (Strati?) exist?
 
A: 47.
 
Again, a HUGE thank you to Donald North who was so very gracious; I greatly enjoyed our conversation and I hope it is the first of many.  I was both humbled and inspired by his patience, willingness and profound understanding of his profession.  I personally cannot want to listen to these two amps and have tentatively placed an order for one: which remains to be determined.
 
I can’t wait.
 
Aug 27, 2015 at 10:50 PM Post #2,413 of 4,456
Thanks Paul, for taking your time to write and update us on the 2 statement amps! :bigsmile_face:
 

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