DNA Stratus 2A3 amplifier - first impressions
Aug 23, 2013 at 11:29 PM Post #1,096 of 4,456
On the topic of transformers, as Donald has noted, a transformer per se is not automatically a better thing.  They have to be the right transformer and that - for me at least - was the problem with the EC gear I owned and why, in the end, I sold both the ZD and the BA - tone.  Although I don't agree that either amp has anywhere near the resolving power of the Stratus - or that they have a wider soundstage either - I did NOT find this to the case - it really came down to a question of the way those retrieved microdetails sounded.  EC sounds to my ears veiled.  Like there is some nice cotton and teflor dielectric between me and the music.  This, after endless tube and cable rolling, I determined was a result of the Electraprint transformers that Craig prefers.  I do not think they sound - watch out - real.  It's an effect that can only come out through direct comparison of one amp with another - and through deeper searching of one's own personal feeling for music.  It's like those times when you're listening in your car and you say to yourself - wow this XM jazz station must have some pretty high end equipment, this **** sounds dope.  Then you go to your main speaker rig and listen to some of the same albums or musicians and you are suddenly transported into a realm of organic reality that had been utterly missing from the car experience.  In relation to itself the car sound was balanced and detailed and quite dynamic.  But in comparison to a 45-based amp, for example, it is revealed to be a digital simulacrum of an instrument and a voice.  Like playing around with a higher-end synth and thinking - wow, that really sounds like a sax - and then you listen to Sonny Rollins' Saxaphone Collosus on vinyl through an all DHT playback chain and you hear an actual, tangible brass instrument pumping actual, tangible air from a actual, tangible, living, breathing human being's lungs into the contiguous space around you.  This is why measurements are at times so irrelevant.  The radio and the synth probably measured better than my amp.  But those who are addicted to DHTs - as I am - are in love with their tone, first and foremost.  Properly implemented they sound *live* and having spent far too much of my life at live concerts, this is what I crave.  I am willing to admit that this is entirely subjective - meaning this craving for the real - but a DHT amp's ability to get closer to the music is not subjective.  That is fact when you have a lot of experience with live music.  So tube warmth versus SS dynamism and detail is a bogus argument.  DHTs - as the 2A3 appears in the Stratus - has it all.  Said otherwise: who cares if an amp can *drive* a certain pair of headphoneif what is driven into it is a false simulacrum of an actual instrument? 
 
Aug 24, 2013 at 12:47 AM Post #1,097 of 4,456
*whew*
 
Glad my EC Leviathan won't be using those EP transformers. I might pick up a Stratus down the line to compare-should be fun!
 
Few EC Leviathan deets:
 
a) Paralleled DHTs
b) High frequency AC heater
c) Tango ITs
d) Direct coupling-no caps
e) Dual rectified external PS
f) Speakers!
 
Craig's 4x45 Levi proto:
hP1Uujg.jpg

 
The new 4x2a3 should be pretty similar.
 
Aug 24, 2013 at 2:15 AM Post #1,098 of 4,456
Well said, fejnomit! Wow... Stratus owners sure are some of most interesting reviewers around... Language used could be a bit flowery at time, but never fail to make a good read! Can't wait for my Stratus to arrive in Nov :)
 
Aug 24, 2013 at 5:13 AM Post #1,099 of 4,456
Quote:
 
Has he specified how much power it will deliver into the HE-6?
 
 
The Stratus can produce 1.8W (9.5Vrms) into a 50 ohm load like the HE-6.

 
Unfortunately the HE-6 has been measured at a very low 77db/mW,  you can do the math but I don't think that leaves much headroom?
I have seen no claims of any EC amp power into 50 ohms or any other DHT headphone amp for that matter..
 
The only SET that claims it can power the HE6 is the PSE EL34 AudioNote with its double C-core output transformers.
 
Quote:
On the topic of transformers, as Donald has noted, a transformer per se is not automatically a better thing.  They have to be the right transformer and that - for me at least - was the problem with the EC gear I owned and why, in the end, I sold both the ZD and the BA - tone.  , I determined was a result of the Electraprint transformers that Craig prefers.   

 
You can't really blame ElectraPrint,  he spec's 5k:16 ohm 50mA transformers.  So the Stratus is more powerful with a 2A3 into a 50 ohm headphone than the BA.
 
Aug 24, 2013 at 12:42 PM Post #1,100 of 4,456
Quote:
 
Unfortunately the HE-6 has been measured at a very low 77db/mW,  you can do the math but I don't think that leaves much headroom?
I have seen no claims of any EC amp power into 50 ohms or any other DHT headphone amp for that matter..
 
The only SET that claims it can power the HE6 is the PSE EL34 AudioNote with its double C-core output transformers.
 

 
 
At 77dB/1mW efficiency, 1.8W into them = 109.5dB max SPL. I've listened to the HE-6 with the Stratus and the amp had headroom to play them much louder than I care to listen. YMMV.
 
The ANK Audio Kits amp is a push-pull class A EL84 amp, for clarification.
 
Aug 24, 2013 at 3:30 PM Post #1,102 of 4,456
Quote:
Few EC Leviathan deets:
 
c) Tango ITs
d) Direct coupling-no caps

 
An amp which is direct coupled means there's no coupling cap or interstage transformer.
 
Quote:
Are we back to thinking volume=properly driven??
confused.gif

 
-Daniel

 
Whether something is properly driven or not is subjective. Catfish asked if there would be any headroom for the HE-6 with the Stratus, and I posted my calculation and listening experience. YMMV.
 
Aug 24, 2013 at 3:35 PM Post #1,103 of 4,456
Quote:
 
An amp which is direct coupled means there's no coupling cap or interstage transformer.
 
 
Whether something is properly driven or not is subjective. Catfish asked if there would be any headroom for the HE-6 with the Stratus, and I posted my calculation and listening experience. YMMV.

Guess that changed with the Tangos then-at least the Tango version 5 of us opted for. As for the HE-6, there will never be a consensus on that one. One group claims just pure, clean current is all that's needed, others say a minimum up 10-15 watts into 50 owns is the only way to truly hear them. Then there's the curveball of wildly varying efficiency ratings of HE-6s currently in production so...who knows. Trust your ears right? Seems most Stratus owners are talking about superb results with Sennheisers and Audezes-haven't seen too much HE-6 talk unfortunately.
 
-Daniel
 
Aug 24, 2013 at 10:05 PM Post #1,104 of 4,456
I agree the 6N1P is a more detailed sounding tube, and noticeably so even after burning in for awhile. I must have several hundred hours on mine. When I had RCA dual plates 2A3s installed, the 6N1P worked well adding a little detail. But when I installed the EML Meshplates I noticed the sound was a little harder. I switched to a Sylvania 6BQ7A and it smoothed things out just enough. Interestingly, the RCA 6BQ7A had sort of a scooped out sound in comparison to the Sylvania. I have played around with a few different tube set ups and, to my ears (T1 phones) I am happiest with EML Meshplate 2A3s, stock rectifier and Sylvania

I picked up a cheapo Sylvania 6BQ7A with grey plates. I, too, prefer the Sylvie to the RCA. Are yours black or grey plates?

My happiest tube set up currently is the EML Mesh 2A3, EML 5u4g, and Sylvania 6BQ7A with the LCD3.
 
Aug 25, 2013 at 2:32 AM Post #1,105 of 4,456
Quote:
You can't really blame ElectraPrint,  he spec's 5k:16 ohm 50mA transformers.

Catfish you missed my point entirely. EP comments had nothing to do with HE-6 comments.
 
Quote:
My happiest tube set up currently is the EML Mesh 2A3, EML 5u4g, and Sylvania 6BQ7A with the LCD3.

 
Dr. Headphone, Thank you for bringing this thread back to topic -- and that is indeed a VERY nice set-up!!
Something about the way the EMLs light up those LCD-3s, top to bottom.  The best I've ever heard them at least.
 
Aug 25, 2013 at 11:17 AM Post #1,106 of 4,456
Quote:
Quote:
Catfish you missed my point entirely. EP comments had nothing to do with HE-6 comments.
 
 
Dr. Headphone, Thank you for bringing this thread back to topic -- and that is indeed a VERY nice set-up!!
Something about the way the EMLs light up those LCD-3s, top to bottom.  The best I've ever heard them at least.

 
No I understand what you are saying has nothing to do with the HE-6,  not all electraprint transformers for 300b's are like those undersized 5k:16 50ma in the BA.  ElectraPrint can make a good transformer for a 300B/2A3 amp you just get what you pay for.  You were saying Jack's transformers aren't as good as others but he just supplies what the customer asks /pays for.  Check out his website he can make transformers that would suit a 300B much better.  That's all I'm saying.  Kind of like going to Ruth's Chris steakhouse and ordering a flank steak.
 
Aug 25, 2013 at 10:03 PM Post #1,107 of 4,456
drHeadphone, Thank you for bringing this thread back to topic -- and that is indeed a VERY nice set-up!!
Something about the way the EMLs light up those LCD-3s, top to bottom.  The best I've ever heard them at least.


I have a cryo'd RCA 6BQ7A and a Westinghouse 6BQ7A on the way. Should be a fun comparison between 6BQ7A's and cryo'd versus raw. Im also thinking hard on this cryo'd 6N1P-EV. Very expensive for such a tiny tube.
 
Aug 26, 2013 at 10:51 PM Post #1,109 of 4,456
No I understand what you are saying has nothing to do with the HE-6,  not all electraprint transformers for 300b's are like those undersized 5k:16 50ma in the BA.  ElectraPrint can make a good transformer for a 300B/2A3 amp you just get what you pay for.  You were saying Jack's transformers aren't as good as others but he just supplies what the customer asks /pays for.  Check out his website he can make transformers that would suit a 300B much better.  That's all I'm saying.  Kind of like going to Ruth's Chris steakhouse and ordering a flank steak.


From my experience, each transformer vendor seems to have a bit of a "house sound", intentional or not. I suspect this is due in part to the choice in winding geometry by the designer.
 
Aug 28, 2013 at 10:16 AM Post #1,110 of 4,456
Quote:
I have a cryo'd RCA 6BQ7A and a Westinghouse 6BQ7A on the way. Should be a fun comparison between 6BQ7A's and cryo'd versus raw. Im also thinking hard on this cryo'd 6N1P-EV. Very expensive for such a tiny tube.

 
Thanks for this "find" !
 
That cryo'd 6N1P-EV 1977 looks *very* interesting. I will be looking forward to your review comments.
 
Their description didn't mention one of the factory origins you have, but I am definitely a fan of deep cryo. That's one of the reasons the Jena cables can be magical.  
 

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