or Connect
Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › DNA Stratus 2A3 amplifier - first impressions
New Posts  All Forums:Forum Nav:

DNA Stratus 2A3 amplifier - first impressions - Page 35

post #511 of 2430
Quote:
Originally Posted by fejnomit View Post

I was looking at the F2J from the guy in Reno for about half the price of the J2...  Do you think that's too low?

 

Yes - speakers on head - like the K1000 in my opinion...

 

Anyway - I guess the part of my post where I said I've tried various SS speaker amps got lost.  I have tried a vintage Marantz rated at 100wpc; Blue Circle monoblocs rated at 50W; Audiozone Amp-1 rated at 45W; my old Yamaha integrated rated at 250W; and the speaker taps off my Marantz home theater amp, also rated at 250W.  I can understand what people are talking about.  And I respect all the homework that has been done by everyone on the HE-6 threads.  But this is the Stratus thread and - again - I was merely trying to answer whether I have listened to HE-6s on the Stratus and whether I liked the combination. Answer is still a resounding yes.  Never meant to imply it's the best combo ever.

Had the question been about the best amps to pair with the HE-6, I would have directed him to that thread.  You get the point...

 

Now, despite all that, none of my SS attempts have resulted in answering the treble issue I mentioned.  The Stratus did.  That's all.  That's also why I have been looking into the current source amps, since, as you point out, that is the real issue...

 

Anyway, onto bigger and better things:  curious if any Stratus owners have been listening to LCD-3s on it like I have?

 

 

Gotcha.....wink_face.gif

 

Mark is a good guy to deal with.  The F2J may work with all other headphones good as well.


Edited by preproman - 3/5/13 at 2:15pm
post #512 of 2430
Quote:
Originally Posted by fejnomit View Post

I was looking at the F2J from the guy in Reno for about half the price of the J2...  Do you think that's too low?

 

Yes - speakers on head - like the K1000 in my opinion...

 

Anyway - I guess the part of my post where I said I've tried various SS speaker amps got lost.  I have tried a vintage Marantz rated at 100wpc; Blue Circle monoblocs rated at 50W; Audiozone Amp-1 rated at 45W; my old Yamaha integrated rated at 250W; and the speaker taps off my Marantz home theater amp, also rated at 250W.  I can understand what people are talking about.  And I respect all the homework that has been done by everyone on the HE-6 threads.  But this is the Stratus thread and - again - I was merely trying to answer whether I have listened to HE-6s on the Stratus and whether I liked the combination. Answer is still a resounding yes.  Never meant to imply it's the best combo ever.

Had the question been about the best amps to pair with the HE-6, I would have directed him to that thread.  You get the point...

 

Now, despite all that, none of my SS attempts have resulted in answering the treble issue I mentioned.  The Stratus did.  That's all.  That's also why I have been looking into the current source amps, since, as you point out, that is the real issue...

 

Anyway, onto bigger and better things:  curious if any Stratus owners have been listening to LCD-3s on it like I have?

Regarding the LCD-3s, I haven't listened to the Stratus at all yet, but when it gets here (shortly) I will be. 

post #513 of 2430

One thing that I think is missing from these discussions-connecting the HE-6, K-1000, or any headphone with an impedance from 30+ ohms to 120 ohms directly to an amps speaker taps may not be giving you a 'flat' frequency response. The amp could be ok or it could even be oscillating which could cause the problems some people are experiencing in the highs. Virtue Audio states in the manual for the Sensation amps that speakers from 2-16 ohms can be used, but higher impedances may not have optimum frequency response. I have noticed on the amps I have used , both tube and SS, that connecting the HE-6 directly to the speaker taps doesn't always sound 'right'.

 

HiFiMan makes the HE-ADAPTER for this reason. With the HE-6 plugged into the Adapter and the Adapter speaker taps connected to the amp speaker taps, the amp is seeing a load of 9 ohms measured with a VOM. Now the amp is driving a load that is in the range it was designed to drive. However, the stock HE-ADAPTER is a somewhat nasty device in stock form. It uses ceramic resistors which don't sound good, so I upgraded mine to Mills and Riken resistors. From my experience with the Adapter I would recommend you try it or something similar on your amp before making a final judgment on the HE-6.

 

Go to 6 Moons and look up his review of the K-1000 with Norh and Antique Sound Labs amps some years ago. He actually experienced gross oscillation with the Antique amp and I confirmed this with the exact same amp I owned at that time. The Norh amp was fine and sounded good with the K-1000 and was one of the recommended amps for these phones at the time. This shows how the higher impedance of a headphone may or may not affect the amp that is driving it. Hope this helps. 

post #514 of 2430

1000

 

 

1000

 

 

 

Quote:

 

Originally Posted by Da5Id View Post

OK thanks I feel better now. :-) My OCD was kicking in pretty hard there for a while. 

A couple of pics from earlier in the thread to "help" with the wait!

post #515 of 2430
Quote:
Originally Posted by third_eye View Post

A couple of pics from earlier in the thread to "help" with the wait!

These don't really help ...    These can actually make the wait even more unbearable, at least for me, when I stared at these pics while waiting for my Stratus biggrin.gif


Edited by econparanoia - 3/5/13 at 9:05pm
post #516 of 2430

I'm a former Stratus owner, and listened fairly exclusively with my LCD3. What a great combo!

 

But IMO the 3's sounded poor without the tube upgrade. Popping in the SE Princesses or EML solids made a dramatic difference to my LCD3 experience.

post #517 of 2430
Quote:
Originally Posted by Duckman View Post

I'm a former Stratus owner, and listened fairly exclusively with my LCD3. What a great combo!

 

But IMO the 3's sounded poor without the tube upgrade. Popping in the SE Princesses or EML solids made a dramatic difference to my LCD3 experience.

Hey Duckman ;)

 

I love the lcd-3 - stratus combo as well. =)   Thanks for selling me your amp!  

 

Can anyone please fill me in on the best rectifier tube to use with the stratus?  I am currently using sophia princess 2a3's and an old school RCA rectifier tube.  I have heard that the EML rectifier might be the way to go..

 

cheers,

 

gav.

post #518 of 2430

he HE-6's don't require as much current as you think,  the hifiman adapter just dumps current  the ground,  its voltage that's needed and why high power SS amps are popular.   5W into 50 ohms is 20+Vp-p which is  equivilant to a solid 35 watts into 8 ohms (most solid state amps are over-rated). 

 

A 3 watt watt tube amp with a 50 ohm secondary has a chance,  see audionotes new HE-6 tube amp.  Possibly the maker of the Stratus could offer a 50 ohm secondary for the HE-6. 

post #519 of 2430
Quote:
Originally Posted by catfish View Post

he HE-6's don't require as much current as you think,  the hifiman adapter just dumps current  the ground,  its voltage that's needed and why high power SS amps are popular.   5W into 50 ohms is 20+Vp-p which is  equivilant to a solid 35 watts into 8 ohms (most solid state amps are over-rated). 

 

A 3 watt watt tube amp with a 50 ohm secondary has a chance,  see audionotes new HE-6 tube amp.  Possibly the maker of the Stratus could offer a 50 ohm secondary for the HE-6. 

 

Donald -- is that easy enough to do? Could you offer that as an option? And would that impact performance for other headphones like the HD800? Sorry for asking basic questions. Electronics = magic in my head. blink.gif


Edited by Cante Ista - 3/6/13 at 6:28am
post #520 of 2430
Thread Starter 
Quote:
Originally Posted by ChrisB7605 View Post

Bud - i noticed earlier in the thread that u liked the stratus/he6 combo once the 6s are broken in... do u still use this combo? or mainly stick with the 800s?

 

Sorry for the "wait". I use my HD800 with the Sophia Princess 2A3s and a Kuhltube NOS 5U4G. I've read here about the 274B rectifier and wondered about buying the Sophia model. Anyone tried that?

 

I'm still upgrading cables. Right now I'm trying an Entreq Apollo 2012 i/c and a DHC silver Complement headphone cable. They both seem to provide a wide open window. I have the new Shunyata Anaconda from TCC to compare next, and I've also heard good things about the SAA HD800 upgrades.

 

The Stratus is quite amazing, because it continues to transcend the best complementary components. Absolute no noise background, gorgeous timbre and presence, macro and microdynamics, and utter realism.

 

Oops, we've been accused of being "fanboys"? Well, let's just say I like what I hear. haha

 

WRT the HE-6, I thought it sounded fine with the Stratus, though using it on the speaker terminals of the ss Odyssey Cyclops 100wpc provided tighter bass and overall better control.

 

I just received the HE-adapter to use with the HE-6, but I haven't tried it yet. Thanks to dpump for the tip on upgrading the resistors!

 

EDIT -- and a big THANK YOU to third_eye for the lovely photos!!!


Edited by budx3385 - 3/6/13 at 9:16am
post #521 of 2430
Quote:
Originally Posted by econparanoia View Post

These don't really help ...    These can actually make the wait even more unbearable, at least for me, when I stared at these pics while waiting for my Stratus biggrin.gif


haha, sorry.tongue.gif

post #522 of 2430
Quote:
Originally Posted by budx3385 View Post

 

Sorry for the "wait". I use my HD800 with the Sophia Princess 2A3s and a Kuhltube NOS 5U4G. I've read here about the 274B rectifier and wondered about buying the Sophia model. Anyone tried that?

 

I'm still upgrading cables. Right now I'm trying an Entreq Apollo 2012 i/c and a DHC silver Complement headphone cable. They both seem to provide a wide open window. I have the new Shunyata Anaconda from TCC to compare next, and I've also heard good things about the SAA HD800 upgrades.

 

The Stratus is quite amazing, because it continues to transcend the best complementary components. Absolute no noise background, gorgeous timbre and presence, macro and microdynamics, and utter realism.

 

Oops, we've been accused of being "fanboys"? Well, let's just say I like what I hear. haha

 

WRT the HE-6, I thought it sounded fine with the Stratus, though using it on the speaker terminals of the ss Odyssey Cyclops 100wpc provided tighter bass and overall better control.

 

I just received the HE-adapter to use with the HE-6, but I haven't tried it yet. Thanks to dpump for the tip on upgrading the resistors!

 

EDIT -- and a big THANK YOU to third_eye for the lovely photos!!!

 

My pleasure Bud! Thank you for your contributions and impressions in this thread. They helped me seek out the audition with Donald and also in my choice of tube upgrades.

post #523 of 2430

I just ordered some 6BQ7As, 6N1P-EVs, and RCA 5U4G ST from eBay. Although these tubes are claimed to be "tested good" by fine rated sellers, I am still somewhat concerned about whether it is safe to try tubes on the Stratus without testing them by myself using a tube tester. However, I don't current own a tube tester.

 

What do you guys think? Do you own a tube tester? And, is there any (rule of thumb) eyeball test that can be done? I am also wondering if the Stratus has some built in protection mechanism against malfunctioned (such as shorts in tubes) or incompatible tubes.

 

In addition, as a more specific question, is the RCA 5U4G ST compatible with the Stratus? Specification wise, are they identical to a regular 5U4G?  

 

 

post #524 of 2430
Quote:

I just ordered some 6BQ7As, 6N1P-EVs, and RCA 5U4G ST from eBay. Although these tubes are claimed to be "tested good" by fine rated sellers, I am still somewhat concerned about whether it is safe to try tubes on the Stratus without testing them by myself using a tube tester. However, I don't current own a tube tester.

 

What do you guys think? Do you own a tube tester? And, is there any (rule of thumb) eyeball test that can be done? I am also wondering if the Stratus has some built in protection mechanism against malfunctioned (such as shorts in tubes) or incompatible tubes.

 

In addition, as a more specific question, is the RCA 5U4G ST compatible with the Stratus? Specification wise, are they identical to a regular 5U4G? 

 

To my knowledge, ST merely refers to the coke bottle shape of the tube.  If it's a 5U4G then it's completely drop-in. 

 

My rule of thumb on the fleabay is to only order tubes from a place I know or that have been tested and THE RESULTS POSTED.  You never know what you're going to get when it says "tested good" or even "tested 100%."  If they know what they are doing then they will post the results for each triode or section so you know that you are getting internally matching tubes as well - very important.  If they don't post that, then I figure they're amateurs or they're hiding something and preying on amateurs. 

 

In terms of safety, unless you have a tester I think there's little you can do to be 100% sure.  In the case of a driver or output tube, things wouldn't be so bad - the amp just wouldn't work.  The rectifier is the one you need to watch out for.  I blew two rip-off rectifiers in my BA and nearly blitzed one of my ears...

post #525 of 2430
Quote:
Originally Posted by fejnomit View Post

 

To my knowledge, ST merely refers to the coke bottle shape of the tube.  If it's a 5U4G then it's completely drop-in. 

 

My rule of thumb on the fleabay is to only order tubes from a place I know or that have been tested and THE RESULTS POSTED.  You never know what you're going to get when it says "tested good" or even "tested 100%."  If they know what they are doing then they will post the results for each triode or section so you know that you are getting internally matching tubes as well - very important.  If they don't post that, then I figure they're amateurs or they're hiding something and preying on amateurs. 

 

In terms of safety, unless you have a tester I think there's little you can do to be 100% sure.  In the case of a driver or output tube, things wouldn't be so bad - the amp just wouldn't work.  The rectifier is the one you need to watch out for.  I blew two rip-off rectifiers in my BA and nearly blitzed one of my ears...

Thank you, fejnomit, for the helpful input.

 

I was mainly worried about safety of the equipments, in this case the stratus and the DAC connected to it. I didn't think about personal safety...  Now I am thinking a tube tester is probably in order...

 

One of the two 5U4G tubes I bought has a brief testing result says, merely,  "RCA 5U4G ST Shape Good Used Pull. Decent Lettering Tests 56/40 And 56/40 on Calibrated TV7 So Very Nicely Balanced." Does this qualified as "the results" you talked about? Or should I look at tubes with a more detailed testing result?   

 
The other 5U4G was just advertised as "HERE IS AN RCA 5U4G RECTIFIER TUBE. THIS HAS A COKE BOTTLE SHAPED GLASS AND LARGE BLACK PLATES. THIS TUBE TESTS EXCELLENT ON BOTH SECTIONS FOR EMISSION AND SHORTS. DATE CODE IS 448." Now I'm not sure if I should even try it when I receive it, or just skip it.
 
Do you think small driver tubes like the 6QB7A and 6N1P are what we can be LESS worried about? I bought the 6N1P from a Russian seller, who listed very detailed testing results. I get several 6QB7As pretty cheap, at around $3 each plus shipping. The seller of the 6QB7As did not list any test results, but seemed to have an abundant stock of these tubes. 
 
Sorry for bringing up all these details. But I think these questions are perhaps of interest to Stratus owners like me who are not experienced with tubes, and who seek for insights from veterans like fejnomit, third_eye, Budx, and, of course, Donald himself.

Edited by econparanoia - 3/6/13 at 7:27pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: High-end Audio Forum
Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › DNA Stratus 2A3 amplifier - first impressions