[budx3385]

I waited several weeks for them, but I like using the Duende dampers very much on my WE275s. They add a firmness and increase the sense of presence, of coherent realism, without any deleterious spectral effects that I have detected.
 
Tapping the case of my Stratus causes a zing with most 2A3 tubes, but the dampers dull this effect. Firmly.
 
They must be engaged carefully, and they fit on the very top tightly - yup, firmly. 

 
Herbie's are good, too, and there are others that I haven't tried. Of course, YMMV. 

 

[auricgoldfinger]

  I waited several weeks for them, but I like using the Duende dampers very much on my WE275s. They add a firmness and increase the sense of presence, of coherent realism, without any deleterious spectral effects that I have detected.
 
Tapping the case of my Stratus causes a zing with most 2A3 tubes, but the dampers dull this effect. Firmly.
 
They must be engaged carefully, and they fit on the very top tightly - yup, firmly. 

 
Herbie's are good, too, and there are others that I haven't tried. Of course, YMMV. 

 
Who is Herbie?

 

[budx3385]

http://herbiesaudiolab.net/teflon.htm

 

[ShinRA88]

When people talk about 275 tube in this thread, are they talking about the original WE275A or the replica made by PSVANE?

 

[bigfatpaulie]

  When people talk about 275 tube in this thread, are they talking about the original WE275A or the replica made by PSVANE?

 
Replica.  At least I can't recall anyone with originals. 

 

[auricgoldfinger]

The WE275A is a 5V tube that won't work with the Stratus.

 

[ShinRA88]

Thanks, I got confused because AFAIK 275A has a different spec than  2A3. But last time I heard, QC of PSVANE tubes are bad, but is it no longer the case?

 

[stuart1927]

I dug out my Western electric 1575 tube tester today and tested my growing collection of 2a3 tubes.
 
As expected, the Kr audio tube that crapped out on me is indeed showing nothing on the scale and is indicating a dead tube.
 
I tested my remaining three KR audio tubes and all are showing pretty low on the micromhos scale....about 1400 v's a spec value of 1800.
 
My Nos tubes (GE dual mono plates and 2c4c's by svetlana) all show much stronger...2400-2800 micromhos.
 
My sophia 2a3 globe mesh plates read fairly low also, one is 1400 and the other 1800.
 
This has me wondering if the sophia's are up to scratch. They sound fine, but the variance is pretty large, with one just on spec and the other low. Normally, you'd expect a new tube to show significantly greater than min values, at least that's what I've found before.
 
The Nos tubes are all reading much greater than min value.
 
Anyone here have any insights on why the KR audio and Sophias are reading so much lower than Nos tubes?
 
sbb

 

[eserafinojr]

Stuart,
 
Although I don't own a DNA Stratus, I do have a large tube collection and 2A3s in particular and can shed some light on that. I use 2A3s in a custom SET Power Amp I own.
 
I too have a pair of KR 2A3s and although they sound fine (Not as good as NOS tubes IMHO) they test lower on all 4 of my tube testers as well.
 
The boutique re-issue tubes from guys like KR are not perfect 2A3 electrical equivalents. They are similar but not the same. Their electrical specifications are not a 1:1 copy, but they are similar.
 
Their brand new Gm rating is lower than what a vintage 2A3 spec is. So testing one of those 2A3s expecting NOS 2A3 readings on a tester will never happen, it will always be a little lower.
 
I wouldn't be terribly concerned as the vintage 2A3 tube test for a re-issue 2A3 because of the aforementioned reasons will show a tube that appears weak but is not.
 
FWIW my favorite 2A3s are the Mono Plates from TS, RCA and Arcturus. Second being the very early "Dual Plate" 2A3s with the Mono Plate style filament top springs, those are even more rare than the Mono Plates and sound just as good. Honorable mention for "Dual Mono PLate" 2A3s as well.
 
Hoping to hear a Stratus one day. After I sold my WA22 I almost bought one but ended up buying a custom ordered LD MK6+ SE with factory upgraded components and I'm enjoying it more than my 22.

 

[bigfatpaulie]

Also, keep in mind that new tubes are made very differently with very different materials than their vintage counterparts.  Things like lead and mercury aren't as readily available and are controlled in their use now versus back then.

 

[stuart1927]

Interesting guys...thanks! I've been collecting a few nos 2a3s so never really appreciated that the new tubes would be electrically different.

Had quite an extensive re-listen to the GE dual mono plates last night. I keep coming back to these tubes...they sound particularly great with orchestral music. On re-evaluation, they out perform the kr audio and Sophia tubes for this genre. I will see how other types of music compare tonight!

Still haven't seen these tubes anywhere else....pretty rare I think.

Sbb

 

[auricgoldfinger]

@eserafinojr and @bigfatpaulie thanks for your explanation.  Very interesting.
 
 

 

[stuart1927]

  Stuart,
 
Although I don't own a DNA Stratus, I do have a large tube collection and 2A3s in particular and can shed some light on that. I use 2A3s in a custom SET Power Amp I own.
 
I too have a pair of KR 2A3s and although they sound fine (Not as good as NOS tubes IMHO) they test lower on all 4 of my tube testers as well.
 
The boutique re-issue tubes from guys like KR are not perfect 2A3 electrical equivalents. They are similar but not the same. Their electrical specifications are not a 1:1 copy, but they are similar.
 
Their brand new Gm rating is lower than what a vintage 2A3 spec is. So testing one of those 2A3s expecting NOS 2A3 readings on a tester will never happen, it will always be a little lower.
 
I wouldn't be terribly concerned as the vintage 2A3 tube test for a re-issue 2A3 because of the aforementioned reasons will show a tube that appears weak but is not.
 
FWIW my favorite 2A3s are the Mono Plates from TS, RCA and Arcturus. Second being the very early "Dual Plate" 2A3s with the Mono Plate style filament top springs, those are even more rare than the Mono Plates and sound just as good. Honorable mention for "Dual Mono PLate" 2A3s as well.
 
Hoping to hear a Stratus one day. After I sold my WA22 I almost bought one but ended up buying a custom ordered LD MK6+ SE with factory upgraded components and I'm enjoying it more than my 22.

The only other strange thing is that the stock chinese 2a3B tubes with the Stratus, actually test similar to the Nos tubes (i.e. Micromhors in very similar range 2400-2800). You would think as these are new tubes and fairly cheaply produced (presumably not using the best of the best materials) that these would not test as high...and would be similar to other new tubes? Just when I thought I got it!

 

[stuart1927]

Well....I now swapped in the Nos Svetlana 2c4c's and reverted back to my U52 rectifier and Westinghouse driver. This might be my new favourite set up.
 
I got a new cable for my HD800's (Norne audio solvx) a while ago, and hadn't listened to my older Nos tubes with this cable. I think this may be part of the enhancement.
 
The Svetlana's have a real bass depth that was missing (just a touch) on the KR audio's and Sophia mesh plates. The detail, mids, and high's are still there, but the bass is definitely much better than I remember. It's a really nice match with the HD800's. They are perhaps a little more lively than the newer tubes...a bit more forward and seem to have a higher audible output. I've needed to dial back the volume a little. I don't know if this is just my imagination, but tracks that I would normally listen to at 3-3.5, I've needed to dial back to around 2 to 2.5. 
 
 
I've never agreed that the HD800 is bass shy, It's just accurate imho.....but the right tubes (and maybe cable) can give them just a touch more warmth that some people may need. 
 
The Svetlana's don't seem to glow at all, which is a shame, but they really sound fantastic. I've been listening to some other musical styles today, some jazz/ fusion, instrumental as well as some pop and I'm really liking the sound signature of these tubes. They play well with everything I've listened to so far.
 
For me this is one of the great things about the Stratus, there are so many combinations of tubes that can subtely change the sound signature. That might irritate some people, but for me it allows a lot of customisation and tayloring. I think I'm going to start taking notes though...so I don't forget what I've learned!
 
sbb

 

[Frihed89]

Tomorrow us Singapore head-fier's (myself and Froger and another Friend) will be having an amp-off, we'll be testing:

DNA Stratus
EC Studio
Apex Teton
Apex Sangaku
Woo WA5
Glenn EL3N
ECP L2
Ear Yoshino v12

All driven by the Chord Dave, via either the MicroRendu or Rednet 3 (we'll just pick one).

Probably will be using HE1000v2, LFF Code-X, Utopia for cans. Given what I've read about the Stratus I wouldn't be surprised if Froger enjoys the Ear Yoshino the most from that group, but I guess we'll see. Look forward to hearing the Stratus for the first time!

A short reply to the remarks about this "shoot-out":  $7+K sounds about right for a fantastic headphone amplifier, paired with the right tubes and headphones.  The "winner" was the Eddie Current Studio amp., the construction of which I know nothing about. The only thing I would caution on this amplifier is the paralleling of the output tubes.  If a single tube is not well balanced with the other in either channel, it will drag the other one down and eventually you will have to replace the pair.  I'm not sure if a balance pot in each channel will accomplish this.  
 
I agree wholeheartedly with the comment that the Stratus sounds very neutral.
 
One can replace some components (the coupling caps, electrolytics and resistors) and get a discernibly smoother analog sound, although that is a general overall impression, which is what i listen for instead of the "parts" of the whole sound.  One could try the top of the line Audio Note Silver foil and electrolytic caps and resistors (actually, try nothing less).  Mine were installed selectively by an Audio Note technician at my local AN shop.  Another idea would be to rip out all the old wire and internal cabling and replace it with it AN's best silver wire and cable, but I have not had this done, because the estimated time and effort to do all the soldering, plus the cost of cabling and wire, was quite high and my conventional headphones might not pick up any differences.  Adding just the coupling caps I spoke about made the biggest difference, as I did that first, at least a year before the other modifications.
 
A Stelaris will undoubtedly sound even better with the right headphones and I guess will put you in the $7K+ range.
 
For the average Joe, a reasonably priced OTL would always be my first pick, but there are so many of them out there, I can't comment on which one, except the old ZOTL and my "safety-fied" MPX3-something or other.