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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 126

post #1876 of 7003
Quote:
Originally Posted by mordy View Post

Let's try this:

 

Go to the Ebay ad again, and look at the pictures. On the left is a slider; pull it down, and there is one more picture there. Using the CTRL button and the scroll wheel on the mouse, blow up the picture. Then use the Mouse Here To Zoom In feature and look carefully at the getter. IMHO it is a circular getter. (The third picture blown up also supports this.) The ribbing of the plate looks like the Siemens tube.

 

If this indeed is it, we have a cheap supply of ersatz Siemens tubes....
 

A slider? Mouse Here to zoom in feature? a mouse CTRL button? Not on my Win7 PC... Perhaps you have something different....

 

Anyway, in the fifth picture, I think I see a saucer getter, but due to reflections in the glass, I am not sure..... 

post #1877 of 7003

I'm definitely seeing a saucer getter on at least one of these pictures. And regardless, the shiny & pointy pins -and everything else- just screams Eastern German/Eastern European/Russian origin... These tubes aren't West German at any rate.

 

Doesn't mean they're bad tubes though. If someone wants to get 10 or 20 of these and dispatch them to everyone around here, I'd be more than willing to get a pair... I won't shed $26 on blind -Russian- faith though...

post #1878 of 7003
Quote:
Originally Posted by Audiofanboy View Post

I'm definitely seeing a saucer getter on at least one of these pictures. And regardless, the shiny & pointy pins -and everything else- just screams Eastern German/Eastern European/Russian origin...

Absolutely. In fact, the symbol of the manufacturer, the Oktyabr factory in Vinnytsia, Ukraine, is visible on the tube and on that piece of paper.
post #1879 of 7003

im expecting 10 of these any day now had bought the ones on mordy's picture for $26.00 on Ebay but saw the same elsewhere in Bulgaria i think for $15.00 so canceled the original order

Processed By eBay with ImageMagick, R1.1.1.M2b


Edited by MIKELAP - 7/11/13 at 5:23pm
post #1880 of 7003

Heptode overload?

 

Looks like we have two Russian heptodes available, both 6A2A. The one with the C around the designation is made by Svetlana, which is a very reputable manufacturer.

 

The second type is labeled Elektronorgtecnika and made in the Octyabr (October) factory in Ukraine. (Apparently Russia and Ukraine are two different countries according to the cognoscenti, so forgive me if I call both Russian tubes.)

 

AFB, I can understand your frustration in ferreting out the best sounding heptodes since there are so many settings to try - EF95 NS (no strap), EF95 1-7 strap, EF95 2-7 strap, EF92 NS. And then the observation that it may take 50 hours of burn in to get to hear the true nature of the tube. And then that they all sound good, which in itself is not a bad thing. However, this makes it so much harder to pick winners.

 

Don't understand why you seem to be hesitant about Russian heptodes. After all, all the driver tubes for the LD MKIII/IV are Russian made. I seem to remember that the Svetlana 6A2A did not seem to impress in one review. However, maybe we have to reserve judgment until the tubes have been tried for more than 50 hours.

 

In general, we are all very grateful for all your painstaking research and efforts - thanks!

post #1881 of 7003
Quote:
Originally Posted by mordy View Post

Don't understand why you seem to be hesitant about Russian heptodes. After all, all the driver tubes for the LD MKIII/IV are Russian made. I seem to remember that the Svetlana 6A2A did not seem to impress in one review. However, maybe we have to reserve judgment until the tubes have been tried for more than 50 hours.

 

While I can't speak for AFB, I can tell you why I am hesitant about these tubes.... You might remember, I bought some Russian 6J4P/6AU6 (page 62 - see here), and they were very poor quality. Since then, my thinking is only "premium" Russian tubes from now on, that is, tubes with the -e, -ev or similar suffix, like the Voshods 6zh1p-ev, for example. Searching for 6A2P-e and 6A2P-v comes up empty.....

 

But of course, if others in this forum are willing to give them a chance and then report that these 6A2P are excellent, I will pounce on them! lol

post #1882 of 7003

I never said I didn't want to buy Russian or Eastern European tubes, but, in a way, yes, I would be quite careful about those tubes, and wouldn't just blindly stick them in my amp without a bit of information.

 

Like gibosi said, tube quality varied quite a bit in Eastern production, and while the best and most rugged ones are clearly top-tier -I paid quite a bit to get some genuine DR power tubes and I can vouch for those types being almost god-tier- whether mil-spec or just very good civilian tubes, many of the more basic ones can show wide variations. Even -E or -EV tubes aren't always that good and have widely different quality control depending on year and factory...

 

Speaking of variations, -and that's actually my main concern over money and sound quality- many Soviet or Eastern tubes, while close, weren't exactly made to the same specs as their Western equivalents (slightly different tubes, basically), so you never really know what you're getting. They're exactly that: equivalents. Some tube type are very close or identical in specs like the 6AK5 and 6ZH1P, others are much further apart like the 6N23P and other common double triodes. Will they work? Probably, but I do like to know what I putting in my amp, just in case...

 

Again, I'd be more than willing to shed a few bucks for some interesting Ukrainian tubes or other, but the last couple of times I went for one of those "10 or 20 tubes for peanuts" deal, it turned out to have been a bad idea, every time... And the last time, it was -E tubes too!

post #1883 of 7003

http://www.ebay.com/itm/6A2P-6BE6-EK90-Heptode-Tubes-5pcs-in-BOX-NOS-1980s-/350748093273?pt=Vintage_Electronics_R2&hash=item51aa372b59

 

These Elektronorgtecnika 6A2P tubes from 1986 definitively have saucer type getters, but the plates are not ribbed like the previous post of these tubes.
 

post #1884 of 7003

I have received a few more triodes recently, so off to triode land I go... :)

 

These Philips Miniwatt CV452 are actually 6AT6 which are very similar to the 6AV6. They were manufactured in the 1950s by Philips in their Heerlen, Holland factory, so these likely were also sold under the Amperex/Bugleboy brand as well.

 

 

1950's Lorenz, identical to AFB's (page 102)

 

 

1970's Telefunken, identical to AFB's (also page 102)

 

 

And finally, Tungsram EBC91/6AV6, manufactured in Hungary. With O-getters and rather new-looking boxes I have the impression that these are not that old. And from this pdf, the "w" printed on the glass might suggest 1982, but who knows?

 

 

 

Since I already have some Mullard EBC91, I now realize that I have managed to collect another example of the so-called  "British - Holland - German sound continuum", with Hungary thrown in for good measure! lol

 

And of course, even though I am now back in triode land, I will continue to follow with great interest all the wonderful news from heptode land. :)

post #1885 of 7003

We're all expecting some major European double diode-triode shootout now gibosi; your ears may not make it though four different pairs of triodes lol!

 

Just fyi, if anyone's interested, I still have an extra pair of the Philips CV452 (I have a lot of extra pairs of a lot of tube types actually...).

post #1886 of 7003

What are pins of 80's Voshkod ef95 tubes covered with, silver, platinum, nickel?

post #1887 of 7003
Quote:
Originally Posted by MIKELAP View Post

im expecting 10 of these any day now had bought the ones on mordy's picture for $26.00 on Ebay but saw the same elsewhere in Bulgaria i think for $15.00 so canceled the original order

Processed By eBay with ImageMagick, R1.1.1.M2b

 

Hi mikelap.

 

This Siemens EK90 saga is developing into one of real Nordic proportions...I say this because, along with other factors, I would swear that mine (and therefore A11's) are one and the same as the tube shown here in the photo : pins; internal copper wire; saucer getter, and SMOOTH silver/grey plate. I have 2 pairs - one with clear bottom and one with black - the latter mentioned by A11, just to confuse matters even more...

 

To add to the confusion, I have noticed OTHER  Svetlana 6A2Ps that have slight ribbing on the plate...which I think are the ones you have ordered mikelap...

 

The internal construction of these Svetlanas certainly does appear superior to the other make(s) that are on the web.

So the plot thickens...

 

Now onto the sound that comes from my 'Siemens', whoever actually made them...

 

To strap or not to strap? This really is becoming another source of confusion (for me anyway). After finding that further burn-in with 1-7 tamed the initial 'shock' factor, I returned to non-strap and was pleased to find that Acapella 11's comparison on page 109 seemed absolutely on the ball - what really hit me straight away was a more open/airy sound, bordering almost on 'thin', compared to 'lush/heavy' 1-7 (I leave the proper terminology to A11!!). I would simply summarise the overall effect - for me - as more 'polite/refined' non-strapped, but more 'exciting' strapped.

Which do I prefer? Damned if I can yet be sure!! I think this debate could go on forever...

 

I envy you M that you came to your own conclusion so quickly...if only I could!

post #1888 of 7003
Quote:
Originally Posted by hypnos1 View Post

 

Hi mikelap.

 

This Siemens EK90 saga is developing into one of real Nordic proportions...I say this because, along with other factors, I would swear that mine (and therefore A11's) are one and the same as the tube shown here in the photo : pins; internal copper wire; saucer getter, and SMOOTH silver/grey plate. I have 2 pairs - one with clear bottom and one with black - the latter mentioned by A11, just to confuse matters even more...

 

To add to the confusion, I have noticed OTHER  Svetlana 6A2Ps that have slight ribbing on the plate...which I think are the ones you have ordered mikelap...

 

The internal construction of these Svetlanas certainly does appear superior to the other make(s) that are on the web.

So the plot thickens...

 

Now onto the sound that comes from my 'Siemens', whoever actually made them...

 

To strap or not to strap? This really is becoming another source of confusion (for me anyway). After finding that further burn-in with 1-7 tamed the initial 'shock' factor, I returned to non-strap and was pleased to find that Acapella 11's comparison on page 109 seemed absolutely on the ball - what really hit me straight away was a more open/airy sound, bordering almost on 'thin', compared to 'lush/heavy' 1-7 (I leave the proper terminology to A11!!). I would simply summarise the overall effect - for me - as more 'polite/refined' non-strapped, but more 'exciting' strapped.

Which do I prefer? Damned if I can yet be sure!! I think this debate could go on forever...

 

I envy you M that you came to your own conclusion so quickly...if only I could!

 

I personally really like the 7-1 strap on the HD650, but with my Pro900 its way too sibilant. To me that setting just adds a lot of high en detail, which can be fatiguing on already sibilant cans like Ultrasones. I haven't tried with my T70 yet but they are also bright out of the box and would probably feel the same way.

post #1889 of 7003

Hi sssboa,

 

Somewhere in the back of my mind I think I remember reading that the pins on some Russian tubes were coated with rhodium which does not oxidize, but cannot remember the source. Rhodium is a member of the platinum family and often used in corrosion and heat resistant applications.

 

AFB - what do you think?
 

post #1890 of 7003
Quote:
Originally Posted by sssboa View Post

What are pins of 80's Voshkod ef95 tubes covered with, silver, platinum, nickel?

 

Quote:
Originally Posted by mordy View Post

Hi sssboa,

 

Somewhere in the back of my mind I think I remember reading that the pins on some Russian tubes were coated with rhodium which does not oxidize, but cannot remember the source. Rhodium is a member of the platinum family and often used in corrosion and heat resistant applications.

 

AFB - what do you think?
 


Yup Mordy, you were faster than me to answer! All those tubes have rhodium-coated pins, from what I read about a year ago when I was investigating tubes manufactured in the USSR. Basically, all those pointy -Russian or Eastern- pins all look the same and have the same shine, so I would be pretty sure that they all have the same standard coating.

 

Think of rhodium as being about as good as gold in terms of plating qualities, i.e. resistance to corrosion and good conductivity. I remember my -since then sold- HD650 DIY connectors being also rhodium plated; just a random hi-fi-ish example. Gold being more "fashionable", we don't actually get to see many "rhodium plated" cables or anything that often though...

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