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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 134

post #1996 of 7298
Quote:
Originally Posted by mordy View Post

Hi A11,

 

 

From post 1858:

 

"I have saved the Russian 6A2P pictures and a surprise for later."

 

Did not hear about the surprise yet - did I miss something?

 

BTW, on your excellent chart, which I refer to every day, why don't you add the EF95 + 6/7 socket wire modification = EF92 setting for those of us who hate to change the jumpers underneath the LD MKIII?

 

Also, if you could change the spacing between the columns so that the first three columns have more space between them for clarity. (Or could it be my computer that bunches the three first columns too close?)
 

Did someone say a surprise i love surprises !

post #1997 of 7298

Hi Hypnos1, Apparently my Svetlana 6A2Ps do not have the ribbing , they are plain dark grey, which is almost unique between my tubes. It is like anthracite. I will take some shots later. But talking about it, I think I found a tube, which reflects this anthracite and smooth plate 6A2P (10/1967). It is a recent purchase, a Lorenz EK90 tube from Germany Army stocks (box dates to 1972)! Isn't that crazy. They look absolutely identical and sonic similarity is given. I need to hear them more in order to be able to also confirm sonic identity.

Oh, after more (comparative) listing to the Siemens EH90 tubes, my appreciation for them increased and they are in good competition with my Siemens EK90. They are not of your SH-logo and flat plate type, which I have just ordered. A pic is here and they look like the ones Mikelap has.

 

Hi Mordy, Woot, you actually kept it in mind. Well, no, you did not miss anything but indeed there will be little surprise when I come around writing it up. I would like to first sort out my current heptodes. The EF91/92 6-7 strap mod in EF95 setting has actually been in the table almost since the beginning. It is the last picture before the update notes. I agree, the formatting was not optimal and is updated now as well as a few minor other details.
 


Edited by Acapella11 - 7/18/13 at 4:53pm
post #1998 of 7298
Quote:
Originally Posted by Acapella11 View Post

Hi Hypnos1, Apparently my Svetlana 6A2Ps do not have the ribbing , they are plain dark grey, which is almost unique between my tubes. It is like anthracite. I will take some shots later. But talking about it, I think I found a tube, which reflects this anthracite and smooth plate 6A2P (10/1967). It is a recent purchase, a Lorenz EK90 tube from Germany Army stocks (box dates to 1972)! Isn't that crazy. They look absolutely identical and sonic similarity is given. I need to hear them more in order to be able to also confirm sonic identity.

Oh, after more (comparative) listing to the Siemens EH90 tubes, my appreciation for them increased and they are in good competition with my Siemens EK90. They are not of your SH-logo and flat plate type, which I have just ordered. A pic is here and they look like the ones Mikelap has.

 

Hi Mordy, Woot, you actually kept it in mind. Well, no, you did not miss anything but indeed there will be little surprise when I come around writing it up. I would like to first sort out my current heptodes. The EF91/92 6-7 strap mod in EF95 setting has actually been in the table almost since the beginning. It is the last picture before the update notes. I agree, the formatting was not optimal and is updated now as well as a few minor other details.
 

Thanks for the update always appreciated .

post #1999 of 7298

I just realized my stock tubes that came with the LD MKIII I think is the Sylvania 5654, it shows JHS 5654. Made in USA and also faded letters but I can make out "VAN_A" So i'm assuming it's Sylvania instead of the GE5654 though it has green letterings. And the only code I can make out is 308 which is inscribed from top to bottom.

 

Anyone can help me identify this?

post #2000 of 7298

JHS is a code used by Sylvania. As for the 308 a semi educated guess would be that the first digit stands for the year and the second and third represent the week of manufacture. Thus it could mean the 8th week 1973/(1963).
 

post #2001 of 7298

Which is quite interesting since I thought LD MKIII only came with GE5654 hmm...

post #2002 of 7298

Brief update for the Svetlana 6A2P and Lorenz EK90. OK, they are not perfectly identical. The saucer getters are differently constructed between them. Else, they are pretty much the same from the outside.

 

post #2003 of 7298
Quote:
Originally Posted by Acapella11 View Post

Brief update for the Svetlana 6A2P and Lorenz EK90. OK, they are not perfectly identical. The saucer getters are differently constructed between them. Else, they are pretty much the same from the outside.

 

 

The Lorenz are very nice, very similar to the Telefunken EK90.

post #2004 of 7298
European EBC90/EBC91 triodes
 
While these tubes do not strictly conform to the "British - Holland - German sound continuum", I have still tried to organize them in terms of their "warmness" to make this review easier for me to write and for the reader to follow. Obviously, with this many tubes (6 total?),  it is beyond my limited capabilities to provide much more than a few cursory comments regarding differences in tonality. Even so, I hope it is enough to help others decide which they might be interested in procuring.   
 
To begin, I have to say that all of these tridoes have seemingly unbounded crystal-clear highs, with a tight, low and punchy bass. Moreover, they are all excellent tubes, differing primarily in warmth and fowardness.  Sonically I believe these triodes are equal rivals to pentodes and yes, even heptodes, and I encourage everyone to try at least one. :)
 
First , the warmest and most mellow are the Tungsram EBC91. These are cozy and comfortable with excellent highs. I might call this a very safe tube.
 

 

Second, we have a tie. The Mullard EBC91 and the Philips Miniwatt CV452/EBC90 (6AT6). These tubes have a similar warmth to the Tungsram, but are just a bit brighter. Even though the Mullards were manufactured in the Blackburn factory and the Philips in the Heerlen factory, these two tubes sound identical to me, and in fact, appear to have identical construction. At the least, the EBC91 should have more gain, but since the LD 1+ is configured to derive no gain from driver tubes, it is hard for me to discern small differences in output level. Either way, if you like the warm, classic Mullard sound, either of these is a keeper. Excellent tubes.
 

 

Third, the Telefunken EBC91. These are less warm than the Mullard, but brightness and trebel detail is about the same. I did not find them as foward and bright as the Telefunken EK90 and EH900S. So if the Mullard sound is just a little too warm for you, these just might fit the bill. These too are excellent tubes.

 

 

Fourth, the Lorenz EBC91. These are noticably less warm than the Mullards, but still, as AFB notes, while they are quite forward, the vocals have this sultriness about them, which is hard to describe. That and the crystal-clear highs and strong bass, make these quite special in my opinion. Again, excellent tubes, but they require some time to fully appreciate them.
 

 

Fifth, the Amperex EBC91 (AKA RCA 6AV6). Yes indeed! Amperex put their BugleBoy name on these black plate RCAs! These are similarly forward like the Lorenz, but the vocals are smoother and more neutral. That and the crystal-clear highs and strong bass make these a standout for those who eschew the classic Mullard warmth. Since they lack the upper-bass / lower-midrange warmth of the Mullards and the sultriness of the Lorenz, these might seem to have less bass presence. However, the bass goes just as deep and has just as much punch. So on the "Euro-Tubiness Continuum", I judge these RCAs as the most "German" of the "European" tubes I have heard to date! lol
 

 

Hope this is helpful to somebody... And now I am ready for a break! :)

post #2005 of 7298

Thanks for the nice work gibosi, will keep them in mind =). Which is the one with the most stage of these? I found my Mullard CV417 very focused but rather flat.
 

post #2006 of 7298
Quote:
Originally Posted by gibosi View Post

European EBC90/EBC91 triodes
 
While these tubes do not strictly conform to the "British - Holland - German sound continuum", I have still tried to organize them in terms of their "warmness" to make this review easier for me to write and for the reader to follow. Obviously, with this many tubes (6 total?),  it is beyond my limited capabilities to provide much more than a few cursory comments regarding differences in tonality. Even so, I hope it is enough to help others decide which they might be interested in procuring.   
 
To begin, I have to say that all of these tridoes have seemingly unbounded crystal-clear highs, with a tight, low and punchy bass. Moreover, they are all excellent tubes, differing primarily in warmth and fowardness.  Sonically I believe these triodes are equal rivals to pentodes and yes, even heptodes, and I encourage everyone to try at least one. :)
 
First , the warmest and most mellow are the Tungsram EBC91. These are cozy and comfortable with excellent highs. I might call this a very safe tube.
 

 

Second, we have a tie. The Mullard EBC91 and the Philips Miniwatt CV452/EBC90 (6AT6). These tubes have a similar warmth to the Tungsram, but are just a bit brighter. Even though the Mullards were manufactured in the Blackburn factory and the Philips in the Heerlen factory, these two tubes sound identical to me, and in fact, appear to have identical construction. At the least, the EBC91 should have more gain, but since the LD 1+ is configured to derive no gain from driver tubes, it is hard for me to discern small differences in output level. Either way, if you like the warm, classic Mullard sound, either of these is a keeper. Excellent tubes.
 

 

Third, the Telefunken EBC91. These are less warm than the Mullard, but brightness and trebel detail is about the same. I did not find them as foward and bright as the Telefunken EK90 and EH900S. So if the Mullard sound is just a little too warm for you, these just might fit the bill. These too are excellent tubes.

 

 

Fourth, the Lorenz EBC91. These are noticably less warm than the Mullards, but still, as AFB notes, while they are quite forward, the vocals have this sultriness about them, which is hard to describe. That and the crystal-clear highs and strong bass, make these quite special in my opinion. Again, excellent tubes, but they require some time to fully appreciate them.
 

 

Fifth, the Amperex EBC91 (AKA RCA 6AV6). Yes indeed! Amperex put their BugleBoy name on these black plate RCAs! These are similarly forward like the Lorenz, but the vocals are smoother and more neutral. That and the crystal-clear highs and strong bass make these a standout for those who eschew the classic Mullard warmth. Since they lack the upper-bass / lower-midrange warmth of the Mullards and the sultriness of the Lorenz, these might seem to have less bass presence. However, the bass goes just as deep and has just as much punch. So on the "Euro-Tubiness Continuum", I judge these RCAs as the most "German" of the "European" tubes I have heard to date! lol
 

 

Hope this is helpful to somebody... And now I am ready for a break! :)


its very helpful, i've got a lot to learn, and i'm basically starting from scratch, and i do have some of the tubes you suggested coming !

post #2007 of 7298
Quote:
Originally Posted by Acapella11 View Post

Thanks for the nice work gibosi, will keep them in mind =). Which is the one with the most stage of these? I found my Mullard CV417 very focused but rather flat.
 

 

It was everything I could do just to do what I did! And now you want more? lol

 

I can say that your CV417 / EC91 / 6AQ4 is not even close to being in the same league as these EBC90 / 6AT6 and EBC91 / 6AV6. As best as I can remember, for one thing, the 6AQ4 is quite dry. And I have this vague understanding that some degree of wetness / reverberation is required in order to convey a sense of space. The EBC9X tubes do convey a nice sense of space, but I am not able to differentiate among them at this time....

 

As AFB has all of these tubes (with the exception of the RCA I think), perhaps he will be willing to give us his impressions with respect to stage. And further, MIKELAP has recently amassed a nice assortment of American 6AV6, and perhaps he too will jump in.

post #2008 of 7298

I have been looking for some tracks to help me evaluate bass, especially sub-bass, and I have been told that this is a good test. What do you think?

 

post #2009 of 7298
Quote:
Originally Posted by gibosi View Post

 

It was everything I could do just to do what I did! And now you want more? lol

 

I can say that your CV417 / EC91 / 6AQ4 is not even close to being in the same league as these EBC90 / 6AT6 and EBC91 / 6AV6. As best as I can remember, for one thing, the 6AQ4 is quite dry. And I have this vague understanding that some degree of wetness / reverberation is required in order to convey a sense of space. The EBC9X tubes do convey a nice sense of space, but I am not able to differentiate among them at this time....

 

As AFB has all of these tubes (with the exception of the RCA I think), perhaps he will be willing to give us his impressions with respect to stage. And further, MIKELAP has recently amassed a nice assortment of American 6AV6, and perhaps he too will jump in.

 

Quote:
Originally Posted by gibosi View Post

I have been looking for some tracks to help me evaluate bass, especially sub-bass, and I have been told that this is a good test. What do you think?

 

 

Yes, as I have a pair of most of those same triodes, I should be able to give a few extra comments from memory:

 

- Tungsram EBC91 are a very nice compromise as far as triodes go. Not too forward or over-detailed, and nice and mellow. These sound closer to our classic pentodes that to other triodes imo.

 

- Philips CV452, I actually haven't even had a chance to listen to these much but they seemed warm and detailed; I'd go with gibosi's comments on these.

 

- Lorenz EBC91, I had described these at length somewhere back 30 pages ago, but the key idea was that they take 30 mins to get into the music, but then have a very interesting and pleasant quality about them, sultry as I said.

 

- Telefunken EBC91, now these are different from the Lorenz, but also had just a bit of that "learning curve" imo, where it took 10 mins to make sense of what you hear. They, indeed, sounded much less forward than all the other Telefunken tubes I've tested (which is a good thing).

 

If you just want an easy -and hopefully cheap- triode ride, I'd suggest trying to get a pair of those Lorenz tubes first (the real ones, not the SEL Lorenz or other). The Tungsram and Tele are also very nice, but the former I have seen no other examples of on ebay (not the same un-German-looking ones at least) and the latter are way too expensive to be worth it compared to the other German triode offerings.

 

About sub-bass -a difficult topic actually- yes, James Blake is the de facto test standard lol; I know few other low-key albums that go that low in frequency and enable you to test bass that low. He also has an old two-track EP called "Air and Lack Thereof", and the first track with that same name is also a very good test track imo (half of the track is the guy just playing between bass and sub-bass as the only instrument).

 

20h on my M.B.L.E Mazda EH90, and I have to say that while these share nothing with my Siemens tubes -or German sound at all- they are top tier tubes. Yes, they are warm. No, it's not what I like or seek. But, they sound great, detailed, ambient, real, physiological/human; and the bass is a kind of the cherry on the cake, deep rumbling bass that improved a fair amount with burn-in. My hopes are, like that hypnos' tubes, mine will get even better after 30h.

 

Anyway, they're not Siemens, but I still recommend them!

post #2010 of 7298

Hi guys.

 

Just a further snippet in the ongoing Siemens EH90 saga (headache?).

 

When I received my 2nd pair, I thought I had hit the jackpot - 'made in germany' on the back and 3-digit number on the top of the tubes - cracked open my favourite bottle of wine (you can keep your champers!). Then...I looked more closely near the bottom. Lo and behold : B5I4!! Now my schooldays geography is a bit rusty, but I never knew Blackburn is in Germany!

 

AFB and gibosi are spot-on about THE LIE - how do they get away with it (or are we all missing something?). Very annoying/disappointing. ALMOST put the cork back in the bottle, but decided to slurp by way of solace rather than joy! Mind you, a slight smile returned when they proved to be totally SILENT (the first a little less so). It widened a bit more when I could have sworn the bass sounded even deeper/richer - a possible consequence of the quieter tubes? Or expectation/hope!...Whatever, they were at least a match for the 1st pair, with no burn-in, so it bodes well...And then I reminded myself of how magical the first have become (for me, anyway - as I am sure for others) -and the smile grew, and another glass of wine made its way down the gullet. Lovely...

 

BTW. Above the B****s are the letters GE1 - which I first thought stood for 'Germany'. Silly me. Any ideas folks?

 

Anyway, here's some more pics...something of slight interest - if you look closely, the only difference I could discern was the width of the metal laterals seen through the rectangular holes (forgive my ignorance as to what they are). They are wider on the 'made in germany' ones. So obviously not TOTALLY identical.

Another point - the first pair were identical, but the boxes different : one said 'heXode', the other 'hePtode'. The 2nd pair had 'heXode' on the boxes. It all looks like a conspiracy to me!!!

 

Good luck everyone...(Top pic 2nd pair, middle/bottom 1st left, 2nd right)

 

 

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