[Lord Soth]

Thanks, Lord Soth, that's a huge help.  I've never dealt with that eBay seller before, but I didn't read any negative reviews re: inaccurate or deceptive descriptions.

I'm not getting a real tubey sound from these after about 25 hours, but I'm assuming these are silver shields (the vertical piece with the A4 9L stamped on it?).  I definitely like what I'm hearing.  Don't the later versions have a very thin getter support, like these?

Also, re: the =\= manufacturing symbol, is that literally  =\=  stamped or printed somewhere, and if so, where would it normally appear?  I'll have to pull mine tomorrow and have a closer look.

Anyway, I really appreciate you sharing your knowledge.  I've learned a lot about tubes in the past couple months, but nowhere have I found info like this re: Siemens tubes.
 

Hi,

Yes the photo in your link shows the single getter design.
These are newer tubes made in the late 1970s to 1980s.

There is no definite rule as to where the =\= symbol might show up.

The =\= symbol sometimes appears on the internal metal plate which you asked earlier.

For older tubes, it is etched and is usually very faint.
You would have to hold the tube up against a light source and rotate the tube slowly to locate it.
It is usually near the base of the tube, in the area slightly above the tube tube pins.
(By way of analogy, it is akin to holding a currency note against a light source to check out the security features.)
Sometimes the Printed labels on the tube might obscure it.

Finally, much patience is required when rolling tubes.
For these small preamp tubes, you require at least 50hrs of use before any definite tube rolling conclusions can be made.
Most famous NOS tubes might even sound downright awful if they have not been sufficiently burned in.

Have fun tuberolling !

It is an €£¥$$$$$ hobby.

As most headfiers put it, " welcome to Head Fi, sorry about your wallet!"

 

[ThurstonX]

Hi,

Yes the photo in your link shows the single getter design.
These are newer tubes made in the late 1970s to 1980s.

There is no definite rule as to where the =\= symbol might show up.

The =\= symbol sometimes appears on the internal metal plate which you asked earlier.

For older tubes, it is etched and is usually very faint.
You would have to hold the tube up against a light source and rotate the tube slowly to locate it.
It is usually near the base of the tube, in the area slightly above the tube tube pins.
(By way of analogy, it is akin to holding a currency note against a light source to check out the security features.)
Sometimes the Printed labels on the tube might obscure it.

Finally, much patience is required when rolling tubes.
For these small preamp tubes, you require at least 50hrs of use before any definite tube rolling conclusions can be made.
Most famous NOS tubes might even sound downright awful if they have not been sufficiently burned in.

Have fun tuberolling !

It is an €£¥$$$$$ hobby.

As most headfiers put it, " welcome to Head Fi, sorry about your wallet!"

 
LOL, I know that expression.  Go back a few posts and you'll see my modest collection housed in their even more modest home.  Those eight pairs cost me enough 

  (I'm not counting the GEs that came with the Lyr).
 
I don't judge any pair too harshly before they hit the 100-hour mark.  Still, ya gotta listen while yr burnin', ya know.  I've got a pretty good, patient, system for burning in.
 
I re-read Joe's Tube Lore to confirm they're genuine.  They pass the test(s).  But my eyes are a little tired now for serious examination, though I did give it a go.  I noticed stamped on the bottom, between the pins, is a "6" or a "9" depending, I suppose.

 

[Oskari]

There is no definite rule as to where the =\= symbol might show up.

The =\= symbol sometimes appears on the internal metal plate which you asked earlier.

For older tubes, it is etched and is usually very faint.

 
The not equal sign (≠) is part of the etched code (when that appears) but I haven't seen it on the internal metal plate. Can you show an example?

 

[ThurstonX]

 
The not equal sign (≠) is part of the etched code (when that appears) but I haven't seen it on the internal metal plate. Can you show an example?

 
Yeah, that's symbol I was looking for, but couldn't spot it.  According to the info available at Brent Jessee's site, the Munich factory symbol is
= with the | running through the middle (a bit different).  Regardless, I could spot any = sign.  Joe's Tube Lore says look for the ridges/seams on top (two are easy to spot, and with reading glasses I could see the very faint other two).
 
"Second, check the metal shield above the upper mica spacer. On Siemens & Amperexes it’s circular with two raised rectangular sections on opposite edges of the shield. On most fakes that shield is a perfectly flat disc."
 
Very familiar with that, and easily seen.  So, I'm not going to sweat their authenticity.

 

[Oskari]

 
Yeah, that's symbol I was looking for, but couldn't spot it.  According to the info available at Brent Jessee's site, the Munich factory symbol is
= with the | running through the middle (a bit different).

 
See the following.
 

The =\= symbol sometimes appears on the internal metal plate which you asked earlier.

 
Found one. So, there are at least five different Siemens code types.
 
Bottom code
 

1. http://www.tubemongerlib.com/gallery2/v/12AX7/Siemens+and+Halske+ECC83+1950s+Tall+Plates+Date+Codes+-+Munich+Germany.jpg.html

 
Side code, 2 different ways
 

1. http://www.tubemongerlib.com/gallery2/v/12AX7/Siemens+and+Halske+ECC83+1960s+Dual+Getter+Support+2+-+Munich+Germany.jpg.html
2. http://tctubes.com/Siemens-E83CC-12AX7.aspx

 
Metal stamp code, with ≠ and without
 

1. http://www.tubemongerlib.com/gallery2/v/6922/Siemens+and+Halske+E88CC+6922+-+1960s+Munich+-+Gray+Risers+Metal+Stamp+Date+-+SAME+DATE+A0+1n+5I.jpg.html
2. http://www.tubemongerlib.com/gallery2/v/6922/Siemens+E88CC+1970s+A-Frame+Metal+Stamp+Date+Codes+3+-+Munich+Germany.jpg.html

 

[ThurstonX]

   
See the following.
 
 
Found one. So, there are at least five different Siemens code types.
 
Bottom code
 

1. http://www.tubemongerlib.com/gallery2/v/12AX7/Siemens+and+Halske+ECC83+1950s+Tall+Plates+Date+Codes+-+Munich+Germany.jpg.html

 
 
Side code, 2 different ways
 

1. http://www.tubemongerlib.com/gallery2/v/12AX7/Siemens+and+Halske+ECC83+1960s+Dual+Getter+Support+2+-+Munich+Germany.jpg.html
2. http://tctubes.com/Siemens-E83CC-12AX7.aspx

 
Metal stamp code, with ≠ and without
 

1. http://www.tubemongerlib.com/gallery2/v/6922/Siemens+and+Halske+E88CC+6922+-+1960s+Munich+-+Gray+Risers+Metal+Stamp+Date+-+SAME+DATE+A0+1n+5I.jpg.html
2. http://www.tubemongerlib.com/gallery2/v/6922/Siemens+E88CC+1970s+A-Frame+Metal+Stamp+Date+Codes+3+-+Munich+Germany.jpg.html

 
Basically the Munich factory symbol (= with | through it) is present on all but the dual-supported getter version (last one).
 
I'll have to look closer at my CCas.  They are most similar to these, but later production (silver shields, not gray).  Pretty sure the Munich factory symbol is not present on internal stamped plate.  Hmmm, perhaps they weren't made in München.  I'm reading through search results at Tubes Asylum.  While there is some consensus about certain aspects, there's a lot of confusion, too.
 
Thanks for posting your findings 

 

 

[Oskari]

 
I'll have to look closer at my CCas.  They are most similar to these, but later production (silver shields, not gray).  Pretty sure the Munich factory symbol is not present on internal stamped plate.  Hmmm, perhaps they weren't made in München.

 
They were, don't worry.
 
Only Siemens and Tungsram used that kind of stamped plate, and your tubes aren't Tungsrams. The codes on your tubes are clearly Siemens as are the (Philips-style) seams on top.

 

[ThurstonX]

 
They were, don't worry.

 
Thanks 

 
This post (and poster) helps a lot with Siemens CCa construction and relative dating.  It relates to a long-dead eBay offer and question about it, but the info is good.  Based on his descriptions, I'd say mine are late '60s, and either 1969 or 1970, depending on how the stamps and painted numbers are interpreted.

 

[Oskari]

  Based on his descriptions, I'd say mine are late '60s, and either 1969 or 1970, depending on how the stamps and painted numbers are interpreted.

 
I suppose they could have been made in 1969 but branded in 1970.

 

[ThurstonX]

Got another for people in the know.
 
How would you interpret the following Telefunken code?  U12140040
 
Based on the TFK page on Brent Jessee's site...
 
U 12140 040
 
Day = 21
Month = 10
Year = 19[6|7]4
 
I have no idea if Telefunken made tubes in 1974, though I suspect it's likely they did.  I've no idea what the 040 at the end might signify.
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
Further research brought me to the page on which BJ based is page:
http://www.tubemuseum.org/SearchResults.asp?Cat=23
 
where it states:
"4th digit = Last digit of year (1958-1978) decade needs to be determined by construction so, 1966 or 1976 depending on inner construction clues."
 
Figures.  This photo makes me think they might be 1964, if Telefunken's production and design is anything like Siemens, as discussed above; i.e., the shield doesn't extend down from top to bottom micas.
 
 

 
Cheers 

 

 

[148124]

I wonder if there is some humm/buzzing sound when there is no music with hd600/650 ...

 

[Brouken Air]

  Hi All,
 
I am new to this forum and I appreciated a lot this thread, I learned quite a lot on tube rolling. I did it once for my amp but that's all. As I ordered a few days ago a Schiit Lyr, I have been tempted by tube rolling.... Being already an audiophile, this will not enhance the status of my bank account. 
My setup concerning Headphones, is following:
- A PC with 12 cores, 8 gb Ram, 6 TB disks and JRiver,
- linked to the PC via USB, a Zodiac Gold + Voltikus,
- Synergistic cables will link the Zodiac to my coming Lyr,
- HE500 Headphone and that's it.
 
And a Classical flac library which is getting monstruous.... (around 12 hours of listening/day)
 
I have already ordered Amperex Orange Globes, Bugle Boys, CCA Siemens, Tesla 88ECC, Russian Gold pins Gold grid 6N1P. As you can understand, I am takintg it quite seriously. But I wanted to know if dampers are mandatory, and if so what kind of dampers, there are different models. Should I use a tube extender with the Lyr in order to be able to put the dampers? 
 
Thanks already for all the informations over tubes and thanks for the coming ones
 
Charles

Given the number of answers I got, my questions are:
 
1 Stupid
or
2 Obscure and nobody understand
or
3 Not interesting
 
Could you please tell me in which category they are falling or if non of the categories applies, could you answer my question?
 
Thanks

 

[MattTCG]

Can I get some feedback from anyone who has owned this:
 
http://www.ebay.com/itm/321276730052?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

 

[Textfeud]

  Can I get some feedback from anyone who has owned this:
 
http://www.ebay.com/itm/321276730052?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I own the Telefunken ECC88 (no idea what year, but with diamond bottom etc, so genuine ones). They sound very good with my HE-500. I actually sold af my entire tube collection so I have some cash for other stuff, but kept the Telefunken ECC88. I would like to know how they compare with the E88CC if there is any sonic difference. 

 

[gibosi]

 
I have already ordered Amperex Orange Globes, Bugle Boys, CCA Siemens, Tesla 88ECC, Russian Gold pins Gold grid 6N1P. As you can understand, I am takintg it quite seriously. But I wanted to know if dampers are mandatory, and if so what kind of dampers, there are different models. Should I use a tube extender with the Lyr in order to be able to put the dampers? 
 
Thanks already for all the informations over tubes and thanks for the coming ones
 

 
First, I do not own a Lyr, but I do have considerable experience with 6DJ8 tubes in another amp... 
 
Dampers are not mandatory. However, wait until your tubes come in and then decide. If one or more is a bit microphonic, a damper just might help. That said, I have never used them.
 
Again, since I do not have a Lyr, I do not know for sure if there is enough clearance to accommodate dampers, but I suspect there is. However, a socket saver will make rolling tubes much easier, that is extracting and inserting, and they are quite popular in this forum. But again, I suggest you wait until you your tubes arrive and you have swapped them in and out a few times, and then make your decision.
 
Cheers