Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: pbman1953 on September 08, 2024, 09:20:15 am

Title: Can anyone ID this tube?
Post by: pbman1953 on September 08, 2024, 09:20:15 am
Can anyone tell from the marking/font what brand this could be?


Thanks
Title: Re: Can anyone ID this tube?
Post by: HotBluePlates on September 08, 2024, 07:16:53 pm
Can anyone tell from the marking/font what brand this could be?

The label is meaningless, nearly always.

I assume there is no diamond mark between the pins (https://londonjazzcollector.wordpress.com/wp-content/uploads/2014/05/telefunken-ecc83-12ax7-diamond-1800-ljc.jpg)?  If not, then the flat-plate construction reveals this is an Ei tube (https://dougstubes.com/products/ei-ecc83).
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 09, 2024, 06:11:43 am
There is a mark between the pins but hard to make out. I took a picture of it and after zooming in could be a diamond
Title: Re: Can anyone ID this tube?
Post by: mresistor on September 09, 2024, 07:41:53 am
If there is a small diamond between the pins then it's a Telefunken. Oh sorry I see HBP already elicited this in the link he provided.


Is that a dab of RTV between the pins? 
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 09, 2024, 07:57:40 am
If there is a small diamond between the pins then it's a Telefunken. Oh sorry I see HBP already elicited this in the link he provided.


Is that a dab of RTV between the pins?


Rtv?
Title: Re: Can anyone ID this tube?
Post by: mresistor on September 09, 2024, 08:37:59 am
Silicon Sealant, comes in a tube usually. What exactly is this substance on the bottom of the tube between the pins?  It ain't normal, does this tube have a crack in the glass at the base?



Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 09, 2024, 09:30:28 am
Silicon Sealant, comes in a tube usually.


That's true there was
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 09, 2024, 03:45:38 pm
Silicon Sealant, comes in a tube usually. What exactly is this substance on the bottom of the tube between the pins?  It ain't normal, does this tube have a crack in the glass at the base?


Good eye, no crack,  this came out of a tube pre-amp and the tech used the sealant on the tube stabilize it
Title: Re: Can anyone ID this tube?
Post by: mresistor on September 09, 2024, 03:48:03 pm
Thanks for the reply   I did finally think that maybe it was for some purpose like that..   cheers. 
Title: Re: Can anyone ID this tube?
Post by: HotBluePlates on September 09, 2024, 05:10:43 pm
There is a mark between the pins but hard to make out. ...

99% chance it's an Ei tube.

Try looking at the getter ring instead, where the vertical post attaches.  There's an obvious tell there that will definitely say whether this tube is a
Telefunken:

   - If the getter is not a complete ring, but dips inward where the post attaches, that's a Telefunken.
   - If it doesn't dip inward (and remains a complete circle), then it's an Ei tube.



(https://i.imgur.com/pw44jhj.png)
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 09, 2024, 05:24:26 pm
There is a mark between the pins but hard to make out. ...

99% chance it's an Ei tube.

Try looking at the getter ring instead, where the vertical post attaches.  There's an obvious tell there that will definitely say whether this tube is a
Telefunken:

   - If the getter is not a complete ring, but dips inward where the post attaches, that's a Telefunken.
   - If it doesn't dip inward (and remains a complete circle), then it's an Ei tube.



(https://i.imgur.com/pw44jhj.png)
Title: Re: Can anyone ID this tube?
Post by: HotBluePlates on September 09, 2024, 07:16:40 pm
That is an Ei ECC83.  Flat plate (which makes people think "Telefunken"), but no inward dip at the getter mounting post.
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 09, 2024, 07:34:20 pm
Thanks! Still good tube, right?
Title: Re: Can anyone ID this tube?
Post by: HotBluePlates on September 10, 2024, 04:04:31 pm
Still a 12AX7, yes.

And Ei was at least some part of the Philips family of companies in Europe.
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 10, 2024, 05:22:23 pm
If it were you. would you say the EI or a long plate RCA would sound better?
Title: Re: Can anyone ID this tube?
Post by: acheld on September 11, 2024, 10:13:48 am
If it were you. would you say the EI or a long plate RCA would sound better?

It's ALWAYS in the ears of the listener. 

As for me, I can't tell the difference between good (meaning "normally functioning") tubes of one brand vs another.

I've had more, but very intermittent, problems with microphony from long plate ECC83  tubes than the others; and various brands seem to be more reliable in my hands, but this is only my very biased opinion, based on scarce personal data.  I admit that I like Telefunken tubes based on the name alone.

Once upon a time, I tried to listen to as many tubes in this comparator https://www.tubedepot.com/pages/tube-comparison-tool (https://www.tubedepot.com/pages/tube-comparison-tool) as I could.  I really couldn't tell any differences.   But I am old.   You certainly may hear differences!   That's why it is dealer's choice!
Title: Re: Can anyone ID this tube?
Post by: Willabe on September 11, 2024, 10:33:32 am
They say that Telefunken tubes were some of the finest vacuum tubes ever made. They say they last forever because of the build quality, the materials and the vacuum.   
Title: Re: Can anyone ID this tube?
Post by: pbman1953 on September 11, 2024, 01:44:33 pm
If it were you. would you say the EI or a long plate RCA would sound better?

It's ALWAYS in the ears of the listener. 

As for me, I can't tell the difference between good (meaning "normally functioning") tubes of one brand vs another.

I've had more, but very intermittent, problems with microphony from long plate ECC83  tubes than the others; and various brands seem to be more reliable in my hands, but this is only my very biased opinion, based on scarce personal data.  I admit that I like Telefunken tubes based on the name alone.

Once upon a time, I tried to listen to as many tubes in this comparator https://www.tubedepot.com/pages/tube-comparison-tool (https://www.tubedepot.com/pages/tube-comparison-tool) as I could.  I really couldn't tell any differences.   But I am old.   You certainly may hear differences!   That's why it is dealer's choice!




Thanks for the link! I swapped back and forth and the Ei won. The Ei was similar to the RCA in mid and high end but the lows were tighter and not as blossomy.   Can't say blossom is bad but for what I do t sounded better
Title: Re: Can anyone ID this tube?
Post by: bmccowan on September 12, 2024, 06:59:41 am
They say that Telefunken tubes were some of the finest vacuum tubes ever made. They say they last forever because of the build quality, the materials and the vacuum.
Those "They" folks are really smart. And I'm wondering, did Telefunken use up all that special vacuum or is it available somewhere? Very funny Willabe! :laugh:
Title: Re: Can anyone ID this tube?
Post by: Willabe on September 12, 2024, 11:07:13 am
They say that Telefunken tubes were some of the finest vacuum tubes ever made. They say they last forever because of the build quality, the materials and the vacuum.
Those "They" folks are really smart. And I'm wondering, did Telefunken use up all that special vacuum or is it available somewhere? Very funny Willabe! :laugh:

What the hell is going on here?

You got a problem with me?
Title: Re: Can anyone ID this tube?
Post by: bmccowan on September 12, 2024, 11:47:30 am
They say that Telefunken tubes were some of the finest vacuum tubes ever made. They say they last forever because of the build quality, the materials and the vacuum.
Those "They" folks are really smart. And I'm wondering, did Telefunken use up all that special vacuum or is it available somewhere? Very funny Willabe! :laugh:

What the hell is going on here?

You got a problem with me?
Being funny is never a problem. Is it?
Cheers
Title: Re: Can anyone ID this tube?
Post by: Willabe on September 12, 2024, 12:03:45 pm
Really?

Your not being funny, your takin a poke at me, being a smart ass and you know it.

What's the real problem? 
Title: Re: Can anyone ID this tube?
Post by: bmccowan on September 12, 2024, 12:37:35 pm
There is no problem.
I thought you were being funny - maybe I was mistaken? I always think the "they" pronoun is funny. So I thought you were poking fun at some Telefunken (they) promo claims. ("last forever") forever is a long time. No?
Definitely no poke at you - just the opposite - as humor helps keep us out of drudgery.
Again, cheers! 
Title: Re: Can anyone ID this tube?
Post by: Willabe on September 12, 2024, 12:41:15 pm
I hope this is true because I always thought you were a good guy and enjoy your input here.

I'm truly sorry if I got this wrong. Forgive me.
Title: Re: Can anyone ID this tube?
Post by: bmccowan on September 12, 2024, 01:03:50 pm
I hope this is true because I always thought you were a good guy and enjoy your input here.

I'm truly sorry if I got this wrong. Forgive me.

Willabe, It is absolutely 100% true. I am an extremely honest person. I am one of those Scots that believes that honor is the most important virtue we can hold.
I am also a person who tends to see humor all around us. I often hear, "why are you laughing?" So no worries - no foul, as they say. (see what I mean?)
I have great respect for you and the other moderators here and strive to contribute productively, along with the occasional attempts to make people smile.
Regards
Title: Re: Can anyone ID this tube?
Post by: Willabe on September 12, 2024, 01:06:39 pm
Ok, good. Sorry again, my mistake.