Can someone help me identify this 12ax7 tube?

psychoanima

Member
Messages
6
Hi all, recently I got this tube as a gift and since there is no name on it can some expert tell me which 12ax7 is this?

Thank you
 

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94prs22

Platinum Supporting Member
Messages
1,293
You're welcome, to give a bit more detail, it's a Telefunken "2 hole" smooth plate, it's the most common type of smooth plate Telefunken 12ax if I'm remembering correctly. Most of the aura/hype around these tubes comes from the audiophile community, IMHO. I've got/used a small handful of these over the years (still have 3 or 4), they are very balanced/smooth sounding. More balanced than the other tubes from Europe in this 50s-70s time period to my ears. I tend to reach for other manufacturers for v1 in my amps, Siemens, Mullard, or Philips but that's just me. Lot's of folks look at this tube as one of the holy grails of audio tubes.
 

psychoanima

Member
Messages
6
You're welcome, to give a bit more detail, it's a Telefunken "2 hole" smooth plate, it's the most common type of smooth plate Telefunken 12ax if I'm remembering correctly. Most of the aura/hype around these tubes comes from the audiophile community, IMHO. I've got/used a small handful of these over the years (still have 3 or 4), they are very balanced/smooth sounding. More balanced than the other tubes from Europe in this 50s-70s time period to my ears. I tend to reach for other manufacturers for v1 in my amps, Siemens, Mullard, or Philips but that's just me. Lot's of folks look at this tube as one of the holy grails of audio tubes.
Thanks for additional info! Here's a funny story how I got it. I bought second hand chinese hifi tubecube 7 amp. Seller said that he will include for free 2 el84 and one 12ax7 that he found from somewhere, no name, but to have something to start with.
So I reiceved an amp and in the meantime I found one guy that is selling tubes. He invited me at his place and told me to bring my tube amp since it's easy to carry, so I can play different brands. First I search for nice sounding el84 and my choice was telefunken - awesome kick! Then he asked me, what would I like to try from 12ax7. I read a lot about not so cheap telefunken 12ax7 so I asked him for that one. Then he took out my "no name" 12ax7 from amp, he stared at it- no words. He aim it to light source - no words. He bring it very close to his eyes and said: "dude, you already got one telefunken." I didn't trust him truth to be told, that's why I posted pic here, to get another confirmation Oh! And I bought one additional 12ax7, a philips miniwatt! To my ears it sound bit better than telefunken. I guess we both have similar taste
 

94prs22

Platinum Supporting Member
Messages
1,293
Now that's a great story! I use a Glow Audio Amp One integrated stereo in my work office. Yes, it's overkill but it's a great conversation starter. And I have Telefunken El84s in it right now.

Using a simple amp like the Tubecube 7 is a great way to hear the differences between tubes through playing the same song through the same speakers. Happy listening!!!
 

GlideOn

Member
Messages
292
Yep, the long gray plate and large halo getter are a giveaway of a typical Telefunken. Very well made and durable tubes if anything, but not a revered as the "Diamond Blackplate" Telefunken.

Those are historically very clean almost clinical sounding tubes. Almost HD quality to them. I have them everywhere in my Fisher 500C and got to try them
in various amps and positions. Great in HiFi amps but kind of an acquired taste in guitar amps. Maybe a good V2 tonestack or reverb/tremolo driver tube helps keep things tight.

However the consensus is that old Mullards/Rogers, GE, Amperex, Raytheon and RCA (all long plates) sounded best for guitar. Imho, TungSol and re-issue Mullard are the closest to that oldschool mojo today.

I wouldn't pay more than $40 a pop for a good running one, the one you posted had some serious scratches ontop.
 

94prs22

Platinum Supporting Member
Messages
1,293
"the one you posted had some serious scratches ontop."

That's printing in various states of being rubbed off on the top of the tube in the picture.
 
Messages
1,550
One with excessive finger oils on it?

There's sometimes a ghost image of the legend left on the glass that can be seen in decent light, but Tele's I've had do have a weak white paint logo.

Telefunken tubes def have some value to audiophiles as mentioned. In guitar amps they're not incredibly special.

I have a vintage overdrive that lets me hear the tube, it's fantastic. I usually run a 12AT or AY7 in to mellow it out, as I don't like overdrives that start out heavily distorted, it's a real tone killer.

I can try any preamp tube and get a real world tone test, how hot is, is it microphonic, etc.


P1360384.JPG
P1360388.JPG


Personally, I handle them very carefully to preserve the logos, also not a big fan of the baked on fingerprints leftover from improper handling.

I'd quit using this massive dinosaur overdrive from 1997, but then realize I could sonically test preamp tubes with it, a keeper for life now.

Handle your tubes by the base, especially while removing - gentle rocking motion - or installing. Be aware of bent pins and gently straighten as needed. Do not ever force a tube into position, you might be off one leg, in some amps it's pretty hard to see what you're doing.
 

GlideOn

Member
Messages
292
"the one you posted had some serious scratches ontop."

That's printing in various states of being rubbed off on the top of the tube in the picture.

It looked like scratches from the thunbnail, in which case it wouldn't matter how valuable a tube it is, bad tube is a bad tube
 

Timbre Wolf

>thermionic<
Platinum Supporting Member
Messages
12,014
Very well made and durable tubes if anything, but not a revered as the "Diamond Blackplate" Telefunken.

Can you elaborate on this particular diamond blackplate tube? Any photos? I've never heard of such a Telefunken, and would be curious to find out more. Thanks!
 

94prs22

Platinum Supporting Member
Messages
1,293
It looked like scratches from the thunbnail, in which case it wouldn't matter how valuable a tube it is, bad tube is a bad tube
Ah, that makes sense, I wasn't able to tell that they weren't scratches until I selected the picture and zoomed in.
 

GlideOn

Member
Messages
292
Can you elaborate on this particular diamond blackplate tube? Any photos? I've never heard of such a Telefunken, and would be curious to find out more. Thanks!
They have a black, ribbed plate and have a diamond logo on the bottoms of the tube. They are rarer about as robust, totally rich as a 12AX7 gets. But at the end of the day as a preamp tube in a guitar amp, it's not going to be posess crazy special properties, speakers are infinitely more important and impact the tone more than anything else. Changing a single tube is a drop in the bucket.

But for guitar, again it's a highly subjective thing. Personally a new Mullard or TungSol gets you 98% the way for hundreds less. And likely quieter.
 

Timbre Wolf

>thermionic<
Platinum Supporting Member
Messages
12,014
They have a black, ribbed plate and have a diamond logo on the bottoms of the tube. They are rarer about as robust, totally rich as a 12AX7 gets. But at the end of the day as a preamp tube in a guitar amp, it's not going to be posess crazy special properties, speakers are infinitely more important and impact the tone more than anything else. Changing a single tube is a drop in the bucket.

But for guitar, again it's a highly subjective thing. Personally a new Mullard or TungSol gets you 98% the way for hundreds less. And likely quieter.
I'm very familiar with 17mm ribbed-plate Telefunken ECC83. But I've never heard of a black-plate version. Could you post a photo?
 

Timbre Wolf

>thermionic<
Platinum Supporting Member
Messages
12,014
Oh, yeah - thanks. Those are the standard ribbed-plate Telefunken ECC83 with gray plates. They can look darker in photos. But hold them in your hand, and you can see they’re gray.

The ribbed-plate are more clear, in my experience, than the flat-plate version. I actually prefer them for guitar. They have more treble extension, and deeper bass. But don’t have that signature upper-mid emphasis of the smooth-plate, that hi-fi folks value for vocal recordings.
 

GlideOn

Member
Messages
292
Oh, yeah - thanks. Those are the standard ribbed-plate Telefunken ECC83 with gray plates. They can look darker in photos. But hold them in your hand, and you can see they’re gray.

The ribbed-plate are more clear, in my experience, than the flat-plate version. I actually prefer them for guitar. They have more treble extension, and deeper bass. But don’t have that signature upper-mid emphasis of the smooth-plate, that hi-fi folks value for vocal recordings.
Indeed they are gray, though I have RCA 12AX7 'Blackplate' that looks a similar shade of dark gray. They're pretty freakin' close looking. So are Mullards from the same era.

There's also the 'Black Diamond' reissue, those have much shorter plate structure though I have no experience with those I would wager to say if they're as comparable as Genelex 12AX7 the results should be pretty impressive for the money around $45 a Era.

I love NOS tubes and they do sound, operate better than most current but at $150 a pop they stop making any kind of rational sense for the working man. There are better, more productive upgrades for the money.
 

Timbre Wolf

>thermionic<
Platinum Supporting Member
Messages
12,014
Indeed they are gray, though I have RCA 12AX7 'Blackplate' that looks a similar shade of dark gray. They're pretty freakin' close looking. So are Mullards from the same era.
For reference, here are some genuine black-plate Mullard ECC83 from the early-'50s:
index.php

Later '50s gray-plate Mullard ECC83
images
images


Mid-'50s black-plate RCA 12AX7:
20200508123747-520c1814.jpg


And late-'50s RCA gray-plate 12AX7:
20200508123752-fbe74e1d-me.jpg


There's also the 'Black Diamond' reissue, those have much shorter plate structure though I have no experience with those I would wager to say if they're as comparable as Genelex 12AX7 the results should be pretty impressive for the money around $45 a Era.
Those are Slovakian (JJ)
telefunken_matched_pair_of_ecc83_tk_w_balanced_tro_matched_pair_of_ecc83_tk_1568119872_1502636.jpg
 

GlideOn

Member
Messages
292
Here's a sample of some of my 12AX:

Left to right:

2018 JJ 12AX7

2020 Genelex Gold Lion Goldpin 12AX7

Mid 60s RCA 12AX7

Mid 60s Rogers (rebranded Mullard) 12AX7

Mid 60s Telefunken Smooth 12AX7

Late 50s/early 60s RCA "Blackplate"

Mid 60s Raytheon
 

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