Help Identify This 12AX7

[Joe]

Hello to All:

Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.

No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.

I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.

Any ideas.


Thanks.

Joe

[Phil Symonds]

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

The seams are one tell-tale sign of a Mullard, but it's hard to be sure
without good pictures.

[Phil Symonds]

Put the tube in the freezer for an hour. When you remove it, there is a
very brief time when any writing or other impressions that used to be there
might be visible. Work quickly. It's worth a try. The coveted Mullards
have a "B" for the Blackburn plant in the manufacture code.

Telefunkens usually have a diamond shape impressed on the underside between
the pins. Is there anything there?

Phil

[Lord Valve]

Five bucks says it's a Yugo.

LV

Post by Phil Symonds
Put the tube in the freezer for an hour. When you remove it, there is a
very brief time when any writing or other impressions that used to be there
might be visible. Work quickly. It's worth a try. The coveted Mullards
have a "B" for the Blackburn plant in the manufacture code.
Telefunkens usually have a diamond shape impressed on the underside between
the pins. Is there anything there?
Phil

[Jim Anable]

Post by Lord Valve
Five bucks says it's a Yugo.
LV

For once, my money is with Willie.

Contrary to popular response, it is most likely NOT a Mullard. I have many
Mullards. They almost always only have one visible seam on the top of the
envelope, not a crosshatch or +. But Ei/Yugo always has that configuration. I
have one tube the looks Mullard with the crosshatch, but no date codes and
probably something else (also standard sized plates, not long). I also have one
RCA long plate labeled "Made in Great Britain" -- but it is obviously an
Ei/Yugo! I suspect it was relabeled to get around early bans on dealing with
easter block countries (or and out and out fake).

Are the plates smooth and long? Crosshatch on the top of the envelope? Then 99%
sure it is Ei/Yugo.

Are the plates ribbed and you also find etched Mullard codes? Dual getter
supports or rectangular getter? Then it's probably Mullard. Mullard also
produced a long plate with halo getter and single support, but it is NOT common.
Mullards ALWAYS have etched date codes, although they can get worn off. Long
plate Mullards are ALWAYS ribbed plates, and Ei/Yugo are always smooth plates
(like Telefunken).

The Telefunken "tell" is the diamond embossed. The Telefunken ECC83 is long
plate, either ribbed or smooth.

Post by Lord Valve

Post by Phil Symonds
Put the tube in the freezer for an hour. When you remove it, there is a
very brief time when any writing or other impressions that used to be there
might be visible. Work quickly. It's worth a try. The coveted Mullards
have a "B" for the Blackburn plant in the manufacture code.
Telefunkens usually have a diamond shape impressed on the underside between
the pins. Is there anything there?
Phil

[CompUser]

In article <3ea84bc6.0410060339.78463303
@posting.google.com>, ***@aol.com
says...

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.

That sounds like a Mullard...

Post by Joe
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.

If you look around sides of tube, close to base,
can you see any faint remnants of printing, such
as "Made in England", or alphanumeric codes?

[CompUser]

In article

Post by CompUser
In article <3ea84bc6.0410060339.78463303
@posting.google.com>, ***@aol.com
says...

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.

That sounds like a Mullard...

Ooops, I apologize on this...while my dabbling
with tubes got severely interrupted, I've still
been reading here. I shot from my hip memory on
this one, and was wrong!

Steve

[drwow]

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

I have Mullards with ribs on top (only in the "SW" axis), I have an
Indian made tubes with ribs in one axis and some Japanese tubes with one
and two sets of rib axis.

I've only seen Japanese tubes with the ribs running "N,W,S,E"

Picture?

dw


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[Greg Pierce]

On Wed, 06 Oct 2004 09:04:49 -0400, the highly esteemed drwow enlightened

Sorry no photo, but from an "aerial view" it has glass ribs or seams in
the N, W, S, E compass positions running down the "dome." Has what I
believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

I have Mullards with ribs on top (only in the "SW" axis), I have an Indian
made tubes with ribs in one axis and some Japanese tubes with one and two
sets of rib axis.
I've only seen Japanese tubes with the ribs running "N,W,S,E"

Japanese EL34's have 4 ribs on the top, but I can't remember if I have
seen Japanese 12AX7s with the ribs. I think LV is right - from the
description it sounds like a Yugo (Ei).

[drwow]

Post by Greg Pierce
On Wed, 06 Oct 2004 09:04:49 -0400, the highly esteemed drwow enlightened

Sorry no photo, but from an "aerial view" it has glass ribs or seams in
the N, W, S, E compass positions running down the "dome." Has what I
believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

I have Mullards with ribs on top (only in the "SW" axis), I have an Indian
made tubes with ribs in one axis and some Japanese tubes with one and two
sets of rib axis.
I've only seen Japanese tubes with the ribs running "N,W,S,E"

Japanese EL34's have 4 ribs on the top, but I can't remember if I have
seen Japanese 12AX7s with the ribs.

I have some Japanese 12AX7s with 4 ribs and a coupla' 6CG7s one with 2,
one with 4.

I think LV is right - from the

Post by Greg Pierce
description it sounds like a Yugo (Ei).

I don't think I've ever had any Ei's, I didn't see LV's reply, I have
the same POS news servers Miles has, ....... my ISP outsourced to
newsfeeds.com, ...I am missing tons of posts.

dw

If, ......."The #1 Newsgroup Service in the World!", is newsfeeds.com?

We're all doomed.......

[Yet Another Phil]

drwow said...

Post by drwow
If, ......."The #1 Newsgroup Service in the World!", is newsfeeds.com?

And how. They were doing tolerably,
most of the time, until a few weeks
ago. I bet it's been a months since
I haven't seen obvious gaps in the
posts. And no, I'm not talking about
the good gaps mmy filters create!

[Greg Pierce]

On Wed, 06 Oct 2004 22:23:48 -0400, the highly esteemed drwow enlightened

Post by drwow

Post by Greg Pierce
On Wed, 06 Oct 2004 09:04:49 -0400, the highly esteemed drwow

Post by drwow

Sorry no photo, but from an "aerial view" it has glass ribs or seams in
the N, W, S, E compass positions running down the "dome." Has what I
believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

I have Mullards with ribs on top (only in the "SW" axis), I have an
Indian made tubes with ribs in one axis and some Japanese tubes with one
and two sets of rib axis.
I've only seen Japanese tubes with the ribs running "N,W,S,E"

Japanese EL34's have 4 ribs on the top, but I can't remember if I have
seen Japanese 12AX7s with the ribs.

I have some Japanese 12AX7s with 4 ribs and a coupla' 6CG7s one with 2,
one with 4.

I don't doubt it. I only found one Japanese tube (5751) in my immediate
stash and it didn't have any seams, but that doesn't mean anything. In
this same stash I have an Ei 12AT7 with 2 seams and an Amperex Bugle Boy
(globe symbol) 6DJ8 labeled "made in Holland" with 4 seams. What is needed
is a good description of the plate structure from the OP. If they are
relatively long, smooth plates, gray in color, then it is probably an Ei.

[drwow]

Post by Greg Pierce
On Wed, 06 Oct 2004 22:23:48 -0400, the highly esteemed drwow enlightened

Post by drwow

Post by Greg Pierce
On Wed, 06 Oct 2004 09:04:49 -0400, the highly esteemed drwow

Post by drwow

Sorry no photo, but from an "aerial view" it has glass ribs or seams in
the N, W, S, E compass positions running down the "dome." Has what I
believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

I have Mullards with ribs on top (only in the "SW" axis), I have an
Indian made tubes with ribs in one axis and some Japanese tubes with one
and two sets of rib axis.
I've only seen Japanese tubes with the ribs running "N,W,S,E"

Japanese EL34's have 4 ribs on the top, but I can't remember if I have
seen Japanese 12AX7s with the ribs.

I have some Japanese 12AX7s with 4 ribs and a coupla' 6CG7s one with 2,
one with 4.

I don't doubt it. I only found one Japanese tube (5751) in my immediate
stash and it didn't have any seams, but that doesn't mean anything. In
this same stash I have an Ei 12AT7 with 2 seams and an Amperex Bugle Boy
(globe symbol) 6DJ8 labeled "made in Holland" with 4 seams. What is needed
is a good description of the plate structure from the OP. If they are
relatively long, smooth plates, gray in color, then it is probably an Ei.

A picture wouldn't hurt.

dw

[Fearless Freep]

Could it be a Telefunken?

I'll have to dig out the ones I have. Don't use them much.

Freep

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

[Lord Valve]

Post by Fearless Freep
Could it be a Telefunken?
I'll have to dig out the ones I have. Don't use them much.

That's because Telefunkens sound like ass in most guitar amps.

(Shhhh - don't tell. ;-)


Lord Valve
Expert

[Jim Anable]

Post by Lord Valve

Post by Fearless Freep
Could it be a Telefunken?
I'll have to dig out the ones I have. Don't use them much.

That's because Telefunkens sound like ass in most guitar amps.
(Shhhh - don't tell. ;-)
Lord Valve
Expert

Hmmm. I'm currently using a ribbed plate Telefunken in the gain
hole of the reverb channel of my Super Reverb (modified by Rich
Koerner), and it sounds FANTASTIC. Solid bottom with even
response. Same tube sounds less than thrilling in my Marshall
2204, though.

[Go.D:-)]

Why, you found Fred! He escaped the filming of "Up Your Ass #20" when
brokenfarte flopped out his mandingo and went full-on swordsman
with a terrified, tight-sphinctered, under age hostage. The gimp spit
out the red ball, tore at its leather restraints and began to scream
like a giant bat from inside a pine box beneath the trailer. The dog
fucking lost it. Brea Deputies were called to the scene. Fred couldn't
take it no 'mo so he rolled hissef into a box of RCA's. Don't give him
the hammer Joe! Fred's closely related to the Telefunken and Brimar
clans and he's good pals with several Mullards. He don't know no Sovteks
and he sure as shit aint no chinaman. Let him live out the good life in
an old Fender.

Go in Peace ma Bruthah.

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

["OffTopic" @]

I have encountered the following manufacturers of 12AX7/ECC83/7025 tubes
sporting four seams on the glass dome:
- Matsushita
- Siemens
- Philips (not ECG Philips) family
Never seen a true British Mullard (Blackburn code) with four seams, only
two.
Does the tube flash brightly on a cold start-up?

Peter

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

[Jim Anable]

Post by "OffTopic" @
I have encountered the following manufacturers of 12AX7/ECC83/7025 tubes
- Matsushita
- Siemens
- Philips (not ECG Philips) family
Never seen a true British Mullard (Blackburn code) with four seams, only
two.

I think I have one with a very faint second seam. I have another marked
"Great Britain" that appears authentic, but has no etched codes.

Post by "OffTopic" @
Does the tube flash brightly on a cold start-up?
Peter

Some Mullards flash, some don't.

["OffTopic" @]

Post by Jim Anable

Post by "OffTopic" @
I have encountered the following manufacturers of 12AX7/ECC83/7025 tubes
- Matsushita
- Siemens
- Philips (not ECG Philips) family
Never seen a true British Mullard (Blackburn code) with four seams, only
two.

I think I have one with a very faint second seam.

I stand corrected on this one. I went back to my tube stash and found a
"Rogers Canada" tube with four clearly visible seams and a Blackburn code
(I61 B9I) on it. What a mongrel this tube is...but is sounds just fine!

I have another marked

Post by Jim Anable
"Great Britain" that appears authentic, but has no etched codes.

Got an IEC Mullard 12AX7A also marked "Great Britain" and no codes. The
"flat spots" on one mica spacer and the lack of seams, in addition to the
distinct, curly evacuation tube seal identify this as a Brimar. Those crafty
British devils!

Post by Jim Anable

Post by "OffTopic" @
Does the tube flash brightly on a cold start-up?
Peter

Some Mullards flash, some don't.

Yes, you are correct. I was trying to narrow it down to European vs.
American tubes. It is my understanding that US manufacturers made it a point
to avoid the flash-up of filaments to ensure that these tubes were suited to
serial, line voltage circuits. So, if a tube flashes, chances are that it is
of European origin. There are probably exceptions. There are always
exceptions, damnit! ;>)

[Joe]

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

Hello Again to All,

Thanks for your responses. Here's a little more info:

When viewed from the side (only one plate showing) the plate looks
like a three rung ladder centered against a wall. There is a "D"
shaped ring to one side just under the dome (the D is curved side
down. The "floor and ceiling" (if the plates are walls) are 12
pointed "star" shapes. It flashes brightly when the amp is first
turned on.

There are no markings etched in the glass anywhere.

Thanks again.

Joe

[*Good_Virus]

That's Fred alright!

Post by Joe
Hello Again to All,
When viewed from the side (only one plate showing) the plate looks
like a three rung ladder centered against a wall. There is a "D"
shaped ring to one side just under the dome (the D is curved side
down. The "floor and ceiling" (if the plates are walls) are 12
pointed "star" shapes. It flashes brightly when the amp is first
turned on.
There are no markings etched in the glass anywhere.
Thanks again.
Joe

["OffTopic" @]

Four seams, D-shape getter, Bright start-up flash, ladder anode, 12-pointed
mica spacers.
Sounds like an old (late 50's to early 60's) Philips (Herleen, Holland) tube
to me. I am looking at one right now (labeled Rogers, date code 1959) that
fits the bill. No wonder it sounds good.
Any chance that the plates measure about 17-18mm between the mica spacers
(the "star" shapes)?

Post by Joe

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

Hello Again to All,
When viewed from the side (only one plate showing) the plate looks
like a three rung ladder centered against a wall. There is a "D"
shaped ring to one side just under the dome (the D is curved side
down. The "floor and ceiling" (if the plates are walls) are 12
pointed "star" shapes. It flashes brightly when the amp is first
turned on.
There are no markings etched in the glass anywhere.
Thanks again.
Joe

[*Good_Virus]

Please take your electron microscope to the following grid coordinates
and tell me if Fred has any cracked ribs. ack ack ack ack.

Post by "OffTopic" @
Four seams, D-shape getter, Bright start-up flash, ladder anode, 12-pointed
mica spacers.
Sounds like an old (late 50's to early 60's) Philips (Herleen, Holland) tube
to me. I am looking at one right now (labeled Rogers, date code 1959) that
fits the bill. No wonder it sounds good.
Any chance that the plates measure about 17-18mm between the mica spacers
(the "star" shapes)?

Post by Joe

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

Hello Again to All,
When viewed from the side (only one plate showing) the plate looks
like a three rung ladder centered against a wall. There is a "D"
shaped ring to one side just under the dome (the D is curved side
down. The "floor and ceiling" (if the plates are walls) are 12
pointed "star" shapes. It flashes brightly when the amp is first
turned on.
There are no markings etched in the glass anywhere.
Thanks again.
Joe

[Joe]

I think you're right.

Check out: http://www.tube-classics.de/TC/Tubes/Valvo%20ECC83/ECC83.htm

Especially the photos of the long plate tubes.

Thanks.

Post by "OffTopic" @
Four seams, D-shape getter, Bright start-up flash, ladder anode, 12-pointed
mica spacers.
Sounds like an old (late 50's to early 60's) Philips (Herleen, Holland) tube
to me. I am looking at one right now (labeled Rogers, date code 1959) that
fits the bill. No wonder it sounds good.
Any chance that the plates measure about 17-18mm between the mica spacers
(the "star" shapes)?

Post by Joe

Post by Joe
Sorry no photo, but from an "aerial view" it has glass ribs or seams
in the N, W, S, E compass positions running down the "dome." Has what
I believe you would call long plates.
No manufacturer markings except for 12AX7. Found it with a bunch of
used RCAs that I picked up.
I have been using this amazing tube in the first preamp hole in my
blackface style bruno amp. Lots of power, tone, sustain. It's like no
other that I own.
Any ideas.
Thanks.
Joe

Hello Again to All,
When viewed from the side (only one plate showing) the plate looks
like a three rung ladder centered against a wall. There is a "D"
shaped ring to one side just under the dome (the D is curved side
down. The "floor and ceiling" (if the plates are walls) are 12
pointed "star" shapes. It flashes brightly when the amp is first
turned on.
There are no markings etched in the glass anywhere.
Thanks again.
Joe