6EU7 To a 12AX7

MikeWall

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Apr 24, 2005, 8:39:24 AM4/24/05

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I have a SET amp with 6EU7 preamps. From tube characteristic
charts it appears a 12AX7 is identical except for socket
wiring and the filiment is center tapped. Does anyone know of a reason
to keep the rarer 6EU7 instead of rewiring the sockets to 12AX7? Thanks!

Message has been deleted

Lord Valve

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Apr 24, 2005, 1:24:31 PM4/24/05

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François Yves Le Gal wrote:

> On Sun, 24 Apr 2005 08:39:24 -0400, MikeWall <mike...@rhtc.net> wrote:
>
> > From tube characteristic
> >charts it appears a 12AX7 is identical
>

> It's close, but not identical: the 6EU7 has slightly more gain, 100 vs. 90
> for the 12AX7, which also whows a better dissipation. Anyway, you can use a
> 12AX7 in a circuit designed for the 6EU7 (with the mods you've mentioned, of
> course).

Froggy's fulla shit. Froggy needs a new specbook.

The RCA Tube Handbook (HB-3) shows *identical*
specs (inclucing all of the curves) for these two
devices, with the exception of two *very* minor
deviations in inter-element capacitance, i.e, 1.5pF
vs. 1.7pF for grid-to-plate, and 0.2pF vs. 0.46pF
for plate-to-cathode. Other than the filament system
and the basing, they are the same. Amplification
factor is 100 in either case.

Commence whining, Froggy.

Lord Valve
American

Message has been deleted

Lord Valve

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Apr 24, 2005, 2:32:31 PM4/24/05

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François Yves Le Gal wrote:

> On Sun, 24 Apr 2005 17:24:31 GMT, Lord Valve <detr...@ix.netcom.com> wrote:
>
> >Froggy's fulla shit. Froggy needs a new specbook.
>

> Bozo, next time I'll want your opinion, I'll spit at you. You can meanwhile
> get back to your corner chewing your toenails.

Froggy, this is a real head-scratcher.

It's seldom that we see even a third-rate clod like you
piss on himself so thoroughly. Keep reading, schmuck...

> http://hereford.ampr.org/cgi-bin/tube?tube=6EU7
> http://home.rochester.rr.com/piazza/AudioTubes/6eu7.html
>
> http://hereford.ampr.org/cgi-bin/tube?tube=12AX7
> http://home.rochester.rr.com/piazza/AudioTubes/12ax7a.html

Copied/pasted from the exact URLs YOU provided:
_______________________________________________

12AX7 ( http://hereford.ampr.org/cgi-bin/tube?tube=12AX7 )

Heater Characteristics
Heater Voltage ................................ 6.3/12.6 Volts
Heater Current ................................ 0.3/0.15 Amperes

Direct Interelectrode Capacitances (approx)

Each Triode
Input ......................................... 1.8 pf
Output ........................................ 1.9 pf
Grid to Plate ................................. 1.7 pf

Maximum Ratings (Design Center Values)

Each Triode
Plate Voltage ................................. 330 Volts
Plate Dissipation ............................. 1.2 Watts

Characteristics and Typical Operation

Class A Amplifier
Plate Voltage ................................. 250 Volts
Grid No. 1 Voltage ............................ -2 Volts
Amplification Factor .......................... 100
Plate Resistance (approx) ..................... 62.5K Ohms
Transconductance .............................. 1600 MicroMhos
Plate Current (Zero Signal) ................... 1.2 Ma.

For other characteristics and typical operation, see 12AX7A

-------------------------------------------------------------------------------------------

6EU7 ( http://hereford.ampr.org/cgi-bin/tube?tube=6EU7 )

Heater Characteristics
Heater Voltage ................................ 6.3 Volts
Heater Current ................................ 0.3 Amperes

Direct Interelectrode Capacitances (approx)

Each Triode
Input ......................................... 1.6 pf
Output ........................................ 0.2 pf
Grid to Plate ................................. 1.5 pf

Maximum Ratings (Design Center Values)

Each Triode
Plate Voltage ................................. 330 Volts
Plate Dissipation ............................. 1.2 Watts

Characteristics and Typical Operation

Class A Amplifier
Plate Voltage ................................. 250 Volts
Grid No. 1 Voltage ............................ -2 Volts
Amplification Factor .......................... 100
Plate Resistance (approx) ..................... 62.5K Ohms
Transconductance .............................. 1600 MicroMhos
Plate Current (Zero Signal) ................... 1.2 Ma.
_________________________________________________

> Thank you for giving me the opportunity to publicly humiliate you, sack'o
> shit. You really love to be bitch slapped, don't you?

Um, humiliation - OK, Froggy...

If "humiliation" consists of data from URLs supplied by you
which absolutely support me in every way, then I guess I'm
humiliated.

I'm not sure on exactly which planet that occurred, but I'm
pretty certain it wasn't this one.

Do we need to see this again, in case anyone missed it?

12AX7
Class A Amplifier
Plate Voltage ................................. 250 Volts
Grid No. 1 Voltage ............................ -2 Volts
Amplification Factor .......................... 100
Plate Resistance (approx) ..................... 62.5K Ohms
Transconductance .............................. 1600 MicroMhos
Plate Current (Zero Signal) ................... 1.2 Ma.

6EU7
Class A Amplifier
Plate Voltage ................................. 250 Volts
Grid No. 1 Voltage ............................ -2 Volts
Amplification Factor .......................... 100
Plate Resistance (approx) ..................... 62.5K Ohms
Transconductance .............................. 1600 MicroMhos
Plate Current (Zero Signal) ................... 1.2 Ma.

Those are copied right off the URLs you supplied, Froggy.

Damn, that must sting. There, there. There, there.

> BTW, where are the proofs of your former allegations regarding New Sensor
> owning Reflektor, dickhead?

Ask Mike yourself, Froggy. 1-800-633-5477. Or ask Ralph Trimarchi. Tell
either of 'em Lord Valve sent you.

Thanks for playing - better luck next time.

Lord Valve
Expert

Message has been deleted

stuhawk

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Apr 24, 2005, 3:56:18 PM4/24/05

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Thanks I didn't mean to be a point of contention for anyone. 90 or 100
they look verry close to me .

Message has been deleted

stuhawk

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Apr 24, 2005, 9:16:53 PM4/24/05

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What do you mean by componet dispersion? I've never heard the term in
Vacuum Tube technology. THANKS!

François Yves Le Gal wrote:

> On Sun, 24 Apr 2005 15:56:18 -0400, stuhawk <mike...@rhtc.net> wrote:
>
>
>> Thanks I didn't mean to be a point of contention for anyone.
>
>

> Don't worry, "Lord Valve" is one of our resident bigoted shrills. Every
> village has an idiot, the Internet is a global village: he's a global idiot.

>
>
>>90 or 100 they look verry close to me .
>
>

> It is very close: actual component dispersion will show a much better
> difference !
>
>

calc...@hotmail.com

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Apr 24, 2005, 10:14:40 PM4/24/05

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From memory the 6EU7 is a 12AX7 with different basing to make wiring
easier in production and more hum-free (although no serious constructor
today would run AC filaments on small signal tubes IMO). YMMV because
the tube manuals were all different and will quote slightly different
values for a variety of reasons.

Lord Valve

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Apr 24, 2005, 11:55:33 PM4/24/05

to

Here, Froggy - eat these:

etc. Every single one of 'em says "Amplification Factor = 100."

You posted a link to a datasheet with bogus data on it.
You're busted, Froggy. Crawl back into the primordial
French ooze from which you were so recently excreted
and cease spreading your putrescence here.

Lord Valve
Expert

François Yves Le Gal wrote:

> On Sun, 24 Apr 2005 18:32:31 GMT, Lord Valve <detr...@ix.netcom.com> wrote:
>
> >Froggy, this is a real head-scratcher.
>

> Then remove your fingers from your big fat hairy ass, shithead.

>
> >It's seldom that we see even a third-rate clod like you
> >piss on himself so thoroughly. Keep reading, schmuck...
>

> >> http://home.rochester.rr.com/piazza/AudioTubes/6eu7.html
>
> 6EU7 HIGH-MU TWIN TRIODE
>
> Miniature type used in high gain, resistance-coupled low-level
> audio-amplifier applications where low hum and non-microphonic
> characteristics are important. Requires miniature 9-contact socket.
>
> [...]
>
> Amplification Factor 100
>
> >> http://home.rochester.rr.com/piazza/AudioTubes/12ax7a.html
>
> 12AX7A HIGH-MU TWIN TRIODE
>
> Miniature type used as phase inverters or twin resistance-
> coupled amplifiers in radio and audio equipment. Requires
> miniature 9-contact socket. Each triode unit is independent
> of the other except for the common heater.
>
> [...]
>
> Amplification Factor 90

>
> >Copied/pasted from the exact URLs YOU provided:
>

> That's what I just did above, sack'o shit.
> You've been bitch slapped, again.
>
> Oh, and alt.asshole.factory isn't a valid newsgroup. Maybe it's your
> business adress?
>
> BTW, you still haven't proven anything regarding Reflektor. Except of of
> course that you're a moronic shithead. But we already knew that...
>
> BTW, FU2 again. Oh, and your handle "detritus" is perfect.

Message has been deleted

Lord Valve

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Apr 25, 2005, 11:57:31 AM4/25/05

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<sigh>

Froggy, you're just wrong. You know it, I know it, and all the
rest of the chickenshit losers on RAT who are giving this
litle spat wide berth know it. Amplification factor on a
12AX7 is 100 - has been for years, will be until it short-dicks
every cannibal on the Congo. You haven't come up with a
single ref other than the incorrect one you posted the original
link to, and you won't, because there aren't any. Even the
*other* 12AX7 link *you* posted says so - but you didn't
read it in the first place, you just assumed it would back
up the incorrect one. So, by all means - continue to look
like an ass. You wear it well.

Lord Valve
Expert

François Yves Le Gal wrote:

> On Mon, 25 Apr 2005 03:55:33 GMT, Lord Valve <detr...@ix.netcom.com> wrote:
>
> >Here, Froggy - eat these:
>

> Want another round, shithead? OK, here we go...

>
> >http://www.pmillett.com/tubedata/HB-3/Receiving%20Tubes%20Part%202/12AX7-A.PDF
> >(RCA HB-3, 1960)
> >http://www.mif.pg.gda.pl/homepages/frank/sheets/093/1/12AX7A.pdf (GE datasheet,
> >1963)
> >http://www.mif.pg.gda.pl/homepages/frank/sheets/020/1/12AX7A.pdf (Mazda
> >datasheet, 1968)
> >http://www.mif.pg.gda.pl/homepages/frank/sheets/127/1/12AX7A.pdf (Tung-Sol
> >datasheet, 1965)
>

> 12AX7A, not 12AX7

>
> >http://hereford.ampr.org/cgi-bin/tube?tube=6AV6 ("for other characterists" link,
> >RCA RC-29, 1975)
>

> 6AV6

>
> >http://www.drtube.com/datasheets/ecc83ph54.pdf (Philips datasheet, 1954)
> >http://www.drtube.com/datasheets/ecc83tel54.pdf (Telefunken datasheet, 1954)
> >http://www.drtube.com/datasheets/ecc83rft56.pdf (RFT datasheet, 1956)
> >http://www.drtube.com/datasheets/ecc83ph70.pdf (Philips datasheet, 1970)

> >http://www.jj-electronic.com/tube_ecc83.htm (JJ datasheet, current)a

> >http://www.eierc.com/rc/ECC83.htm (EI datasheet, current)
> >http://www.drtube.com/datasheets/e83cclor62.pdf (Lorenz datasheet, 1962)
>

> ECC83
>
> Yeah, sure...
>
> <SNIP> the rest of your rant.
>
> Thank you for letting me bitch slap you again, dickless loser. You may now
> climb back on your special needs tricycle, the one with a fourth wheel added
> for extra safety, and pedal back to your trailer.

Message has been deleted

Lord Valve

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Apr 25, 2005, 12:54:53 PM4/25/05

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Subject:
Re: 6EU7 To a 12AX7
Date:
Sun, 24 Apr 2005 14:18:34 -0400
From:
Jon Yaeger <jon...@bellsouth.net>
Organization:
BellSouth Internet Group
Newsgroups:
junk
References:
1 , 2 , 3 , 4

in article ndmn61dc8fvp4o80o...@4ax.com, François Yves Le Gal
at fle...@aingeal.com wrote on 4/24/05 1:50 PM:

>> On Sun, 24 Apr 2005 17:24:31 GMT, Lord Valve <detr...@ix.netcom.com> wrote:
>>
>>> Froggy's fulla shit. Froggy needs a new specbook.
>>
>> Bozo, next time I'll want your opinion, I'll spit at you. You can meanwhile
>> get back to your corner chewing your toenails.
>>

>> http://hereford.ampr.org/cgi-bin/tube?tube=6EU7
>> http://home.rochester.rr.com/piazza/AudioTubes/6eu7.html
>>
>> http://hereford.ampr.org/cgi-bin/tube?tube=12AX7
>> http://home.rochester.rr.com/piazza/AudioTubes/12ax7a.html
>>

>> Thank you for giving me the opportunity to publicly humiliate you, sack'o
>> shit. You really love to be bitch slapped, don't you?
>>

>> BTW, where are the proofs of your former allegations regarding New Sensor
>> owning Reflektor, dickhead?
>>

>> FU2 in order to cut the noise.
>>

>The 1st 2 references you cite for each tube show identical amplification
>factors of 100 and plate dissipations of 1.2 watts.
>
>The 2nd references show different amplification factors.
>
>Or am I missing something?
>

Indeed you are.

You missed that fact that Froggy set followups to "junk"
so that in case anyone besides me caught him bullshitting
the post wouldn't show up on RAT. Froggy's chickenshit.

Lord Valve
Expert

Lord Valve

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Apr 25, 2005, 12:57:57 PM4/25/05

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Subject:
Re: 6EU7 To a 12AX7
Date:

Mon, 25 Apr 2005 00:54:36 GMT
From:
robert casey <wa2...@ix.netcom.com>
Organization:
EarthLink Inc. -- http://www.EarthLink.net
Newsgroups:
junk
References:
1 , 2 , 3 , 4 , 5 , 6

>>
>> [...]
>>
>> Amplification Factor 90
>>
>>
>And we all know that all web sites are error free....

...especially the ones Froggy hangs out on.

Make sure you check the followup setting on anything
Froggy posts here. Froggy stepped in something, and
he's trying to cover his tracks.

Lord Valve
Expert

Message has been deleted

John Stewart

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Apr 25, 2005, 1:02:42 PM4/25/05

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Lord Valve wrote:

Most of the RCA HB's give only average data. The 12AX7 Mu varies from 90 to 105,
depending on operating conditions. MU is not a constant. JLS

John Stewart

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Apr 25, 2005, 1:05:48 PM4/25/05

to

Most of the RCA HB's give only average data. The 12AX7 MU varies from 90 to 105, depending on operating conditions. MU is not a constant. JLS

See at http://frank.pocnet.net/sheets/127/1/12AX7A.pdf

Jon Yaeger

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Apr 25, 2005, 1:12:56 PM4/25/05

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in article 426D2129...@ix.netcom.com, Lord Valve at
detr...@ix.netcom.com wrote on 4/25/05 12:54 PM:

> Subject:
> Re: 6EU7 To a 12AX7
> Date:
> Sun, 24 Apr 2005 14:18:34 -0400
> From:
> Jon Yaeger <jon...@bellsouth.net>
> Organization:
> BellSouth Internet Group
> Newsgroups:
> junk
> References:
> 1 , 2 , 3 , 4
>
>
>

> Indeed you are.
>
> You missed that fact that Froggy set followups to "junk"
> so that in case anyone besides me caught him bullshitting
> the post wouldn't show up on RAT. Froggy's chickenshit.
>
> Lord Valve
> Expert

How can he do that??

I posted a very benign reply, and it doesn't show up.

Jon

Lord Valve

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Apr 25, 2005, 1:28:46 PM4/25/05

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John Stewart wrote:

Depending on operating conditions, you can vary it much more widely than that.

SPECS are what is being discussed here, and Froggy has posted
a link to a page which shows a spec not listed on any other
datasheet or manual.

> MU is not a constant.

No shit.

LV

Lord Valve

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Apr 25, 2005, 1:35:39 PM4/25/05

to

Jon Yaeger wrote:

Anyone can do it.

Almost no-one does, because it's rude. Of course,
he *is* French...

> I posted a very benign reply, and it doesn't show up.

When you click your "reply to group" icon, check what group comes up in the
"to" field.

If it's not he one you thought you were replying to, just erase it and
type the right one in. It's just Froggy's snotty little way of making
you jump through an extra hoop before you can debunk his crap.

LV

Message has been deleted

my_name_here

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Apr 26, 2005, 12:39:47 AM4/26/05

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Lord Valve <detr...@ix.netcom.com> wrote in
news:426D13B6...@ix.netcom.com:

> .... will be until it short-dicks
> every cannibal on the Congo....

That's what's so awesome about lurking this group. Something new to learn
every day!

Patrick Turner

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Apr 26, 2005, 8:28:36 AM4/26/05

to

Lord Valve wrote:

The French man's web reference is as follows for 6EU7:-

"""""" Miniature type used in high gain, resistance-coupled
low-level
audio-amplifier applications where low hum and non-microphonic
characteristics are important. Requires miniature 9-contact socket.

Heater Voltage (ac/dc):
.............................................................. 6.3 volts
Heater Current:
................................................................... 0.30 amperes

Class A1 Amplifier (Each Unit)
Maximum Ratings (Design-Center Values)

Plate Voltage
................................................................................ 330
volts
Grid Voltage (Negative-bias value)
........................................... 55 volts
Grid Voltage (Positive-bias value)
............................................... 0 volts
Plate Dissipation
.......................................................................... 1.2 watts

Amplification Factor
............................................................................. 100
""""""

Now, all I see is µ = 100.

What is bogus about this?

Patrick Turner.

Patrick Turner

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Apr 26, 2005, 8:31:44 AM4/26/05

to

Lord Valve wrote:

> <sigh>
>
> Froggy, you're just wrong. You know it, I know it, and all the
> rest of the chickenshit losers on RAT who are giving this
> litle spat wide berth know it. Amplification factor on a
> 12AX7 is 100 - has been for years, will be until it short-dicks
> every cannibal on the Congo. You haven't come up with a
> single ref other than the incorrect one you posted the original
> link to, and you won't, because there aren't any. Even the
> *other* 12AX7 link *you* posted says so - but you didn't
> read it in the first place, you just assumed it would back
> up the incorrect one. So, by all means - continue to look
> like an ass. You wear it well.
>
> Lord Valve
> Expert

Not every 12AX7 has a measured µ of 100.....

Patrick Turner.

Message has been deleted

Lord Valve

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Apr 26, 2005, 12:45:29 PM4/26/05

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Patrick Turner wrote:

ROFLMBFAO!

Ask Froggy. After all, HE posted it. He also posted a link to
another page (evidently made up by a dude who specializes
in re-drawing old Ampeg schematics, for some reason) which
shows the amplification factor for a 12AX7 as 90. *Every*
datasheet from *every* major specbook shows 100, but
Froggy has his undies in a bunch about it.

Ribbet, ribbet, ribbet - SQUASH.

Lord Valve
American

Message has been deleted

dizzy

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Apr 26, 2005, 7:27:34 PM4/26/05

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On Tue, 26 Apr 2005 19:09:54 +0200, François Yves Le Gal
<fle...@aingeal.com> wrote:

>On Tue, 26 Apr 2005 16:45:29 GMT, Lord Valve <detr...@ix.netcom.com> wrote:
>
>>Ribbet, ribbet, ribbet - SQUASH.
>

>In your dreams, Neutered Loser™.
>
>Have you hugged your Karl Rowe love doll today?

You lost the argument, dude.

Patrick Turner

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Apr 26, 2005, 7:51:16 PM4/26/05

to

Lord Valve wrote:

In Northern Oz the Cane toads which are highly poisenous imported pests from
Sth America grow to a size of a large fat cat.

They like to use the road system to migrate and after being introduced to Qld cane farms
to
control insect pests, thay have bred and spread unchecked across thousands
of kilometers of wild places, killing the uninitiated wild life not use to the
powerful toxin their bodies contain. They look like a good meal, but are the opposite.
So ppl have fun mowing them down in their FWD.

So frog squashing is appropriate up north, but one does have to hose the vehicle down
after a long trip.

If you think you have a frog problem with Yves, try venturing this way,
I'll give yer fukkin frog fukkin problems.

Most 12AX7 or 6EU7 actually have µ = 100, +/-5%, which is determined by the
relative dimensions between cathode, grid and anode and the wire pitch
of the helical grid winding.
Usually there is less than 10% variation in µ regardless of whether the tube was made,
since its easy to make a triode to get a certain value of µ.
In actual fact variations of µ occur between samples.....

Maybe your concerns are akin a texas tornado occuring in a coffee cup.

Chill out, move on, and don't worry about the occasional frogatorial statement
that's only 90% right.

If travelling in our north, there is no law compelling ppl to run over cane toads.
If you miss one, no law says you have to back up and try again.

Patrick Turner.

>
>
> Lord Valve
> American

Lord Valve

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Apr 27, 2005, 2:48:37 AM4/27/05

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Patrick Turner wrote:

> Most 12AX7 or 6EU7 actually have ต = 100, +/-5%, which is determined by the

> relative dimensions between cathode, grid and anode and the wire pitch
> of the helical grid winding.

> Usually there is less than 10% variation in ต regardless of whether the tube was made,
> since its easy to make a triode to get a certain value of ต.

So, going by what you just wrote, Froggy posted bad data, and gave bad advice based on it.

> In actual fact variations of ต occur between samples.....

>
> Maybe your concerns are akin a texas tornado occuring in a coffee cup.

I don't give a shit about the actual mu.

Froggy got busted posting bullshit, and has been trying
to wiggle out of it for several days now.

> Chill out, move on, and don't worry about the occasional frogatorial statement
> that's only 90% right.

He was 100% wrong, and 110% full of Frog Shit.

Lord Valve
American

Message has been deleted

Ned Carlson

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Apr 29, 2005, 2:53:06 AM4/29/05

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On Sun, 24 Apr 2005 08:39:24 +0000, MikeWall wrote:

> I have a SET amp with 6EU7 preamps. From tube characteristic charts it
> appears a 12AX7 is identical except for socket wiring and the filiment is
> center tapped. Does anyone know of a reason to keep the rarer 6EU7 instead
> of rewiring the sockets to 12AX7? Thanks!

Decent NOS 6EU7 are usually cheaper than decent NOS 12AX7 (like,
say the ECC803s that tubedepot only wants $700 for).

If your preamp has AC filaments, you'd be better off sticking
with 6EU7 as the whole purpose behind 6EU7 was to minimize
filament hum pickup so OEM's wouldn't have to spend money
on DC filament supplies.

OTOH, there's an awful lot more selection of current
production 12AX7 than 6EU7.

--
Ned Carlson Triode Electronics Chicago,IL USA
www.triodeelectronics.com