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Patrick Turner Patrick Turner is offline
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Default Utralinear SE amps with EL34/6CA7.

Its a little known fact that one may take advantage of the UL
connection even when you don't like to.

Most ppl think the UL connection for EL34 always means 43% screen
taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.

With pure class A1 PP amps or SE class A1 amps there is no reason why
ppl should not use UL taps at 75% of the P turns.
One might say well the triode connection is the best but you'll only
get about 6W from an EL34 in triode. The power output is rarely more
than 27% of power input because the Ea minimum swing is restricted by
the onset of grid current. But when you look at the load lines you can
see that one could swing a bit further if you had the tube in pentode
and get 9W from 24W of idle power.
Well, To get the swing you need, try screen taps up to 75%.
The Ra will then be about 2k which is not much above triode Ra of
1,250 ohms.
And RL can be say about 5k, so the DF is still OK, and linearity
virtually equal to triodes.

I have tried this trick in conjunction with CFB windings where the CFB
= 12.5% and UL taps are at 62.5% of the total P turns. If the OPT has
5K:5 ohm ratio, you get Rout = 1.1 ohm.
Overall gain is then like a 300B, about 4.5, Va-k divided by Vg-0V.
About 48Vrms to the grid is needed for clipping.
I get 8.5W with Ea = 350V, Ia + Ig2 = Ik = 66mA. Distortion is
virtually all 2H until near clipping.


Patrick Turner.
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Andre Jute[_2_] Andre Jute[_2_] is offline
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Default Utralinear SE amps with EL34/6CA7.

On Mar 29, 3:34*pm, Patrick Turner wrote:
Its a little known fact that one may take advantage of the UL
connection even when you don't like to.

Most ppl think the UL connection for EL34 always means 43% screen
taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.

With pure class A1 PP amps or SE class A1 amps there is no reason why
ppl should not use UL taps at 75% of the P turns.
One might say well the triode connection is the best but you'll only
get about 6W from an EL34 in triode. The power output is rarely more
than 27% of power input because the Ea minimum swing is restricted by
the onset of grid current. But when you look at the load lines you can
see that one could swing a bit further if you had the tube in pentode
and get 9W from 24W of idle power.
Well, To get the swing you need, try screen taps up to 75%.
The Ra will then be about 2k which is not much above triode Ra of
1,250 ohms.
And RL can be say about 5k, so the DF is still OK, and linearity
virtually equal to triodes.

I have tried this trick in conjunction with CFB windings where the CFB
= 12.5% and UL taps are at 62.5% of the total P turns. If the OPT has
5K:5 ohm ratio, you get Rout = 1.1 ohm.
Overall gain is then like a 300B, about 4.5, Va-k divided by Vg-0V.
About 48Vrms to the grid is needed for clipping.
I get 8.5W with Ea = 350V, Ia + Ig2 = Ik = 66mA. Distortion is
virtually all 2H until near clipping.

Patrick Turner.


Clever, this, Patrick, for those who can wind their own iron. Those of
us who have buy our iron out of a catalogue have to be satisfied with
half your power. From
http://www.audio-talk.co.uk/fiultra/...0ON%20AMPS.htm
we have this simple SE EL34 integrated linestage built with only
three valves (envelopes, actually, as there are in total four valves)
to drive an efficient speakers (also shown at the above site):
http://www.audio-talk.co.uk/fiultra/...L34-SEntry.jpg

More power to your arm, pal.

Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review
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Watt? Me worry? Watt? Me worry? is offline
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Posts: 58
Default Utralinear SE amps with EL34/6CA7.

On Mar 29, 2:20�pm, Andre Jute wrote:
On Mar 29, 3:34�pm, Patrick Turner wrote:





Its a little known fact that one may take advantage of the UL
connection even when you don't like to.


Most ppl think the UL connection for EL34 always means 43% screen
taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.


With pure class A1 PP amps or SE class A1 amps there is no reason why
ppl should not use UL taps at 75% of the P turns.
One might say well the triode connection is the best but you'll only
get about 6W from an EL34 in triode. The power output is rarely more
than 27% of power input because the Ea minimum swing is restricted by
the onset of grid current. But when you look at the load lines you can
see that one could swing a bit further if you had the tube in pentode
and get 9W from 24W of idle power.
Well, To get the swing you need, try screen taps up to 75%.
The Ra will then be about 2k which is not much above triode Ra of
1,250 ohms.
And RL can be say about 5k, so the DF is still OK, and linearity
virtually equal to triodes.


I have tried this trick in conjunction with CFB windings where the CFB
= 12.5% and UL taps are at 62.5% of the total P turns. If the OPT has
5K:5 ohm ratio, you get Rout = 1.1 ohm.
Overall gain is then like a 300B, about 4.5, Va-k divided by Vg-0V.
About 48Vrms to the grid is needed for clipping.
I get 8.5W with Ea = 350V, Ia + Ig2 = Ik = 66mA. Distortion is
virtually all 2H until near clipping.


Patrick Turner.


Clever, this, Patrick, for those who can wind their own iron. Those of
us who have buy our iron out of a catalogue have to be satisfied with
half your power. From
�http://www.audio-talk.co.uk/fiultra/...0ON%20AMPS.htm
�we have this simple SE EL34 integrated linestage built with only
three valves (envelopes, actually, as there are in total four valves)
to drive an efficient speakers (also shown at the above site):
�http://www.audio-talk.co.uk/fiultra/...L34-SEntry.jpg

More power to your arm, pal.

Andre Jute
Visit Jute on Amps at
�http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review- Hide quoted text -

- Show quoted text -



Hi RATs!

Yes, trying to make it loud using the amplifier is just another way to
waste as much time and money as is available

Power output is measured using a steady signal, either Sin wave or
white noise. A constant signal allows accurate measurement.

Music is, at least in the olden times, was, not a constant signal.

This is where the two major politcal parties of the audio arena
diverge. Do we want accurate information or beautiful Music. Both
sides assume they know the truth. We will never know the truth. We are
human, not smart

My EL34 amp was UL, factory. It is now triode, with a diode and an R
between Plate and Screen. The Z of the OPT is now much greater than
optimal for max power output. It does sound really good

And the classic EL34/6CA7 has been replaced by 6BQ6-GTB, further
reducing power output. Oh, the horror 8*P

It does sound really, really good.

None of us knows everything, but, some of us just do whatever sounds
"nice".

Life ain't a Force March for everyone, some of us Samba.

Ole!

Happy Ears!

Al



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Patrick Turner Patrick Turner is offline
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Default Utralinear SE amps with EL34/6CA7.

On Mar 30, 10:49*pm, "Watt? Me worry?" wrote:
On Mar 29, 2:20 pm, Andre Jute wrote:





On Mar 29, 3:34 pm, Patrick Turner wrote:


Its a little known fact that one may take advantage of the UL
connection even when you don't like to.


Most ppl think the UL connection for EL34 always means 43% screen
taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.


With pure class A1 PP amps or SE class A1 amps there is no reason why
ppl should not use UL taps at 75% of the P turns.
One might say well the triode connection is the best but you'll only
get about 6W from an EL34 in triode. The power output is rarely more
than 27% of power input because the Ea minimum swing is restricted by
the onset of grid current. But when you look at the load lines you can
see that one could swing a bit further if you had the tube in pentode
and get 9W from 24W of idle power.
Well, To get the swing you need, try screen taps up to 75%.
The Ra will then be about 2k which is not much above triode Ra of
1,250 ohms.
And RL can be say about 5k, so the DF is still OK, and linearity
virtually equal to triodes.


I have tried this trick in conjunction with CFB windings where the CFB
= 12.5% and UL taps are at 62.5% of the total P turns. If the OPT has
5K:5 ohm ratio, you get Rout = 1.1 ohm.
Overall gain is then like a 300B, about 4.5, Va-k divided by Vg-0V.
About 48Vrms to the grid is needed for clipping.
I get 8.5W with Ea = 350V, Ia + Ig2 = Ik = 66mA. Distortion is
virtually all 2H until near clipping.


Patrick Turner.


Clever, this, Patrick, for those who can wind their own iron. Those of
us who have buy our iron out of a catalogue have to be satisfied with
half your power. From
http://www.audio-talk.co.uk/fiultra/...0ON%20AMPS.htm
we have this simple SE EL34 integrated linestage built with only
three valves (envelopes, actually, as there are in total four valves)
to drive an efficient speakers (also shown at the above site):
http://www.audio-talk.co.uk/fiultra/...L34-SEntry.jpg


More power to your arm, pal.


Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review- Hide quoted text -


- Show quoted text -


Hi RATs!

Yes, trying to make it loud using the amplifier is just another way to
waste as much time and money as is available

Power output is measured using a steady signal, either Sin wave or
white noise. A constant signal allows accurate measurement.

Music is, at least in the olden times, was, not a constant signal.

This is where the two major politcal parties of the audio arena
diverge. Do we want accurate information or beautiful Music. Both
sides assume they know the truth. We will never know the truth. We are
human, not smart

My EL34 amp was UL, factory. It is now triode, with a diode and an R
between Plate and Screen. The Z of the OPT is now much greater than
optimal for max power output. It does sound really good


Hi Al,

What ya hiding here with this business of a DIODE plus screen stopper
resistor between anode and screen???

Just wtf does the diode actually do, in your own words, in your own
time?

Patrick Turner.

And the classic EL34/6CA7 has been replaced by 6BQ6-GTB, further
reducing power output. Oh, the horror 8*P

It does sound really, really good.

None of us knows everything, but, some of us just do whatever sounds
"nice".

Life ain't a Force March for everyone, some of us Samba.

Ole!

Happy Ears!

Al- Hide quoted text -

- Show quoted text -


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Watt? Me worry? Watt? Me worry? is offline
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Posts: 58
Default Utralinear SE amps with EL34/6CA7.

On Mar 30, 9:37�pm, Patrick Turner wrote:
On Mar 30, 10:49�pm, "Watt? Me worry?" wrote:





On Mar 29, 2:20 pm, Andre Jute wrote:


On Mar 29, 3:34 pm, Patrick Turner wrote:


Its a little known fact that one may take advantage of the UL
connection even when you don't like to.


Most ppl think the UL connection for EL34 always means 43% screen
taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.


With pure class A1 PP amps or SE class A1 amps there is no reason why
ppl should not use UL taps at 75% of the P turns.
One might say well the triode connection is the best but you'll only
get about 6W from an EL34 in triode. The power output is rarely more
than 27% of power input because the Ea minimum swing is restricted by
the onset of grid current. But when you look at the load lines you can
see that one could swing a bit further if you had the tube in pentode
and get 9W from 24W of idle power.
Well, To get the swing you need, try screen taps up to 75%.
The Ra will then be about 2k which is not much above triode Ra of
1,250 ohms.
And RL can be say about 5k, so the DF is still OK, and linearity
virtually equal to triodes.


I have tried this trick in conjunction with CFB windings where the CFB
= 12.5% and UL taps are at 62.5% of the total P turns. If the OPT has
5K:5 ohm ratio, you get Rout = 1.1 ohm.
Overall gain is then like a 300B, about 4.5, Va-k divided by Vg-0V.
About 48Vrms to the grid is needed for clipping.
I get 8.5W with Ea = 350V, Ia + Ig2 = Ik = 66mA. Distortion is
virtually all 2H until near clipping.


Patrick Turner.


Clever, this, Patrick, for those who can wind their own iron. Those of
us who have buy our iron out of a catalogue have to be satisfied with
half your power. From
http://www.audio-talk.co.uk/fiultra/...0ON%20AMPS.htm
we have this simple SE EL34 integrated linestage built with only
three valves (envelopes, actually, as there are in total four valves)
to drive an efficient speakers (also shown at the above site):
http://www.audio-talk.co.uk/fiultra/...L34-SEntry.jpg


More power to your arm, pal.


Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review- Hide quoted text -


- Show quoted text -


Hi RATs!


Yes, trying to make it loud using the amplifier is just another way to
waste as much time and money as is available


Power output is measured using a steady signal, either Sin wave or
white noise. A constant signal allows accurate measurement.


Music is, at least in the olden times, was, not a constant signal.


This is where the two major politcal parties of the audio arena
diverge. Do we want accurate information or beautiful Music. Both
sides assume they know the truth. We will never know the truth. We are
human, not smart


My EL34 amp was UL, factory. It is now triode, with a diode and an R
between Plate and Screen. The Z of the OPT is now much greater than
optimal for max power output. It does sound really good


Hi Al,

What ya hiding here with this business of a DIODE plus screen stopper
resistor between anode and screen???

Just wtf does the diode actually do, in your own words, in your own
time?

Patrick Turner.





And the classic EL34/6CA7 has been replaced by 6BQ6-GTB, further
reducing power output. Oh, the horror 8*P


It does sound really, really good.


None of us knows everything, but, some of us just do whatever sounds
"nice".


Life ain't a Force March for everyone, some of us Samba.


Ole!


Happy Ears!


Al- Hide quoted text -


- Show quoted text -- Hide quoted text -


- Show quoted text -- Hide quoted text -

- Show quoted text -


Hi RATs!

The diode prevents the screen from going the wrong way or something.
Someone said they liked the sound, so I tried it. It sounds better. No
clue why.

I use big 40A 1000V Ultrafast units. It was the only size the store
had four of...

Happy Ears!

Al






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Andre Jute[_2_] Andre Jute[_2_] is offline
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Posts: 631
Default Utralinear SE amps with EL34/6CA7.

On Mar 31, 3:37*am, Patrick Turner wrote:
On Mar 30, 10:49*pm, "Watt? Me worry?" wrote:





On Mar 29, 2:20 pm, Andre Jute wrote:


On Mar 29, 3:34 pm, Patrick Turner wrote:


Its a little known fact that one may take advantage of the UL
connection even when you don't like to.


Most ppl think the UL connection for EL34 always means 43% screen
taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.


With pure class A1 PP amps or SE class A1 amps there is no reason why
ppl should not use UL taps at 75% of the P turns.
One might say well the triode connection is the best but you'll only
get about 6W from an EL34 in triode. The power output is rarely more
than 27% of power input because the Ea minimum swing is restricted by
the onset of grid current. But when you look at the load lines you can
see that one could swing a bit further if you had the tube in pentode
and get 9W from 24W of idle power.
Well, To get the swing you need, try screen taps up to 75%.
The Ra will then be about 2k which is not much above triode Ra of
1,250 ohms.
And RL can be say about 5k, so the DF is still OK, and linearity
virtually equal to triodes.


I have tried this trick in conjunction with CFB windings where the CFB
= 12.5% and UL taps are at 62.5% of the total P turns. If the OPT has
5K:5 ohm ratio, you get Rout = 1.1 ohm.
Overall gain is then like a 300B, about 4.5, Va-k divided by Vg-0V.
About 48Vrms to the grid is needed for clipping.
I get 8.5W with Ea = 350V, Ia + Ig2 = Ik = 66mA. Distortion is
virtually all 2H until near clipping.


Patrick Turner.


Clever, this, Patrick, for those who can wind their own iron. Those of
us who have buy our iron out of a catalogue have to be satisfied with
half your power. From
http://www.audio-talk.co.uk/fiultra/...0ON%20AMPS.htm
we have this simple SE EL34 integrated linestage built with only
three valves (envelopes, actually, as there are in total four valves)
to drive an efficient speakers (also shown at the above site):
http://www.audio-talk.co.uk/fiultra/...L34-SEntry.jpg


More power to your arm, pal.


Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review- Hide quoted text -


- Show quoted text -


Hi RATs!


Yes, trying to make it loud using the amplifier is just another way to
waste as much time and money as is available


Power output is measured using a steady signal, either Sin wave or
white noise. A constant signal allows accurate measurement.


Music is, at least in the olden times, was, not a constant signal.


This is where the two major politcal parties of the audio arena
diverge. Do we want accurate information or beautiful Music. Both
sides assume they know the truth. We will never know the truth. We are
human, not smart


My EL34 amp was UL, factory. It is now triode, with a diode and an R
between Plate and Screen. The Z of the OPT is now much greater than
optimal for max power output. It does sound really good


Hi Al,

What ya hiding here with this business of a DIODE plus screen stopper
resistor between anode and screen???

Just wtf does the diode actually do, in your own words, in your own
time?

Patrick Turner.





And the classic EL34/6CA7 has been replaced by 6BQ6-GTB, further
reducing power output. Oh, the horror 8*P


It does sound really, really good.


None of us knows everything, but, some of us just do whatever sounds
"nice".


Life ain't a Force March for everyone, some of us Samba.


Ole!


Happy Ears!


Al- Hide quoted text -


- Show quoted text -


Yeah, I wondered about Al's wildly placed (artistic?) diode, then
decided to say nothing. Who knows, April Fool's Day may come early in
Tube Garden Time. Hell, hi-fi is so wild and wonderful, Al might
actually have discovered The One True Faith. However that may be, I
was going to leave it to you or John to be the first to say anything
-- and perhaps look like curmudgeons when the Nobel Prize Committee
calls at La Casa Marcy... Or maybe that will be the I. G. Noble Prize
Committee. Has it caught fire yet, Al?

Andre Jute
A little inaccuracy sometimes saves tons of explanation. --H.H.Munro
("Saki")(1870-1916)

Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review
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glenbadd glenbadd is offline
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Default Utralinear SE amps with EL34/6CA7.

On Apr 1, 3:01*am, "Watt? Me worry?" wrote:
On Mar 30, 9:37 pm, Patrick Turner wrote:

Hi RATs!

The diode prevents the screen from going the wrong way or something.
Someone said they liked the sound, so I tried it. It sounds better. No
clue why.

I use big 40A 1000V Ultrafast units. It was the only size the store
had four of...

Happy Ears!

Al


It may have originated from here http://oestex.com/tubes/
  #8   Report Post  
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Watt? Me worry? Watt? Me worry? is offline
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Posts: 58
Default Utralinear SE amps with EL34/6CA7.

Hi RATs!

Yes, the origin was Oz. That much I remember. But the emailer was not
Grim at all.

I do not think polarity matters, in this case, because it works in the
Southern hemisphere and the Northern hemisphere.

I have no serious problems. Well, mortality, but that is looking more
and more attractive

Here in Texas the duly elected State Board of Edumucation demands
American History textbooks for public high schools do not mention
Thomas Jefferson (guy wrote the Dec of Ind) but require equal billing
for Abe Lincoln and Jefferson Davies, the only president of the
Confederacy. The wind and sand and heat in West Texas are hard on the
eyes and such.

Like humans everywhere, they think where they live makes them special.
But, like too many, they think they are the only special people.

Anyway, I enjoy playing with circuits and listening to Music.

Test tones were fun for a bit, but, I gave them up after a few
years

Traded my A440 box for some opt iron 8*D

Gave the Distortion Analyzer away.

It is possible to have fun without having accurate numbers to back up
my BS

Happy April Fool's Day.

Al




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Tom Schlangen Tom Schlangen is offline
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Default Utralinear SE amps with EL34/6CA7.

Hi Patrick

Most ppl think the UL connection for EL34 always means 43% screen taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.


Yeah, and most winders wholeheartily will agree that 43% percent is ideal
because it is just the end of the 4th winding block of a 7-way
interleaved design (means 14-way interleave for PP), hence easily to
manufacture. Same with 50%, 40%, 33% and 25% (depending on number of
interleaves).

So much on "magic UL% numbers", honi soit qui mal y pense (I don't mean
you personally).

Regards,

Tom Schlangen
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Patrick Turner Patrick Turner is offline
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Default Utralinear SE amps with EL34/6CA7.

On Apr 1, 7:53*pm, flipper wrote:
On Wed, 31 Mar 2010 18:22:55 -0700 (PDT), glenbadd





wrote:
On Apr 1, 3:01*am, "Watt? Me worry?" wrote:
On Mar 30, 9:37 pm, Patrick Turner wrote:


Hi RATs!


The diode prevents the screen from going the wrong way or something.
Someone said they liked the sound, so I tried it. It sounds better. No
clue why.


I use big 40A 1000V Ultrafast units. It was the only size the store
had four of...


Happy Ears!


Al


It may have originated from herehttp://oestex.com/tubes/


I was thinking the same thing. In particular, on this page

http://oestex.com/tubes/oes.html

I read that ages ago but unless my eyeballs are installed backwards,
or something, that author has a serious problem with polarity and
'electron flow'.- Hide quoted text -


I tried fitting my eyeballs in differently and even with one facing
backwards and one facing forwards but I still could not see much
benefit to using all those different ac and dc voltages applied via
diodes to g2 and g3.

So what happens with beam tetrodes where the beam forming plates are
connected to the cathode?
I guess you don't get a chance to use these plates as one might use g3
in a pentode.
But then the gm of g3 is rather low and ineffective and non
linear....


The other day I did put a CRO on the screen to look at the screen
current in the 220 ohms stopper resistor in my SE35 with acoustical
CFB. At low levels the screen current ac is quite linear but at higher
levels approaching max there is up to 20% 2H in the signal just before
clipping occurs. I seemed to me the screen current was always only in
ONE direction, ie, electrons flowing into the positive screen supply
as is does at the anode. Conventional current flow is from positive to
negtive. A series diode in the anode circuit pointing into the anode
allows flow. allows averlam
So the diodes placed the way they are shown for g2 would just allow
screen current all the time in one direction and I cannot think why it
would want to flow the other way.

I'm very suspicious of the validity of the claims at that oestex site.

Patrick Turner.






- Show quoted text -




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Patrick Turner Patrick Turner is offline
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Default Utralinear SE amps with EL34/6CA7.

On Apr 2, 7:20*am, Tom Schlangen wrote:
Hi Patrick

Most ppl think the UL connection for EL34 always means 43% screen taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.


Yeah, and most winders wholeheartily will agree that 43% percent is ideal
because it is just the end of the 4th winding block of a 7-way
interleaved design (means 14-way interleave for PP), hence easily to
manufacture. Same with 50%, 40%, 33% and 25% (depending on number of
interleaves).

So much on "magic UL% numbers", honi soit qui mal y pense (I don't mean
you personally).

Regards,

Tom Schlangen


Well I agree entirely that recipes for UL OPTs had the primary = 14
layers and you could then build up the bobbin from its bottom with 4P
layers, one secondary section, 3P layers, CT, 3P layers, secondary
section, 4P layers.
This gave a PSPSP interleaving pattern. Designs like this were
publicised and analysed in Wireless World in the 1950s. And why such
crap was analysed and considered fit for audiophiles I don't know.

But it turns out that if you draw a graph of Ra vs UL tap %, then
you'll find a rapidly falling Ra until about 43% and then gradual
additional reduction of Ra until you get to 100% UL which is triode
connected.
So the 43% was at the knee of a curve. It worked well considering that
peple wanted some reasonably high gain because most designs
incorporated GNFB of up to 30dB in many cases. Remember the days when
there were wars over who could get the lowest distortion figures like
say 0.03% at 1dB below clipping?

A Williamson triode amp gave 1% at near clipping without GNFB. With
20db GNfB this 1% reduces to 0.1%, and with 30dB it would be 0.03%,
and one has to have a very wide BW OPT to get this and understand how
to apply phase tweaking circuits to make the amp stable
unconditionally. Makers now don't use wide band OPTs and they know
**** all about "critical damping". Past arts have been forgotten.

If you read RDH4 on the comparison of 3 watts from a 2A3 or from a
6F6, the harmonics production of the 6F6 is utterly appalling compared
to the triode. The UL does a lot to reduce the crap. But I like more
than 43%. In class A circuits where the load line is near horizontal
and one does not need to make the Ea min swing down much more than it
does with triode in class A1. But its useful if you can get the extra
swing. And you don't need to move the screen tap very far away from
the anode to get the extra swing, and with say taps at 60% to 75% the
tube behaves very much like a triode with very little 3H and other
higher H. Its not a problem if the gain is low with EL34. Even triode
gain is OK. 6550 also give very near full tetrode power when using 60%
screen taps. Manley Labs have EL34 with 25% UL and Ea = Eg2 = 550V.
I don't know why they bother with only 25%. But then they try to
squeeze many watts as possible; it is good for sales but not so hot
for fidelity or reliability.

Patrick Turner.

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Hi RATs!

OK, April Fool's Day has past.

Happy Ears!

Al Marcy

TX





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Tom wrote:

Most ppl think the UL connection for EL34 always means
43% screen taps.
This % was always regarded as optimal because triode like
THD is
achieved and Rout reduced to give Rout = RL. But this was
mainly for
class AB PP amps.


Yeah, and most winders wholeheartily will agree that 43%
percent is ideal
because it is just the end of the 4th winding block of a
7-way
interleaved design (means 14-way interleave for PP), hence
easily to
manufacture. Same with 50%, 40%, 33% and 25% (depending on
number of
interleaves).

So much on "magic UL% numbers", honi soit qui mal y pense
(I don't mean
you personally).


As originally coined, the term "ultralinear" applies to an
optimum. If it isn't at that optimum ratio, it isn't UL. So
it seems to me, anyway. Patrick's imaginary "most people"
are possibly quite right.

"25% screen tap" is a clearer and more accurate description
than "25% UL", and isn't much harder to write.

Thing is, if we conspire to trash the meaning of
"ultralinear", then we lose an important distinction in our
language, and get nothing in return, just because some folk
think that jargon adds grandeur to their tedium.

More gain allows more feedback. Other than UL, where you put
your screen tap is Hobson's Choice when it comes to final
THD, surely?

However, it could be that, if you chose a particular
harmonic, or blend of harmonics, rather than THD, you might
find a different optimum power/distortion ratio at some
different screen tap ratio. That might be a bit interesting.
UL(3H+5H) might be a good idea.

Al's getting dafter, incidentally. Al, wake up! Everyone
needs power.

Roughly in proportion to room size, speaker technology, and
the number of friends you've got.

So wrote I.

Yearning for the glory days of plain text.


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On Apr 2, 11:55*am, "Ian Iveson"
wrote:
Al's getting dafter, incidentally. Al, wake up! Everyone

needs power.

Roughly in proportion to room size, speaker technology, and
the number of friends you've got.

So wrote I.

Yearning for the glory days of plain text.- Hide quoted text -

- Show quoted text -


Hi RATs!

My speakers are about 95dB/W/M. My room is 12'x16'x8'. Friends? Not
many that visit, often. I have been in bed for over twelve years

Yes, the Teletype was upper case only. Lower case was the thin edge of
the wedge...

Sigh.

Happy Ears!
Al

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flipper wrote:

The diode prevents the screen from going the wrong way
or something.
Someone said they liked the sound, so I tried it. It
sounds better. No
clue why.

I use big 40A 1000V Ultrafast units. It was the only
size the store
had four of...


It may have originated from here http://oestex.com/tubes/


I was thinking the same thing. In particular, on this page

http://oestex.com/tubes/oes.html

I read that ages ago but unless my eyeballs are installed
backwards,
or something, that author has a serious problem with
polarity and
'electron flow'.


Obviously you don't know much about the darkness.

All non-linearity in electronic devices arises from their
interaction with dark matter, via dark currents and dark
voltages. The sum of interactions is perfectly linear, but
the proportion of dark interaction is not. Hence, if leakage
to the dark world can be reduced, then the result is greater
linearity in the perceived world.

Although a reverse-connected diode is a poor relation to the
ideal dark edoid, or anti-diode, it does reduce the
modulation of the dark field, by keeping some of the dark
charge in.

Ian




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Al wrote:

My speakers are about 95dB/W/M. My room is 12'x16'x8'.
Friends? Not
many that visit, often. I have been in bed for over twelve
years


I prescribe at least 600W, Al, with midi keyboard, synths,
plenty FX, and a sequencer on your 'puter. Take a walk on
the wild side.

Yes, the Teletype was upper case only. Lower case was the
thin edge of
the wedge...


Quite. I knew where I was then, AFAIR.

Sigh.


Alas...and we had the world at its prime.

My newsreader used to put those chevrons in all by itself.
**** knows where history is taking us now.

Ian


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On Apr 2, 1:18�pm, "Ian Iveson"
wrote:
Al wrote:
My speakers are about 95dB/W/M. My room is 12'x16'x8'.
Friends? Not
many that visit, often. I have been in bed for over twelve
years


I prescribe at least 600W, Al, with midi keyboard, synths,
plenty FX, and a sequencer on your 'puter. Take a walk on
the wild side.

Yes, the Teletype was upper case only. Lower case was the
thin edge of
the wedge...


Quite. I knew where I was then, AFAIR.

Sigh.


Alas...and we had the world at its prime.

My newsreader used to put those chevrons in all by itself.
**** knows where history is taking us now.

Ian


History brought and brings us here and now. We get old and everybody
else runs around like there is a fire, somewhere

The world is OK, but, the Internet is in a snit, for the fun of it?

Al

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"Patrick Turner" wrote in message
...
It seemed to me the screen current was always only in
ONE direction, ie, electrons flowing into the positive screen supply
as is does at the anode. Conventional current flow is from positive to
negtive. A series diode in the anode circuit pointing into the anode
allows flow. allows averlam
So the diodes placed the way they are shown for g2 would just allow
screen current all the time in one direction and I cannot think why it
would want to flow the other way.

I'm very suspicious of the validity of the claims at that oestex site.

Patrick Turner.

Alex:
The only way the current n the screen grid can reverse is the secondary
emission from the screen grid. For this to happen, the tube shall be a
tetrode with VpVg2 or a pentode with Vg3 Vg2. If g2 has a pronounced and
consistent secondary emission, then Vg2 voltage will tend to rise (jump
because of the diodes) to about 20...50V below the plate (tetrode case) or
below g3 (which is nearly connected to plate in these odd circuits). Thus g2
will be tracking plate with no g2 net current!!!!!

However I do not think one can dependably rely or reliably depend on the
secondary emission from g2.

And of course, if the beamformer plates or g3 is connected to the cathode,
this will not work at all. And majority of the output tubes do have g3 or
beamformers connected to cathode.







- Show quoted text -



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On Apr 4, 5:11*pm, "Alex" wrote:
"Patrick Turner" wrote in message

...
*It seemed to me the screen current was always only in
ONE direction, ie, electrons flowing into the positive screen supply
as is does at the anode. Conventional current flow is from positive to
negtive. A series diode in the anode circuit pointing into the anode
allows flow. allows *averlam
So the diodes placed the way they are shown for g2 would just allow
screen current all the time in one direction and I cannot think why it
would want to flow the other way.

I'm very suspicious of the validity of the claims at that oestex site.

Patrick Turner.

Alex:
The only way the current n the screen grid can reverse is the secondary
emission from the screen grid. For this to happen, the tube shall be a
tetrode with VpVg2 or a pentode with Vg3 Vg2. If g2 has a pronounced and
consistent secondary emission, then Vg2 voltage will tend to rise (jump
because of the diodes) to about 20...50V below the plate (tetrode case) or
below g3 (which is nearly connected to plate in these odd circuits). Thus g2
will be tracking plate with no g2 net current!!!!!

However I do not think one can dependably rely or reliably depend on the
secondary emission from g2.

And of course, if the beamformer plates or g3 is connected to the cathode,
this will not work at all. And majority of the output tubes do have g3 or
beamformers connected to cathode.





- Show quoted text -- Hide quoted text -


- Show quoted text -


I cannot observing evidence of g2 secondary emissions.

Patrick Turner.
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Al wrote:

History brought and brings us here and now. We get old and
everybody
else runs around like there is a fire, somewhere



Exactly. I was wondering why folk are celebrating quick
deliveries. What's such a rush that it's worth laying off
the warehouse workers, then wiring up the postmen and
turning them into robots? Then the suppliers discover that
unemployed people and robots don't order their stuff so
there's a crisis that must be China's fault, however,
meanwhile, the robot postmen have got holes in their socks
and their gadgets, for want of maintenance, have begun to
malfunction.

Many years ago, a letter or small package sent to and from
an English town up to 10pm would arrive at its destination
before 8am, having travelled by steam-train and Royal Mail
van. It was delivered by a proper, sullen, treadweary
homosapiens-style public-service postman with dogbitten
fingers, when he wasn't on strike.

The world is OK, but, the Internet is in a snit, for the
fun of it?


Unbridled socialism was bad enough when it was creeping. A
world-wide web seems to me like an impending disaster.

Ian




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Alex:
The only way the current n the screen grid can reverse is the secondary
emission from the screen grid. For this to happen, the tube shall be a
tetrode with VpVg2 or a pentode with Vg3 Vg2. If g2 has a pronounced
and
consistent secondary emission, then Vg2 voltage will tend to rise (jump
because of the diodes) to about 20...50V below the plate (tetrode case) or
below g3 (which is nearly connected to plate in these odd circuits). Thus
g2
will be tracking plate with no g2 net current!!!!!

However I do not think one can dependably rely or reliably depend on the
secondary emission from g2.

And of course, if the beamformer plates or g3 is connected to the cathode,
this will not work at all. And majority of the output tubes do have g3 or
beamformers connected to cathode.


P. Turner:
I cannot observing evidence of g2 secondary emissions.

Patrick Turner.

Alex:
Which power tetrode did you use for the experiment? Or which pentode with g3
connected to plate? ( I do not have a tetrode to experiment.) Note that
there will be no secondary emission current in a conventional pentode or
beam tetrode with g3 or beamformer connected to cathode, so EL84 or 6V6 will
not exhibit any secondary emission from g2.

Generally I would think that secondary emission from g2 is possible (as from
the plate) but it is not consistent enough to build a circuit around it.


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On Apr 5, 1:09*pm, "Ian Iveson"
wrote:


/snip


Unbridled socialism was bad enough when it was creeping. A
world-wide web seems to me like an impending disaster.

Ian


The rise in the human population is the only real disaster, but not
pending, not even im... We cannot find jobs, but, we can find someone
to make more babies.

Too bad headcount doesn't count for anything, huh? Well, unless you
choose to play Ghenghis Khan... what a wonderful Leader he was. Not
the first, nor the last, to pretend destruction is a good thing.

Happy Ears!

Al

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On Apr 8, 8:47*am, flipper wrote:

TheN go complain about it in the African or Latin American continents
newsgroups because population growth is not a 'problem' in
industrialized nations.


Hi RATs!

OK, OK, we do not have too many people, just not enough jobs...
pretense is all in the phrasing. There is no problem we cannot deny

Happy Ears!

Al

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On Apr 9, 1:57*pm, flipper wrote:
On Thu, 8 Apr 2010 15:27:32 -0700 (PDT), "Watt? Me worry?"

wrote:
On Apr 8, 8:47*am, flipper wrote:


TheN go complain about it in the African or Latin American continents
newsgroups because population growth is not a 'problem' in
industrialized nations.


Hi RATs!


OK, OK, we do not have too many people, just not enough jobs...
pretense is all in the phrasing.


Not "pretense." More like nonsensical spin.

We did not 'over populate into a recession'. The cause is elsewhere.

The vast majority were employed before the recession (where were the
'too many babies' then?) so, unless you're proposing to assassinate
those without a job to make the unemployment figures look better,
specious claims like 'it's a population problem' contributes nothing.

There is no problem we cannot deny


Speak for yourself, paleface (Tonto to the Lone Ranger's comment
"we're in trouble now" when surrounded by 1,000 hostile 'Indians')


The world is rapidly becoming dominated by humans. We are even
changing the weather.
If we double world population and everyone expects to have a standard
of living equal to the average North American standards, then where
will the resources come from? where will the food and water come from?
I guess we can afford to cause the extinction of 3/4 of all known
plant and animal species just so we can get food and minerals and
materials for our use. But by saying population doubling most people
think about the next 50 or 100 years. But what of another 1,000 years,
or 10,000years? Such time spreads are quite small compared to how it
took before modern life became possible with McDonald's golden arches,
dentists and the Pill.

Now by about 1800, the world looked like there would always be
limitless resources. At that time and most people didn't live very
long or use much stuff in their short lifetimes.
Louis the 14th may well have spent up bigtime at Versailles, but him
and his entourage were a tiny fraction of that world.
But now everyone wants to live like a little king, queen, prince or
princess.

Everyone wants too much.

I gotta tellya, the Earth can kick back !!!!!!

I think you should read the latest book by James Lovelock, The Revenge
of Gaia. Also see
http://www.newscientist.com/article/...e-mankind.html

Apart from living on $10,000 per anum and never having any kids, there
isn't anything you can legally do to prevent the worst things of
future from happening.


Patrick Turner




Happy Ears!


Al- Hide quoted text -


- Show quoted text -


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Al wrote:

The rise in the human population is the only real disaster,
but not
pending, not even im... We cannot find jobs, but, we can
find someone
to make more babies.


We just need to make smaller babies. If we were half the
height, we'd need just an eighth of the resources.

Too bad headcount doesn't count for anything, huh? Well,
unless you
choose to play Ghenghis Khan... what a wonderful Leader he
was. Not
the first, nor the last, to pretend destruction is a good
thing.


Culling doesn't work for long coz it puts the birthrate up,
and increases the cost of labour. Pensions are very
effective, but they seem to need economic growth and an
advanced industrial society.

Ian


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