[Trevor Wilson]

"Andre Jute" wrote in message
oups.com...
I really don't know why you bother with Wilson. He is incorrigible. The
mindless man takes the joke about NFB in my sig seriously and builds
monstrous flame wars on it,

**Nope. I just correct your errors and your lies. Nothing more.

and when I make jokes about germanium and
the founder of Fairchild, he takes that too as serious proof of
ignorance of transistors (or perhaps he doesn't know germanium is
obsolete or why Fairchild is important?).

**Incorrect, on both points. I cut my teeth on germanium transistors. I
still have my prized 2N301, which I paid an absolute fortune for. It was a
wonderous thing for a young schoolboy. I had no idea that transistors got
warm, 'till I started mucking about with my 2N301. Unlike a slew of AC128s,
it was not destroyed by my ignorance.

He simply cannot understand
that I am indifferent to transistors;

**I understand that you are ignorant of their capabilities.

it is not a state of mind he
permits. Trevor Wilson is another pork butcher insisting on his right
to set up a pig abattoir in a synagogue. He simply doesn't permit
anyone else to have an individual choice.

**Also incorrect. I do not permit liars to promulgate their lies.

You can't explain anything to
anyone with Wilson's mindset. He has no right to any more of my time or
my patience;

**Huh? This is the second time you've used such words in this thread. Here's
a tip for you: Don't threaten, just do. Otherwise, you just like like an
impotent moron. Alternatively, you COULD engage in a proper and honest
discussion. As if that ever interested you.

as Al Marcy says, no one has a duty to explain. I'm out of
it.

**And again with the hollow threats.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Andre Jute]

Patrick Turner wrote to Trevor Wilson:

Your lack of understanding of the basics would prevent you ever designing
anything.

You are not alone.

Many here on the group almost know nothing, but cannot resist taking part in
discussions.

If only such people were open to questioning of their own BS.

Some of us feel a great need to mop up after the mess they leave.

Patrick Turner.

Mostly I feel like a shower.

All the same, we can't make an entry qualification, we must always be
open newbies, etc. The good old ARRL codes would serve us well if we
were to make the effort to resurrect them.

But some people, easily spotted by their attitude, their unwillingness
to permit anyone else free choice, cannot be either saved or
instructed. After making all the effort goodwill to the hobby demands,
we must cut them loose by simply not responding to them.

Mind you, I am continually amazed at the guys who come to RAT and claim
to know everything. They don't even know that they lose out on the
pleasures of discovering new knowledge. I learn something almost every
week on RAT.

Andre Jute

[Eeyore]

Andre Jute wrote:

I really don't know why you bother

I've often thougt this about you too Mr Charlatan !

Graahm

[Eeyore]

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Anyone brave enought to try any drug with hallucinogenic properties will become
rapidly aware of the defects of subjective judgements.

Graham

[Eeyore]

Andre Jute wrote:

I am continually amazed at the guys who come to RAT and claim
to know everything.

Sure. You're the only one in your mind who can do that.

Graham

[Andre Jute]

The dumbass (pun! pun!) Eeyore, usually known as Graham "Poopie"
Stevenson, wrote:

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Let's see what I actually wrote:

"The key word is "perceived". It is one of those real psychoacoustic
phenomena the engineers try to pretend cannot happen."

Aha, that "the engineers try to pretend cannot happen."

QED.

I just didn't put it strongly enough. I should have written, "that the
lesser engineers will call psychotic."

Andre Jute
Stop bleating. Please, please, please give me the Silence of the Lambs.

[Eeyore]

Andre Jute wrote:

The dumbass (pun! pun!) Eeyore, usually known as Graham "Poopie"
Stevenson, wrote:

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Let's see what I actually wrote:

"The key word is "perceived". It is one of those real psychoacoustic
phenomena the engineers try to pretend cannot happen."

Aha, that "the engineers try to pretend cannot happen."

QED.

I just didn't put it strongly enough. I should have written, "that the
lesser engineers will call psychotic."

Andre Jute
Stop bleating. Please, please, please give me the Silence of the Lambs.

You're incapable of seeing the wood for the tress never mind making any
intelligent sonic judgement.

To your ears colouration = fidelity.

Graham

[Patrick Turner]

" wrote:

Patrick Turner wrote:

And the well educated and likable man who taught me how to build things
said the man who makes no mistakes makes nothing.

This puts me in mind of an analogy for error correction: Imagine a
guided missile..

It goes slightly off-course to the right, and corrects. Slightly to the
left and corrects, above, corrects, below, corrects... and so forth. No
error is allowed to continue, all errors are (presumably) kept to a
minimum.

Sounds a bit like NFB to me ;-)

An alternative is a ballistic missile... No guidance/NFB. Probably each
is equally effective at very short distances. The unguided version may
even be better in that case as it may substitute guidance systems for
explosive power. But otherwise...

Now, the NFB system is always in some sort of error-mode and/or
crossing over the singular axis-of-perfection. The non-guided system
will be entirely perfect, or will never be perfect.

Just a random thought.

My random thoughts rarely stray to blowing things up with/without NFB
and rocket science.

Albert Einstein thought a lot between sampling a string of various lovers in
his life.
He reckoned atomic weapons might curse the world soon after their invention,
so he wrote letters of warning to Polly Tishans, who never listened to
scientists' worries.

Now we still live with the threat, and that of all the other mistakes we are
making
in one huge rush of unsustainability and stupidity propelled by the ego of
every man and woman thinking
in ways only kings and queens could do in past ages.

There is no way our planet will survive if population rises to 10 billion
and they all live the north american lifestyle.
No need for americans to take that personally,
but there just isn't enough oil, timber, land, watwer etc, etc, etc,etc.

In 1,000 years, Planet Earth will be a very grim place if mistakes continue.

There will come a time when the biggest air con required for the home won't
be affordable.



Peter Wieck
Wyncote, PA

[Prune]

" wrote in news:1154111059.939212.316600
@s13g2000cwa.googlegroups.com:

Sounds a bit like NFB to me ;-)

Actuially, since you're feeding back just the error instead of the whole
signal, this is much more like Hawksford EC than typical NFB.

[Prune]

flipper wrote in
:

An "adequate answer?"

Forget about any, then.

I wasn't specific enough it seems. What I meant was that all I got in that
thread was criticism. And when I bring it up again, you accuse me of
having short memory. WTF? When I'm attacked like that, what else can I do
but respond in kind?

[Patrick Turner]

Trevor Wilson wrote:

"Patrick Turner" wrote in message
...

But you continue to make the idiotic comparison between triodes and
bjts
based
on entirely
false perceptions.

**So you keep saying.

And I need to repeat it ad nauseum because you have a mental block about
basic transistor behaviour.

**Er, no. BJTs are current amplification devices and need to be treated as
such. Any engineer wo treats them as a Voltage amplification device is
making a fundamental error.

But your parrot like answer does not address my criticism of you lack of
understanding
of bjts.

The turn on voltage between base and emitter for bjts when plotted against the
collector current
is not a linear relationship while the ratio of base input current to collector
current is a
linear relationship.

Series VOLTAGE NFB is used in countless bjt based output stages to overcome the
tragically POOR voltage linearity of bjts, and the emitter follower connection
does this well.

The linearity of voltage amplification in bjt based designs depends almost
entirely on the liberal use
of NFB in virtually each and every circuit one sees, with both local and global
etc.

Because the bjt is so non linear, we use shirtloads of NFB.

The non linearity is said not to matter because the NFB can act as the
correction agent.

Just try thinking about bjts being what they are, non linear voltage amps
dependant
on huge NFB amounts to linearize them and you'll be OK.

But trying to tell me BJTs are linear voltage devices is heresy to me.

That they are linear current devices is exploited, but the main type of NFB used
in
all bjt amplifiers is series voltage NFB, not series current NFB, and there
is a heck of a difference BTW.


We already know the input / output VOLTAGE linearity of any appropriate
triode
is better than a 2N3055.

**Well, as I have stated ad nauseum: A BJT is a current amplification
device. You MUST look at it's CURRENT amplification curve.

We can look at the current curves for weeks and nothing else,
but it does not tell us the relationship between
current output and the voltage change between base and emitter.

**That's because a BJT is a current amplification device, not a Voltage
amplification device.

No need to act like a parrot.

It is not convincing anyone that you can identify fully what the behavioural
characteristics of the typical bjt is.




We know that bjts have good current linearity.

**Finally, you understand. Now tell Jute.

You don't understand transistor basics.

**You seem to forget that I am the one explaining to everyone that a BJT is
a current amplification device. Others keep bleating on about Voltage
changes in the Base circuit of a transistor, then wondering why they don't
work correctly. It is a fundamental error.

But for base current to flow, there must be a voltage applied.

The base input impedance is non linear.

VOLTAGE NFB is the main weapon used against the non linear behaviour of
bjt voltage amplifying characteristiocs.
Usually there is a lot of series current NFB used to help the voltage linearity.

Without NFB the bjt is a horrible device to try to use.





Current linearity cannot be compared simply to voltage linearity.

**Why?

Because they are two different issues.

Tubes are voltage operated devices with no input current to the grid
during most normal operating conditions, like j-fets and mosfets.
So their current linearity is an irrelevant issue to consider.

Their voltage linearity is the important issue, ie the transconductance,
and the linearity of amps per volt with respect to anode or drain current.

But with bjts there can only be a tiny voltage movement between base and
emitter

to cause the whole current range from uamps to many amps.

**Which is why it is VERY IMPORTANT to treat them as current amplification
devices. Vary the Base current and measure the Collector current changes.

At each and every one of your statements in reply to me
you are making yourself look more like a galah.

Cannot you see that the gm change in a transistor for the applied voltage
between base and emitter
has a very non linear relationship with base to emitter voltage?

It is NFB that makes the bjt linear. The device is basically NON LINEAR.
There is a linear relationship between base current and collector current,
but the collector current has a non linear relationship with base to emitter
voltage applied.

I suggest you conduct tests on a breadboard to confirm what i am saying is true,
not false,
and that you have NOT got a grasp of the fundementals.


The relationship of gm change to collector current is a very non linear
one,
and is not graphed in the spec sheets because there is no need to.

**That's because BJTs are current amplification devices.




Its like comparing oranges to asperagus

**ONly if the designer is stupid enough to try to use a transistor in a
circuit which is the same as the one used for a Triode.

A transistor can sometimes be substituted in a circuit where a tube
operated.

**Not directly, it can't.

An MJE340 can be used where a 250V supply exists and it can do what
a 12AU7 or 6BX6 etc may have done.
The trouble with such a substitution is the input impedance of the base
which is

non linear and attrociously low,

**As long as the BJT is treated as a current amplification device, no
problem exists. Problems begin when foolish engineers try to treat BJTs are
Voltage amplification devices.

and the horrible non linearity of the MJE340
as a voltage amplifier compared to the tube. Its worse than the 6BX6
pentode.

**That's because a BJT is a current amplification device. And it's CURRENT
amplification curve is vastly more linear than any Pentode's gm curve.

But with a suitable emitter resistor forming a NFB current loop the MJE340
begins to produce a much more linear operation with THD comparable to the
tube
without any such current FB loop or other loop.
The input impedance is raised by the current NFB loop, but it is still
fairly
low.
If a second bjt is darlington connected ahead of the first MJE340, then
the
input
impedance is raised by a factor of about the hfe for the additional bjt.
This makes then makes the bjt have little effect on the preceeding stage,
and
load changes
at the output have little effect on the source VOLTAGE which must not be
allowed
to vary
due to bjt input current varying with load changes at the bjt output.

But I am sure you could work all this out for yourself if you spent next
sunday
in your shed playing with bjts to examine their BS behaviour and how to
tame it.

**No need. I did it all 30 years ago. I've been grappling with BJTs since
that time.

You just cannot understand bjt operation NOW.
Forget what may/may not have happened when you were 30.

That's all gone forever.

Do a refresher course on bjt behaviour and maybe you'll
understand, but parroting on will convince nobody that you know how bjts
actually work
why we use so much VOLTAGE NFB tom make all solid state amplifiers substanially
linear.





but I hope the whole group gets the benefit of what i am saying, and
is propelled to also experiment on a breadboard to understand these
things.

If youse don't look, youse won't know!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


But Trevor does not know anything about the input / output voltage
linearity of
bjts.

**That's because BJTs are CURRENT amplification devices. Your personal
attack is duly noted. Try to stay on topic. We're discussing devices, not
people.

I am on topic. Your lack of basic knowledge isn't an attack, I merely
am trying to direct wisdom towards your betterment.

**Then why do you ignore the basic facts about BJTs? Those facts being that
they are current amplification devices.

I AM NOT ignoring the known facts about linear current amplification in bjts.

And in some ways their current linearity is an inherent drawback because load
changes which change collector-emitter current is reflected by proportionally
the same
input base current changes, even where a shirtload of series VOLTAGE NFB is used
in the
emitter follower connection. The use of darlington pairs is thus a trick but
still leaves the
input base resistance too low for the high output resistance of the VAS.
yet more bjts have to be added into the cicuit, and soon you have
many devices, as any perusal of almost all SS amps will show.
Opamps have many devices.

NFB is used to overcome the poor linearity of all these devices.

If you want to tell me the devices arev LINEAR, period, then you have to also
explain
why so much NFB must be used to linerarize the circuits.

Now unless you can explain all this to the public concisely without parroting on
about
the current linearity, then you just don't know much NOW,
regardless of what you may have known when you were 30.



I am trying to get the groups understanding of the device behaviour to
become
deeper
and less superficial.

**Then it is VERY important to keep in mind that BJTs are current
amplification devices.

There's that parrot AGAIN.




Parrot statements does not constitute knowledge.

**Indeed. It is very important to ensure that people understand some
fundamental differences between BJTs and Triodes, however. Treating a BJTs
as if it is a Triode is just plain dumb.


He thinks the current linearity is the same as voltage linearity.

**That would be projection. Clearly, they're not the same, it's just that
it
does not matter. A good designer uses the appropriate device
appropriately.
USe a BJT in a circuit designed to use a Triode and the results will be
crap. USe a Triode in a circuit designed for a BJT and the results will
be
crap.

Your lack of understanding of the basics would prevent you ever designing
anything.

**That would be a personal attack and an avoidance of my point. Try again.

The world knows you have not attempted to design or build any amplifier since
1976.

I depend on my design and construct abilities to earn my living.

Should you accept what I am saying it may equip your mind to be more correctly
analytical about circuits you come across in your daily repair work.

IMHO its wrong for you to equate my education lessons as personal attacks.

I am just trying to point out more about bjts than you appear to know about.

To proove you understand bjts you would have to be able to correctly design
a basic preamp with a lone bjt and explain all the working voltage and current
signals
and NFB path/s.
I don't believe you could do this even though perhaps you could fix a circuit
with a fault
and fix it.

No offense meant.

Patrick Turner.



--
Trevor Wilson
www.rageaudio.com.au

--
Posted via a free Usenet account from http://www.teranews.com

[Prune]

Patrick Turner wrote in
:

If the circuit is PP, the only cancellations are in the even number
harmonics. And imperfect cancellations occur with N and P devices.

No, it's single ended but fully differential, so both + and - side of the
load are driven by identical stages, thus no use of complementary devices.
Actually the CCS does pull but below audio frequencies, it's mixed class
(see Pass' Aleph patent).

What schematic is attatched???

The damned XNews posted it as a separate message. I'm seeing it in the
list, but here's an alternative download for the PDF:
http://www.rapidsharing.com/download.php?id=37C87DBA

[Eeyore]

Prune wrote:

" wrote in news:1154111059.939212.316600
@s13g2000cwa.googlegroups.com:

Sounds a bit like NFB to me ;-)

Actuially, since you're feeding back just the error instead of the whole
signal, this is much more like Hawksford EC than typical NFB.

And then there's 'pre-distortion' in anti-phase that Nagra used for example. No
use of NFB there.

Graham

[Patrick Turner]

Andre Jute wrote:

I really don't know why you bother with Wilson. He is incorrigible. The
mindless man takes the joke about NFB in my sig seriously and builds
monstrous flame wars on it, and when I make jokes about germanium and
the founder of Fairchild, he takes that too as serious proof of
ignorance of transistors (or perhaps he doesn't know germanium is
obsolete or why Fairchild is important?). He simply cannot understand
that I am indifferent to transistors; it is not a state of mind he
permits. Trevor Wilson is another pork butcher insisting on his right
to set up a pig abattoir in a synagogue. He simply doesn't permit
anyone else to have an individual choice. You can't explain anything to
anyone with Wilson's mindset. He has no right to any more of my time or
my patience; as Al Marcy says, no one has a duty to explain. I'm out of
it.

Graham made more of an argument to try to convince me bjts were inherently
linear devices with a comparison between an MPSA42 with a shirtload of NFB
so it had the same gain as a 12AX7 with no loop NFB.
But he didn't have me change my mind.
Trevor isn't changing my mind either, and NOBODY else has presented an
argument in favour of the intrinsic voltage linearity because it doesn't exist.

They seem to prefer to be seen winning some argument in favour of silicon,
rather than discussing the appalling non linearity of bjts when used without NFB.

Trevor even proposed bjts didn't need NFB to be acceptable.

Now if the bjt is set up with a CCS collector load then the input resistance rises and
the input
impedance becomes more linear since the base emitter voltage change reduces to a tiny
voltage to cause a VOLTAGE change at the collector with CCS, ie, where no collector
current change is permitted.
Such is the huge bjt gain in a circuit about equal to Rc x gm, that the gain is as
high as a pentode with a CCS
lkoad, in the order of 1,000 to 5,000, and this gain is usually quite excessive, and
has to be tamed with NFB.
The voltage linearity without NFB under such conditions of no current change for
either pentode or bjt
is not too good, with several % of THD at output voltages equalling say 25% of the
supply voltages
normally required for best SE operation.

The use of current NFB in such CCS loaded circuits is fruitless because there is no
current change so
no current FB is possible.

So the only other viable local FB network around a single device is shunt FB,
and if the open loop gain of 2,000 of a bjt or pentode is reduced to say 20
in a typical 1 device preamp the amount of applied FB is 40dB, so that if there was
5% thd open loop, then with the FB the thd = 0.05%, and somewhat lower
than many triodes could achieve.
The linearity is a function of FB, not the intrinsic device linearity.

The effect on the effective anode resistance with such a loop of NFB
is to reduce the Ra by a factor = 1 / ( 1 + [µ x ß] ), so since the µ
of the pentode = gm x Ra, its not unusual for µ = 2,000.
So with a 6BX6 with ra = 500k, Ra effective with ß = 1/20 = 500k / ( 1 + [2,000 x
1/20] ) = 4.95k,
a respectably lower figure than when using the 6BX6 without NFB.

bjts are subject to the same reasoning except that engineers don't consider that they
have an "amplification factor, µ," like tubes do.
But they do in fact have Rc, dynamic collector resistance, usually way higher than any
usable load
connected and must have this reduced with shunt voltage NFB to effectively reduce this
resistance.

Somehow I feel Trevor is completely unaware of any of this basic reasoning about
devices.

Its a pity really, because he'd be a more effective repair person if he took the
trouble to understand the basics.

Whether the preamp stage with SE pentode or SE bjt with shunt FB sounds any good or
not is a moot point
and whether they sound better than a humble 6SN7 with NO loop NFB is another moot
point
and I leave people to answer that for themselves, I simply refuse to spoon feed the
crowd gathered
with free aesthetically based judgements; the truth about the sound is a personal
voyage I cannot make for
other people.


Patrick Turner.



Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
they will get off their collective fat arse and criminalize negative
feedback? It is clearly consumed only by undesirables.

Patrick Turner wrote:

Trevor Wilson wrote:

"Andre Jute" wrote in message
oups.com...

Trevor Wilson wrote:

"Andre Jute" wrote in message
oups.com...

Trevor Wilson wrote:

Jute continually refer to 2N3055
--
Trevor Wilson
www.rageaudio.com.au

No, I don't.

No such tube as the 2N3055 in my Compleat Mullard List of Really Good
Valves.

No such transistor as the 2N3055 in my Completely Up-to-date Germanium
Reference.

Just called my mate Bob Norris at Fairchild and he says you must be
smoking bad dope, Wilson.

**Then please provide a complete list of (power) transistors which you
have
direct experience with. Let's see how up to date your knowledge of
silicon
devices actually is. Please cite the curves which show how non-linear
these
devices are.

--
Trevor Wilson
www.rageaudio.com.au

1. Oh, dear, no sense of humour at Rage Audio. Typical silicon slime
characteristic.

2. I am not on trial for my knowledge of transistors. I don't do
transistors except to prove a point (my 675 amp) or as pseudo-choke
loads for more respectable devices.

**Then don't make idiotic comments about how linear Triodes are. If you
don't know how good modern transistors are, then you can't tell the world
that Triodes are better. Sure, A good Triode is better than a 2N3055, but it
can't match a modern transistor.

But you continue to make the idiotic comparison between triodes and bjts based
on entirely
false perceptions.

We already know the input / output VOLTAGE linearity of any appropriate triode
is better than a 2N3055.

We know that bjts have good current linearity.

Current linearity cannot be compared simply to voltage linearity.
Its like comparing oranges to asperagus

But Trevor does not know anything about the input / output voltage linearity of
bjts.

He thinks the current linearity is the same as voltage linearity.

In tubes, input / output current linearity cannot exist because there is no grid
current
unless the grid is run positively, and sometimes this is attempted, and the
voltage linearity
is not much disturbed, and the current linearity of tubes is quite poor.

In another 10 years maybe the Trevors of this world will learn to
be slower to shoot their mouth off about what they don't fully understand,
and then realize that understanding basics isn't the land of simplistic one
liners,
and that each and every statement about device operation is only quite valid
when a group
of operating conditions is clearly defined and kept in mind and correct context
when discussions occur.

Patrick Turner.






3. I do tubes. This is a tube conference. You're a guest here and you
stink like three day-old fish.

**My rights to exist here are precisely equivalent to yours. I have every
right to expose your lies/stupidity, whenever I see fit.

--
Trevor Wilson
www.rageaudio.com.au

--
Posted via a free Usenet account from http://www.teranews.com

[Patrick Turner]

Eeyore wrote:

Andre Jute wrote:

The dumbass (pun! pun!) Eeyore, usually known as Graham "Poopie"
Stevenson, wrote:

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Let's see what I actually wrote:

"The key word is "perceived". It is one of those real psychoacoustic
phenomena the engineers try to pretend cannot happen."

Aha, that "the engineers try to pretend cannot happen."

QED.

I just didn't put it strongly enough. I should have written, "that the
lesser engineers will call psychotic."

Andre Jute
Stop bleating. Please, please, please give me the Silence of the Lambs.

You're incapable of seeing the wood for the tress never mind making any
intelligent sonic judgement.

To your ears colouration = fidelity.

Graham

But myself and many others have heard large differences in different brands
of 6CG7
preamp triodes where the measured thd was less than
0.02% and utterly inaudible.

Nobody has explained this phenomena well enough to convince me artifacts
were the cause of the sound differences heard.

Relying solely on the measuring instruments was fruitless.

Patrick Turner.

[Patrick Turner]

Prune wrote:

Eeyore wrote in
:

There wasn't any attachment. In any case you're not supposed to post
binaries to non-binaries groups.

Xnews posted it as a separate message, in the thread paralelled with the
thext message you replied to.

If you don't see that, here's an alternative:
http://www.rapidsharing.com/download.php?id=37C87DBA
(it's a PDF file)

This site would not load in netscape and would not download in IE.

Please esablish your schematics at your website to allow us to easily peruse
it.

Patrick Turner.

[Eeyore]

Prune wrote:

Patrick Turner wrote in
:

If the circuit is PP, the only cancellations are in the even number
harmonics. And imperfect cancellations occur with N and P devices.

No, it's single ended but fully differential, so both + and - side of the
load are driven by identical stages, thus no use of complementary devices.
Actually the CCS does pull but below audio frequencies, it's mixed class
(see Pass' Aleph patent).

The final output stage is non-complementary which results in well known issues
rearding linearity mismatch. A poor choice IMHO.


What schematic is attatched???

The damned XNews posted it as a separate message.

Yeah - but you're not meant to post attachments to text based newsgroups.
They'll regularly get filtered out. Certainly not on any news server I can
access.


I'm seeing it in the
list, but here's an alternative download for the PDF:
http://www.rapidsharing.com/download.php?id=37C87DBA

I got it now thanks.

Graham

[Eeyore]

Patrick Turner wrote:

Eeyore wrote:

Andre Jute wrote:

The dumbass (pun! pun!) Eeyore, usually known as Graham "Poopie"
Stevenson, wrote:

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Let's see what I actually wrote:

"The key word is "perceived". It is one of those real psychoacoustic
phenomena the engineers try to pretend cannot happen."

Aha, that "the engineers try to pretend cannot happen."

QED.

I just didn't put it strongly enough. I should have written, "that the
lesser engineers will call psychotic."

Andre Jute
Stop bleating. Please, please, please give me the Silence of the Lambs.

You're incapable of seeing the wood for the tress never mind making any
intelligent sonic judgement.

To your ears colouration = fidelity.

Graham

But myself and many others have heard large differences in different brands
of 6CG7
preamp triodes where the measured thd was less than
0.02% and utterly inaudible.

Nobody has explained this phenomena well enough to convince me artifacts
were the cause of the sound differences heard.

Relying solely on the measuring instruments was fruitless.

Patrick Turner.

In which case I'll say you're the first person I've ever come across to present
such a case in an intelligent manner. Namely that you made some measurements and
can't find a correlation between them and the perceived results.

For my part I've always found good correlation betwen measurements and audible
effect but it goes beyond simple numbers. With distortion measurements for
example, it's critical IMHO to view the analyser output on a scope to get a feel
for the mechanism at work. X% of 2nd harmonic will be inaudible whereas X% of
classic crossover distortion will sound nasty.

I'd be interested in hearing more detail.

Graham

[Eeyore]

Patrick Turner wrote:

Prune wrote:

Eeyore wrote in
:

There wasn't any attachment. In any case you're not supposed to post
binaries to non-binaries groups.

Xnews posted it as a separate message, in the thread paralelled with the
thext message you replied to.

If you don't see that, here's an alternative:
http://www.rapidsharing.com/download.php?id=37C87DBA
(it's a PDF file)

This site would not load in netscape and would not download in IE.

Did you enter the 'security' code ? It foxed me for a bit - wasn't obvious.
Worked ok with Opera though.

Graham

[Prune]

Eeyore wrote in
:

The final output stage is non-complementary which results in well
known issues rearding linearity mismatch. A poor choice IMHO.

Yes, but it's opposed by an identical stage on the other side of the load.

[Prune]

Patrick Turner wrote in
:

Please esablish your schematics at your website to allow us to easily
peruse it.

The university does not like us doing this, but...
http://www.cs.ubc.ca/~trifonov/ax.pdf

[Prune]

flipper wrote in
:

It didn't work for me either so something might have happened to the
file after you got it.

I was using Firefox. I think the host I found has short time limits (it
was a non-registration required host, which is why I used it).

Try this instead:
http://www.cs.ubc.ca/~trifonov/ax.pdf

[Arny Krueger]

"flipper" wrote in message
...
On Sat, 29 Jul 2006 05:42:13 +0100, Eeyore
wrote:



Patrick Turner wrote:

Prune wrote:

Eeyore wrote in
:

There wasn't any attachment. In any case you're not supposed to post
binaries to non-binaries groups.

Xnews posted it as a separate message, in the thread paralelled with
the
thext message you replied to.

If you don't see that, here's an alternative:
http://www.rapidsharing.com/download.php?id=37C87DBA
(it's a PDF file)

This site would not load in netscape and would not download in IE.

Did you enter the 'security' code ? It foxed me for a bit - wasn't
obvious.
Worked ok with Opera though.

It didn't work for me either so something might have happened to the
file after you got it.

Worked fine if I downloaded it, and then opened it with Acrobat 7.0

[Arny Krueger]

"Sander deWaal" wrote in message
...
"Arny Krueger" said:


Exactly that is the problem - no H2, no euphonics ;-)


If THD is below 1%, then so is H2, and H2 is inaudible below 1% in
blind
testing.


Not true.

It is pretty easy to set up a DBT in which 2nd order nonlinear
distortion
that creates 1% distortion can be easily and reliably heard.

This extends down to about 0.1 %. Therefore all of the equipment in a
record/reproduce system taken together needs to have all forms of
nonlinear
distortion at 0.05% or less.

The individual components in a home audio system need to be even better
than
this, because there are 2-3 or more active components in a reproduction
system.


And the nonlinear distortion of your speakers is......?


..what people manage to hear past in order to pass these DBTs.


Thanks Arny for admitting Arny the clue you bought on E-bay was
actually a Tektronix plug-in for a mainframe you don't have, LOL! ;-)

Please post again when you run out of whatever mind-altering drug you're
currently on, Sander.

[Sander deWaal]

"Arny Krueger" said:


"Sander deWaal" wrote in message
.. .
"Arny Krueger" said:


Exactly that is the problem - no H2, no euphonics ;-)


If THD is below 1%, then so is H2, and H2 is inaudible below 1% in
blind
testing.


Not true.

It is pretty easy to set up a DBT in which 2nd order nonlinear
distortion
that creates 1% distortion can be easily and reliably heard.

This extends down to about 0.1 %. Therefore all of the equipment in a
record/reproduce system taken together needs to have all forms of
nonlinear
distortion at 0.05% or less.

The individual components in a home audio system need to be even better
than
this, because there are 2-3 or more active components in a reproduction
system.


And the nonlinear distortion of your speakers is......?


..what people manage to hear past in order to pass these DBTs.


Thanks Arny for admitting Arny the clue you bought on E-bay was
actually a Tektronix plug-in for a mainframe you don't have, LOL! ;-)


Please post again when you run out of whatever mind-altering drug you're
currently on, Sander.


You should try it one day, dude.

BTW measured your speaker's THD and IMD yet? ;-)

--
"All amps sound alike, but some sound more alike than others".

[Trevor Wilson]

"Patrick Turner" wrote in message
...


Eeyore wrote:

Andre Jute wrote:

The dumbass (pun! pun!) Eeyore, usually known as Graham "Poopie"
Stevenson, wrote:

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Let's see what I actually wrote:

"The key word is "perceived". It is one of those real psychoacoustic
phenomena the engineers try to pretend cannot happen."

Aha, that "the engineers try to pretend cannot happen."

QED.

I just didn't put it strongly enough. I should have written, "that the
lesser engineers will call psychotic."

Andre Jute
Stop bleating. Please, please, please give me the Silence of the Lambs.

You're incapable of seeing the wood for the tress never mind making any
intelligent sonic judgement.

To your ears colouration = fidelity.

Graham

But myself and many others have heard large differences in different
brands
of 6CG7
preamp triodes where the measured thd was less than
0.02% and utterly inaudible.

Nobody has explained this phenomena well enough to convince me artifacts
were the cause of the sound differences heard.

**Then you were not making enough measurements. Measurements can reveal the
differences between amplifiers and components within those amplifiers.
Here's a few POSSIBILITIES:

* Differences in microphonics.
* Differences in gain.
* Differrences in THD/IMD at different frequencies.
* Differences in THD/IMD at different levels/frequencies.
* Et al.

There are a huge number of variables in any device which provides gain in an
amplification stage. Considering the topology was probably a low Global NFB
one, any variation in any of the parameters may be the explanation for the
differences heard. Whatever those differences are, they are most certainly
measurable, PROVIDED you are measuring the correct thing.


Relying solely on the measuring instruments was fruitless.

**Assuming you measured everything.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Patrick Turner]

Eeyore wrote:

Patrick Turner wrote:

Eeyore wrote:

Andre Jute wrote:

The dumbass (pun! pun!) Eeyore, usually known as Graham "Poopie"
Stevenson, wrote:

Andre Jute wrote:

The key word is "perceived". It is one of those real psychoacoustic
phenomena

I think you mean psychotic actually.

Let's see what I actually wrote:

"The key word is "perceived". It is one of those real psychoacoustic
phenomena the engineers try to pretend cannot happen."

Aha, that "the engineers try to pretend cannot happen."

QED.

I just didn't put it strongly enough. I should have written, "that the
lesser engineers will call psychotic."

Andre Jute
Stop bleating. Please, please, please give me the Silence of the Lambs.

You're incapable of seeing the wood for the tress never mind making any
intelligent sonic judgement.

To your ears colouration = fidelity.

Graham

But myself and many others have heard large differences in different brands
of 6CG7
preamp triodes where the measured thd was less than
0.02% and utterly inaudible.

Nobody has explained this phenomena well enough to convince me artifacts
were the cause of the sound differences heard.

Relying solely on the measuring instruments was fruitless.

Patrick Turner.

In which case I'll say you're the first person I've ever come across to present
such a case in an intelligent manner. Namely that you made some measurements and
can't find a correlation between them and the perceived results.

For my part I've always found good correlation betwen measurements and audible
effect but it goes beyond simple numbers. With distortion measurements for
example, it's critical IMHO to view the analyser output on a scope to get a feel
for the mechanism at work. X% of 2nd harmonic will be inaudible whereas X% of
classic crossover distortion will sound nasty.

I'd be interested in hearing more detail.


There were 4 audio enthusiasts present, myself and 3 other guys.
The preamp used to test differences in audibility of different "tube timbre"
had a DACT source swithch, DACT input gain attenuator followed by a common cathode
gain triode
with direct cathode follower output of 600 ohms Rout, then
13EI power amps with loop NFB and Vienna Accoustic Motzart floor standing speakers.
Power amp thd was estimated at less than 0.05% at all times

The input signal from CD source was reduced by about 30dB before being amplified
about 12 times by the gain triode which had an unbypassed Rk, all of which is
typical
simple SET preamp topology.

The power amps needed 0.8Vrms for clipping which was never reached during tests.
The preamp output signal levels used were never more than about 0.1Vrms average.

The measured preamp had about 0.3% thd at about 20Vrms, mainly 2H,
so that with 0.1Vrms, thd = approx 0.0085%, a typical result for a 6SN7.
The graphs I carefully measured show this.
The preamp was altered to µ follower topology and the thd fell 6dB at 10Vrms to
about 0.7% and at 0.1vrms thd 0.004%.

When ppl tell me how terribly awful SET preamps are I just laugh;
they just don't know what they are talking about.

The worst preamp 6CG7 we tried for the day were new russian 6CG7 made in about 2002,
harsh & rough,
then the order of preference was Mullard, polite with recessed bass and treble, but
great with female vocals,
then Oz made 6CG7, NOS, very close to the best we tested which was the Seimans 6CG7.

There is a lot of BS about tubes, but to know your own truth you must try different
tubes.
In preamps without global NFB such as the preamp above the sonics change
with tube choices, even with miniscule thd regardless of the tube choices.
Frankly, probably only the pickiest fussy audiophiles are able to tell much
difference between
brands of triodes of the same type, all of which can usually be considered "good
wines"
to begin with and its only by changeing tubes the differences become apparent.

Ppl used to make similar convoluted assessments about subjective sonics with
varieties of japanese transistors 25 years ago,
but all those circuits had huge amounts of loop NFB to get the thd low, and hardle
anyone did AB tests
with triodes in the room.



Patrick Turner.







Graham