[[email protected]]

"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes

[[email protected]]

On May 28, 11:03*am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. I just want to
hear what was recorded. The fatal flaw in your comment is
"generate". Why should the amp be generating content? A solid state
amp can pass any original harmonic content within human range that is
on the source just as well as a tube amp.

[Dave]

wrote in message
...
On May 28, 11:03 am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. I just want to
hear what was recorded. The fatal flaw in your comment is
"generate". Why should the amp be generating content? A solid state
amp can pass any original harmonic content within human range that is
on the source just as well as a tube amp.

Lots of folks like the "warm" tube sound. It's a personal preference, akin
to one's choice of speakers. Me, I like both, and have two systems, one
with a tubed amp and one with a solid state.

I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise. Not that that's a reason to
choose one over the other...

[[email protected]]

On May 28, 11:42*am, "Dave" wrote:
wrote in message

...
On May 28, 11:03 am, wrote:

"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. *I just want to
hear what was recorded. *The fatal flaw in your comment is
"generate". *Why should the amp be generating content? *A solid state
amp can pass any original harmonic content within human range that is
on the source just as well as a tube amp.

Lots of folks like the "warm" tube sound. *It's a personal preference, akin
to one's choice of speakers. *Me, I like both, and have two systems, one
with a tubed amp and one with a solid state.

I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise. *Not that that's a reason to
choose one over the other...

Warm? Can you quantify it? I think not.

The tube overdrive distortion is intentionally used sometimes by
electric guitar musicians. Someone decided to expand that and make it
a reason to prefer tube amps over solid state. If you're playing an
electric guitar then sure. But if you're playing recorded music then
no, do not overdrive your amp.

[Ian Thompson-Bell]

wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone
that generate pleasing 2nd harmonic distortion. Pentodes generate odd
harmonics just as much as transistors do.

Second the amount of distortion is level dependent. The output stages of
an amp create by far the most distortion. Any push pull amp output stage
will, by definition cancel most of the even order harmonics and leave
many nasty odd harmonics in the output - no better in that respect than
a transistor amp.

So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Cheers

Ian

[Peter Wieck]

On May 28, 11:03*am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

Um, this is a troll. And firmly rooted in received wisdom and blind
faith.

As such, no opinions will be made or changed by it, it serves no
useful purpose, and comment upon it merely gives the Original Poster
the attention he/she wants anyway.

Those who prefer tubes will continue to prefer them. Those who enjoy
tubes as another aspect of the Audio Hobby will continue to do so...
and so forth.

Peter Wieck
Melrose Park, PA

[Arny Krueger]

wrote in message


"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior when it comes to
passing harmonic content. They are just too nonlinear and just too limited
in terms of power bandwidth to compare with more modern alternatives.

As far as the generation of harmonic content goes, it is unclear why
maximizing harmonic content would even be desirable in a component of a high
fidelity system. Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would be from the digital
domain.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.

It is a myth that triodes generate only even harmonics. In fact, tubes have
basically exponential response, which leads to the generation of a wide
variety of orders of distortion, both odd and even.

[Tzortzakakis Dimitrios[_2_]]

? ?????? ??? ??????
...
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

No idea, never heard one. I find though, vacuum tube circuits fascinating.
For my thesis, I constructed an AM transmitter with an 6C4 for oscillator,
and a 807 for final stage, class C of course, complete with antenna,
resonating circuit, modulation transformer and 50 W solid state amplifier.



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

[RapidRonnie]

On May 28, 2:08 pm, "Arny Krueger" wrote:
wrote in message



"In a word: YES...
"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior when it comes to
passing harmonic content. They are just too nonlinear and just too limited
in terms of power bandwidth to compare with more modern alternatives.

As far as the generation of harmonic content goes, it is unclear why
maximizing harmonic content would even be desirable in a component of a high
fidelity system. Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would be from the digital
domain.

Properly designed tube amplifiers have entirely satisfactory bandpass
and distortion characteristics. Passing frequencies above 35-50 kHz is
very undesireable in an audio amplifier. Ideally a shallow taper from
about 25 kHz and a drop at 50 or so is desireable.

Many solid state audio amplifiers work well for RF in the 100-300 kHz
range. That is not a feature, it's a bug. The output transformer of a
tube amplifier beneficially throttles this extreme HF response.

[RapidRonnie]

3. Compared to solid state, tube amps are a pain in the ass. They hum, hiss,
burble, and motorboat, either out of the box, or many years before a SS amp
would be vulnerable to aging components.


Nonsense. Solid state amps fail hard and take speakers with them all
the time. Tube ones rarely do. They are easier for the hobbyist to
troubleshoot.

[Arny Krueger]

"RapidRonnie" wrote in message

3. Compared to solid state, tube amps are a pain in the
ass. They hum, hiss, burble, and motorboat, either out
of the box, or many years before a SS amp would be
vulnerable to aging components.

Nonsense. Solid state amps fail hard and take speakers
with them all the time.

And tubed amps never ever fried speakers? Surely you jest!

Whenever you start talking about accidents, you have to consider the number
of tubed amps versus the number of SS amps. At this point, tubed amps
probably make up less than 0.1% of all amplifiers in use.

Tube ones rarely do.

One reason - tubed amps are themselves quite rare.

They are easier for the hobbyist to troubleshoot.

Those of us who lived through the bad old days of tubes, know that SS amps
are tremendously more reliable.

[Arny Krueger]

"RapidRonnie" wrote in message

On May 28, 2:08 pm, "Arny Krueger"
wrote:
wrote in message



"In a word: YES...
"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior
when it comes to passing harmonic content. They are
just too nonlinear and just too limited in terms of
power bandwidth to compare with more modern
alternatives.

As far as the generation of harmonic content goes, it is
unclear why maximizing harmonic content would even be
desirable in a component of a high fidelity system.
Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would
be from the digital domain.

Properly designed tube amplifiers have entirely
satisfactory bandpass and distortion characteristics.

Well, if you say that for a far higher price and considerably greater
inconvenience, it is possible to have a tubed amp with good performance, I'd
have to agree.


Passing frequencies above 35-50 kHz is very undesireable
in an audio amplifier. Ideally a shallow taper from about
25 kHz and a drop at 50 or so is desirable.

If you include the effects of real-world speaker loads, most tubed amps have
audible issues inside the 20-20 kHz range because of their far higher source
impedance.

Good thing you have nothing to say about the low bad performance of tubed
amps, because all but the really expensive and heavy ones do rather more
poorly in the bass.


Many solid state audio amplifiers work well for RF in the
100-300 kHz range.

That's not typical. Everybody knows that ultrasonic response is an open door
for problems with EMI, etc. Most SS amps have artificially sacrificed high
frequency response to enhance their usability.

That is not a feature, it's a bug. The
output transformer of a tube amplifier beneficially throttles this extreme
HF response.

Throttling the HF response of a SS amp only takes one or two penny-cost
capacitors.

But I will give the majority of tubed amps a nod of sorts for their inferior
power bandwidth below 30 Hz.

[RapidRonnie]

3. Compared to solid state, tube amps are a pain in the
ass. They hum, hiss, burble, and motorboat, either out
of the box, or many years before a SS amp would be
vulnerable to aging components.
Nonsense. Solid state amps fail hard and take speakers
with them all the time.

And tubed amps never ever fried speakers? Surely you jest!

It's happened but not to me.


Whenever you start talking about accidents, you have to consider the number
of tubed amps versus the number of SS amps. At this point, tubed amps
probably make up less than 0.1% of all amplifiers in use.

If even that many, but when you consider the percent overall as
restricted to serious hobbyists it's 25% or so.


Tube ones rarely do.

One reason - tubed amps are themselves quite rare.

No, among _high end hobbyists_ they are fairly common.


They are easier for the hobbyist to troubleshoot.

Those of us who lived through the bad old days of tubes, know that SS amps
are tremendously more reliable.

Those of us living in the good new days of tubes have no trouble
keeping them running with some good basic technicianship and the
appropriate tools. We don't need curvetracers, constant current bias
supplies or milling machines to keep them going.

[RapidRonnie]

If you include the effects of real-world speaker loads, most tubed amps have
audible issues inside the 20-20 kHz range because of their far higher source
impedance.

Good thing you have nothing to say about the low bad performance of tubed
amps, because all but the really expensive and heavy ones do rather more
poorly in the bass.

All tube amps are expensive and heavy these days. No one is
advocating them for subwoofer drivers.

Any good push pull 6L6 or 6550 power amp will drive a classic
Klipsch, Altec or JBL setup to higher bass SPLs than any normal person
can tolerate. Headbangers wanting more should move out of town so as
not to disturb the rest of us.

[Trevor Wilson[_2_]]

wrote in message
...
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

**Nonsense. Valves are inherently high frequency devices. As such, they are
easily capable of passing or generating higher order harmonics. There are
more problems with your nonsensical statement. These include:

* The TOPOLOGY can be far more important than the devices used, WRT high
order harmonic generation.
* The use of triodes or pentodes can affect sound quality most profoundly.
* The presence of an output transformer will affect high order harmonic
generation to a greater degree than the type of output device used.

--
Trevor Wilson
www.rageaudio.com.au

[Arny Krueger]

"RapidRonnie" wrote in message


Those of us who lived through the bad old days of tubes,
know that SS amps are tremendously more reliable.

Those of us living in the good new days of tubes have no
trouble keeping them running with some good basic
technicianship and the appropriate tools.

Plan B - use SS amps which generally just run and run and run.

We don't need curvetracers,

Never did, for SS.

constant current bias supplies

Don't make sense for tubes since their properties are a moving target.

or milling machines

?????????????/

to keep them going.

If you call what the typical tubed amp does, "going".

[jamesgangnc]

"RapidRonnie" wrote in message
...


If you include the effects of real-world speaker loads, most tubed amps
have
audible issues inside the 20-20 kHz range because of their far higher
source
impedance.

Good thing you have nothing to say about the low bad performance of tubed
amps, because all but the really expensive and heavy ones do rather more
poorly in the bass.

All tube amps are expensive and heavy these days. No one is
advocating them for subwoofer drivers.

Any good push pull 6L6 or 6550 power amp will drive a classic
Klipsch, Altec or JBL setup to higher bass SPLs than any normal person
can tolerate. Headbangers wanting more should move out of town so as
not to disturb the rest of us.

Tubes are inherently bad devices to drive a low impedance load where as
solid state is perfectly happy being coupled directly to a speaker. You
can't make a tube current amp and that's what you need for audio.

[Ian Thompson-Bell]

flipper wrote:
On Wed, 28 May 2008 17:34:05 +0100, Ian Thompson-Bell
wrote:

wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes

There is a lot missing from this article.

Yes, as well as full of 'opinion'. There's not a single measurement in
it.

First, it is triodes alone
that generate pleasing 2nd harmonic distortion.

No, you're confusing SE with PP.


No, I was being inaccurate! I should have said triodes generate a larger
proportion of second harmonic compared to higher ones than either
pentodes of BJTs.

Pentodes generate odd
harmonics just as much as transistors do.

No and it's misleading to speak of simply 'odd' harmonics. It's the
higher order harmonics that are harsh and then there's the issue of
the harmonic mix.

Hmm, the ratio of 3rd (and higher odd harmonics) to 2nd harmonic
distortion in pentodes is greater than in triodes because of the
different transfer function.


All of which smacks a bit of voo-doo because, according to
measurements, they're all below 'audible' and so, in theory, should be
of no consequence. But then, and again according to measurements, THD
that's 'inaudible' (or at least unoffensive) in a tube amp offends
like nails on a blackboard in SS amps so an SS amp *must* have lower
THD figures to be tolerable.


The danger here of course is that measuring THD alone is not sufficient.

Second the amount of distortion is level dependent. The output stages of
an amp create by far the most distortion. Any push pull amp output stage
will, by definition cancel most of the even order harmonics

Which includes triodes.

Indeed.


and leave
many nasty odd harmonics in the output - no better in that respect than
a transistor amp.

No.

Which bit is not correct the whole or just the latter part?


So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Judging from the rest you apparently mean "even harmonics" but what
does "mainly" mean?

Yes, mixing my odds and evens again.


Cheers

Ian

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes

There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.

It is a myth that triodes generate only even harmonics. In fact, tubes have
basically exponential response, which leads to the generation of a wide
variety of orders of distortion, both odd and even.



No, pentodes have an exponential transfer function like BJTs do, but
triodes have a simpler ^3/2 transfer function which produces a different
harmonic content.

Cheers

Ian

[Trevor Wilson[_2_]]

"RapidRonnie" wrote in message
...


3. Compared to solid state, tube amps are a pain in the ass. They hum,
hiss,
burble, and motorboat, either out of the box, or many years before a SS
amp
would be vulnerable to aging components.


Nonsense. Solid state amps fail hard.

**Some do, but if you install a distortion producing, phase shifting output
transformer between output devices and load (like most valve amps) then the
problem is solved.

and take speakers with them all
the time.

**Incorrect. Many solid state amps employ sophisticated protection systems
to prevent this from happening. Then, of course, one could employ an output
transformer.

Tube ones rarely do.

**Largely because they have a distortion producing, phase shifting output
transformer, between load and output devices.

They are easier for the hobbyist to
troubleshoot.

**That much may well be true, depending on the topology. Fortunately for
hobbyists, solid state amps tend to be vastly more reliable.

--
Trevor Wilson
www.rageaudio.com.au

[Trevor Wilson[_2_]]

"Ian Thompson-Bell" wrote in message
...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone that
generate pleasing 2nd harmonic distortion. Pentodes generate odd harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why this myth continues to
be perpetrated is a complete mystery. The TOPOLOGY dictates what type of
harmonics are generated, not the devices. Push pull eliminates even order
distortion products. Valve or solid state.


Second the amount of distortion is level dependent. The output stages of
an amp create by far the most distortion. Any push pull amp output stage
will, by definition cancel most of the even order harmonics and leave many
nasty odd harmonics in the output - no better in that respect than a
transistor amp.

**Nonsense.


So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

**Nonsense. Where you do you get this nonsense from?


--
Trevor Wilson
www.rageaudio.com.au

[Norman M. Schwartz]

RapidRonnie wrote:
3. Compared to solid state, tube amps are a pain in the ass. They
hum, hiss, burble, and motorboat, either out of the box, or many
years before a SS amp would be vulnerable to aging components.


Nonsense. Solid state amps fail hard and take speakers with them all
the time. Tube ones rarely do. They are easier for the hobbyist to
troubleshoot.

Good tubes, their matched pairs, etc. are expensive and not easy to find.
Useful individual tube life is a variable. Many listeners are constantly
concerned, listening for signs of their wear, buy and stock replacement
tubes, spend their listening time listening to the tubes, comparing the
sound of various tubes, their manufacturer, and then very model of a "6550"
etc, etc.) rather than the music. Most often tube amps generate more heat,
than their SS counterparts, and _may_ require the use of noise producing
fans and extensive ventilation. One shouldn't choose to stack other
equipment above them, and eventually self-destruct because of the heat they
generate. Caged or uncaged their heat is a threat to pets and young
children.In the end analysis their characteristic sound has to be a mix of
the nature of the tubes employed and the amp itself.

[Trevor Wilson[_2_]]

"RapidRonnie" wrote in message
...
On May 28, 2:08 pm, "Arny Krueger" wrote:
wrote in message



"In a word: YES...
"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior when it comes to
passing harmonic content. They are just too nonlinear and just too
limited
in terms of power bandwidth to compare with more modern alternatives.

As far as the generation of harmonic content goes, it is unclear why
maximizing harmonic content would even be desirable in a component of a
high
fidelity system. Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would be from the
digital
domain.

Properly designed tube amplifiers have entirely satisfactory bandpass
and distortion characteristics. Passing frequencies above 35-50 kHz is
very undesireable in an audio amplifier. Ideally a shallow taper from
about 25 kHz and a drop at 50 or so is desireable.

**Bull****. Such a poor frequency response, will lead to a severely and
audibly compromised phase response. The human ear is very sensitive to phase
problems. A linear frequency response, which leads to a close to 0 degree
phase shift at 20kHz is desirable.


Many solid state audio amplifiers work well for RF in the 100-300 kHz
range. That is not a feature, it's a bug. The output transformer of a
tube amplifier beneficially throttles this extreme HF response.

**Bull****. The output transformer damages the frequency response of valve
amps. Valves are inherently high frequency devices.


--
Trevor Wilson
www.rageaudio.com.au

[Trevor Wilson[_2_]]

"flipper" wrote in message
...
On Thu, 29 May 2008 09:01:52 +1000, "Trevor Wilson"
wrote:



"Ian Thompson-Bell" wrote in message
...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone
that
generate pleasing 2nd harmonic distortion. Pentodes generate odd
harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why this myth continues
to
be perpetrated is a complete mystery. The TOPOLOGY dictates what type of
harmonics are generated, not the devices.

Well, you're half right. They both dictate the harmonics.

**I am 100% correct. Topology is the factor. Not the devices. Of course,
various devices DO contribute different distortion amounts. For instance:

* At low bias currents, pentodes add large amounts of distortion.
* At low bias current, triodes add smaller amounts of distortion.
* At low bias currents, MOSFETs add very large amounts of distortion.
* At low bias currents, BJTs add smaller amounts of distortion.


Push pull eliminates even order
distortion products. Valve or solid state.

But does nothing for the odd orders, which are dictated by the
devices.

**Sure. ALL amplifiying devices add odd order distortion. At moderate bias
currents, the approximate order is (from best to worst):

BJTs
Triodes
Pentodes
MOSFETs

At high bias currents, the order shifts somewhat to:

BJTs
MOSFETs
Triodes
Pentodes

It is the TOPOLOGY which dominates the issue of distortion production,
however. Depending on the amount of feedback employed, the devices used
makes little difference.

--
Trevor Wilson
www.rageaudio.com.au

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes

There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.

It is a myth that triodes generate only even harmonics.
In fact, tubes have basically exponential response,
which leads to the generation of a wide variety of
orders of distortion, both odd and even.

No, pentodes have an exponential transfer function like
BJTs do, but triodes have a simpler ^3/2 transfer
function which produces a different harmonic content.

In my book, what you call ^3/2 transfer function is just another flavor of
exponential.

A ^3/2 transfer function can be read as the square root of cubed, which is
nothing like pure even order or pure second order.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something symmetrical, like
push-pull.

[Mr.T]

"Dave" wrote in message
news:z3f%j.232$i74.144@edtnps91...
I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise.

And of course a tube amp is likely to be overdriven, generally being of
relatively low power output, whereas a solid state amp should never need to
be overdriven in the first place, with large power outputs available at
relatively low cost. (or extremely low cost when compared to most tube
amps!)

MrT.

[Trevor Wilson[_2_]]

"flipper" wrote in message
...
On Thu, 29 May 2008 09:56:14 +1000, "Trevor Wilson"
wrote:



"flipper" wrote in message
. ..
On Thu, 29 May 2008 09:01:52 +1000, "Trevor Wilson"
wrote:



"Ian Thompson-Bell" wrote in message
...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can
pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone
that
generate pleasing 2nd harmonic distortion. Pentodes generate odd
harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why this myth
continues
to
be perpetrated is a complete mystery. The TOPOLOGY dictates what type
of
harmonics are generated, not the devices.

Well, you're half right. They both dictate the harmonics.

**I am 100% correct.

No, you're not.

Topology is the factor.

It's one factor.

**It is, by far, the major factor. It swamps any influences by the output
devices. Take away global NFB, for instance, and differences between devices
is more readily apparent.


Not the devices.

B.S.

**Keep dissagreeing all you wish. You'll still be wrong.


Of course,
various devices DO contribute different distortion amounts.

And different harmonic distributions as well.

**All of which is swamped by topology differences.



For instance:

* At low bias currents, pentodes add large amounts of distortion.
* At low bias current, triodes add smaller amounts of distortion.
* At low bias currents, MOSFETs add very large amounts of distortion.
* At low bias currents, BJTs add smaller amounts of distortion.


Push pull eliminates even order
distortion products. Valve or solid state.

But does nothing for the odd orders, which are dictated by the
devices.

**Sure. ALL amplifiying devices add odd order distortion.

Yes, but with different distributions.

**All of which is swamped by different topologies.


At moderate bias
currents, the approximate order is (from best to worst):

BJTs
Triodes
Pentodes
MOSFETs

At high bias currents, the order shifts somewhat to:

BJTs
MOSFETs
Triodes
Pentodes

Except for BJTs being the worst of the lot under all conditions that's
not too terribly screwed up.

**Wrong. Modern BJTs are, by far, the most linear output devices available.
Look at the Hfe vs. Ic curve of this device:

http://www.datasheetcatalog.org/data...shiba/3228.pdf

A VERY linear (low distortion) device over a very wide range of currents.
It's PNP complement is similarly low distortion.



It is the TOPOLOGY which dominates the issue of distortion production,
however.

Wrong.

**Don't be silly. Compare SE to PP. Compare zero global NFB to high global
NFB topologies.


Depending on the amount of feedback employed, the devices used
makes little difference.

Also wrong.

**Here's where I get to say: PROVE IT.


--
Trevor Wilson
www.rageaudio.com.au

[jakdedert]

Soundhaspriority wrote:
snip
It seems possible to avoid that dilemma. I have never experienced audible
distortion due to overdriving a SS amplifier, because I do not overdrive
them.

Boy, that one really sets my bull**** detector off! You've NEVER heard
distortion...in your life? Never heard an overdriven car stereo, or AM
radio? Never wanted to get 'just a little more' out of a system and
went a little too far before you backed off? Never been surprised by
unexpectedly loud passage in a piece, which drove your system into
clipping? Ever?

Right....

jak
Bob Morein
(310) 237-6511

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes
There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.
It is a myth that triodes generate only even harmonics.
In fact, tubes have basically exponential response,
which leads to the generation of a wide variety of
orders of distortion, both odd and even.

No, pentodes have an exponential transfer function like
BJTs do, but triodes have a simpler ^3/2 transfer
function which produces a different harmonic content.

In my book, what you call ^3/2 transfer function is just another flavor of
exponential.


I sujggest you get a better book.

A ^3/2 transfer function can be read as the square root of cubed, which is
nothing like pure even order or pure second order.


A simple expansion shows that the even order terms dominate. See any
book on tubes for details.

Cheers

Ian

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something symmetrical, like
push-pull.



NO, PP CANCELS odd harmonics.

Cheers

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something symmetrical, like
push-pull.



Sorry, I meant even harmonics and my prior reply to this post was BS.

CHeers

Ian

[Arny Krueger]

"jakdedert" wrote in message
news
Soundhaspriority wrote:
snip
It seems possible to avoid that dilemma. I have never
experienced audible distortion due to overdriving a SS
amplifier, because I do not overdrive them.

Boy, that one really sets my bull**** detector off! You've NEVER heard
distortion...in your life? Never
heard an overdriven car stereo, or AM radio? Never
wanted to get 'just a little more' out of a system and
went a little too far before you backed off? Never been
surprised by unexpectedly loud passage in a piece, which
drove your system into clipping? Ever?

That's an excluded middle argument.

Of course we've all heard overdriven amps. I sure have, and for the first 20
or so years of my life, they all had vacuum tubes.

A good quality tubed amp with loop feedback makes nice looking square waves
when overdriven, pretty much like a good SS amp does today.

The relevant point is that good clean SS power is relatively inexpensive and
reliable. High power from a SS amp is way under $0.50 per watt. In the days
of tubes, $1.00 per watt was an unachievable goal for quality power. Today,
that same tubed amp costs 6-10 times or more as much.

In order to have 300 wpc from a tubed amp, you need to have a lot of output
tubes which increases the cost of service pretty dramatically, because high
performance tubed amps need fresh tubes to keep their performance high. Then
you need a very expensive, large and heavy output transformer. Finally, the
power transformer needs to be larger because tubes are less efficient.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that
the device can pass or generate..."

Continued: http://easyurl.net/TubesTubes
There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as
much as transistors do.

It is a myth that triodes generate only even harmonics.
In fact, tubes have basically exponential response,
which leads to the generation of a wide variety of
orders of distortion, both odd and even.

No, pentodes have an exponential transfer function like
BJTs do, but triodes have a simpler ^3/2 transfer
function which produces a different harmonic content.

In my book, what you call ^3/2 transfer function is
just another flavor of exponential.

I sujggest you get a better book.

Sue me for having a better general knowlege of math.

I also suggest you stop confusing "less odd harmonic" with "no odd
harmonic".

A ^3/2 transfer function can be read as the square root
of cubed, which is nothing like pure even order or pure
second order.

A simple expansion shows that the even order terms
dominate. See any book on tubes for details.

The same book says that there are significant odd-order terms. Maybe not
quite as big, but still there and audibly significant.

Furthermore, running tubes in either a balanced configuration (often done in
line level tubes amps used for audio production) or push-pull configuration
(done in any decent power amp) cancels out the even ordered terms very
nicely. Thus, the remaining odd-order terms are far more significant.

Bottom line is that most real-world tubed amps put out plenty of odd-order
distortion, no matter what kind of word games that the tubed amp bigots try
to play.

[Arny Krueger]

"flipper" wrote in message

On Thu, 29 May 2008 09:56:14 +1000, "Trevor Wilson"
wrote:



"flipper" wrote in message
...
On Thu, 29 May 2008 09:01:52 +1000, "Trevor Wilson"
wrote:



"Ian Thompson-Bell" wrote in
message ...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that
the device can pass or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it
is triodes alone that
generate pleasing 2nd harmonic distortion. Pentodes
generate odd harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why
this myth continues to
be perpetrated is a complete mystery. The TOPOLOGY
dictates what type of harmonics are generated, not the
devices.

Well, you're half right. They both dictate the
harmonics.

**I am 100% correct.

No, you're not.

Topology is the factor.

It's one factor.

Not the devices.

B.S.

Of course,
various devices DO contribute different distortion
amounts.

And different harmonic distributions as well.

For instance:

* At low bias currents, pentodes add large amounts of
distortion.
* At low bias current, triodes add smaller amounts of
distortion.
* At low bias currents, MOSFETs add very large amounts
of distortion.
* At low bias currents, BJTs add smaller amounts of
distortion.


Push pull eliminates even order
distortion products. Valve or solid state.

But does nothing for the odd orders, which are dictated
by the devices.

**Sure. ALL amplifying devices add odd order distortion.

Yes, but with different distributions.

So what?

With SS amps we don't have as much problem with phase shift inside the loop
hindering the proper use of loop feedback. It is far more economically
feasible to have large open loop gain. Thus despite all the intuitively
attractive but completely wrong-headed hand-waving arguments against loop
feedback, SS amps are able to use more of it. The net result is that SS amps
are far more linear, particularly at the ends of the audible range.

We've already had one tubie admit that even the best tubed amps make very
suboptimal subwoofer amps. Less-expensive tubes amps such as the classic
Dyna 70 and the amplifier sections of the better tubed receivers start
crapping out below 100 Hz which is well into the normal audible range for
even bookshelf speakers.


At moderate bias
currents, the approximate order is (from best to worst):

BJTs
Triodes
Pentodes
MOSFETs

At high bias currents, the order shifts somewhat to:

BJTs
MOSFETs
Triodes
Pentodes

Except for BJTs being the worst of the lot under all
conditions that's not too terribly screwed up.

It doesn't matter. Device linearity doesn't matter nearly as much as the
final performance of the finished product. One of the strong advantages of
SS is the ability to economically cascade stages to get higher open-loop
gain with low enough phase shift to provide superior stability margins at
all relevant frequencies.

It is the TOPOLOGY which dominates the issue of
distortion production, however.

Wrong.

Just saying it without supporting evidence is just meaningless posturing.

Depending on the amount of feedback employed, the
devices used
makes little difference.

Also wrong.

Just saying it without supporting evidence is just meaningless posturing.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something
symmetrical, like push-pull.


NO, PP CANCELS odd harmonics.

A totally false statement that any second-year engineering student would
recognize as being false.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something
symmetrical, like push-pull.



Sorry, I meant even harmonics and my prior reply to this
post was BS.

Well, now having corrected yourself - deal with the issue that I raised.

[Peter Wieck]

On May 28, 11:48*pm, jakdedert wrote:

Boy, that one really sets my bull**** detector off! *

Um... get with the program. This thread is a cross-posted unabashed
troll covering well-plowed, entirely exhausted ground without even a
scintilla of revealing, even useful information.

Is it any surprise that it brings out the crap-peddlers and bull****
artists? Those preaching revealed religion and those espousing their
closely-held-beliefs? The pretenders and the poseurs?

I keep a Citation 16 and a Dynaco 416, two of the most brutish of
brute-force amps ever produced at the consumer level - and I find it
quite easy to drive either to clipping on certain passages at not-
quite-headbanging volume. Those who do not understand the power-curve
will _never_ get that sort of thing, and actually believe that a 60-
watt amp is twice as powerful as a 30 watt amp... Draw your own
conclusions.

Peter Wieck
Melrose Park, PA

[Arny Krueger]

"Peter Wieck" wrote in message


I keep a Citation 16 and a Dynaco 416, two of the most
brutish of brute-force amps ever produced at the consumer
level - and I find it quite easy to drive either to
clipping on certain passages at not- quite-headbanging
volume.

First off, the restriction of "consumer level" is artificial. It is
well-known that if you are serious about amplifier power, you slip the surly
bonds of mere household appliances.

By modern standards, either is little more than a peanut-whistle.

Especially the Citation 16. It's only a little more powerful than the amps
in a modern $79 stereo receiver.

The most powerful amp produced at the consumer level that I could find with
a short search was rated at 960 watts into 8 ohm loads.


Those who do not understand the power-curve will
_never_ get that sort of thing, and actually believe that
a 60- watt amp is twice as powerful as a 30 watt amp...


It is twice as powerful, but not twice as loud.

As we both know, twice as loud as a 30 watt amp takes about 300 watts. If
you want some serious amplifier power to play around with, you leave the
world of household appliances behind. A couple of Behringer EP2500s running
bridged into 4 ohm speakers gives you 1300 wpc. Now, you're talking the
beginnings of serious amplifier power.

Draw your own conclusions.

I conclude that a debating trade trick was used to artificially narrow the
field, and that even in that narrowed field, the basic thesis leaves a lot
to be desired.