"RapidRonnie"


What a pile of nonsense!

I'm afraid it's true. Discrete power transistors vary much more than
tubes of a given type and manufacture run.


** Complete bull****.

Power BJTs from the same run are very nearly all identical.

They can be used in parallel just fine.


That's why construction or
repair of high power solid state amps requires either factory-matched
sets or the use of a curve tracer to sort through piles of them.


** You have NO idea what you are talking about.

A curve tracer is just about useless for power BJT matching where parallel
operation is needed.

You need a wide range Vbe / Ic match and that ideally means devices of the
same type, maker and batch.

With power tubes operated in parallel - mating up old and new or differing
brands leads to tears just the same as with BJTs.


Now, MOSFETS are another matter.

The laterals ( aka audio fets) match in parallel very nicely.

The verticals ( aka switching fets) are pigs.




......... Phil

On 4 Jan 2006 17:37:14 -0800, "RapidRonnie"
wrote:


Jim Thompson wrote:
snip
Uh..!? Tubes from different manufacturers are _massively_ better matched
than any two transistors or ICs from the _same batch_!

Tim

What a pile of nonsense!

I'm afraid it's true. Discrete power transistors vary much more than
tubes of a given type and manufacture run. That's why construction or
repair of high power solid state amps requires either factory-matched
sets or the use of a curve tracer to sort through piles of them.

Only because the design sucked in the first place (*). Probably
designed by a "tooobz" engineer ;-)

I have yet to see a single design that demonstrated the proper way to
do a stable A-B bias.

I know how but I ain't talking ;-)


Of course, the transistors come in N and P channel or NPN and PNP
types whereas tubes are not complementary. So it's apples vs. oranges.

Are apples or oranges better?

I like mixed fruit salad myself... apples, oranges, grapes, Kiwi, and
maybe some Pomegranate ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

"Jim Thompson"

I'm afraid it's true. Discrete power transistors vary much more than
tubes of a given type and manufacture run. That's why construction or
repair of high power solid state amps requires either factory-matched
sets or the use of a curve tracer to sort through piles of them.

Only because the design sucked in the first place (*).


** Show how little YOU know about SS amps.


I have yet to see a single design that demonstrated the proper way to
do a stable A-B bias.



** There are a couple of ways that work very well.

Sanken make BJTs with bias diodes on the chips.

http://pdf.alldatasheet.com/datashee...EN/SAP15N.html

Another good way is to use a common emitter output stage.


I know how but I ain't talking ;-)



** Weeeell - any posturing bull**** artist can say that !!




......... Phil

On 4 Jan 2006 14:59:25 -0800, "Bret Ludwig"
wrote:


Ted Edwards wrote:
Tim Williams wrote:
Ya, because they have that fun little exponential Vbe curve. Beta is to
transistors what Gm is to tubes and FETs, and you know it...

I've seen your posts here and elsewhere. They all seem to be of similar
quality. I have been designing, building and _listening to_ audio
amplifiers for about 60 years and the plain fact is that tube amps just
don't do a good job especially at very low or very high frequencies.
Almost acceptable THD is possible at 1 KHz maybe even up to 5 or 10 but
then maybe you can't hear anything above that.

Bull**** on stilts. McIntosh, ARC, Julie Labs and many others have
made tube amps with THD and intermod specs comparable to any popular
solid state and bandwidth up to at least 25 or 30 kHz, surely you can't
hear above that.

Indeed they have, but those are rare and honourable exceptions, and
diametrically opposed to the designs favoured by most in this forum,
which appear to majotr on restricted bandwidth and high distortion. It
must of course also be pointed out that what distinguishes these
excellent tube amps, is that they sound exactly the same as any good
SS amp..............................


Tube amps do a good job from perhaps 16 Hz (they are
down some there usually)

They are down about 10dB typically in power response.........

to 20-22 kHz (and if they are down a little
over 15 kHz that's OK as long as it is not too sudden a slope) and
because the type of distortioon differs. .1 THD is OK on tube amps
whereas .01 may NOT be on solid state.

Hooey, this is typical flimflam uttered by tubies because hardly any
tube amps are *capable* of 0.01% distortion.

Subjectively tube amps of a
given specification often (not always) sound better than solid state
amps of better spec.

In your humble opinion.

Russ Hamm proved it in 1973 with his paper which
appeared in JAES and it has not been contradicted. Arny talks a lot but
he knows it's true and will be until they change the laws of physics.

Hamm's paper was not peer-reviewed, and it was written so long ago
that it is irrelevant to modern amplifiers. The laws of physics have
not changed, but our ability to manufacture excellent SS devices
certainly has.

We got Cal a copy of the book "An Evening with Marilyn" by Douglas
Kirkland for Christmas. There's a hi--fi system in the background in
the loft where the shoot takes place. (Looks like an Altec amp and a
big Altec bass driver-the horns are out of the picture. There's a big
dust cap-it's not a 604....but who would have cared?) You know when
Frank Sinatra, Arthur Miller, JFK, and DiMaggio were on top of THAT
situation the music was playing just fine with no silicon involved. You
know what? It still does. (The music. The people, they're dead.)

So are tube amps..........................

--

Stewart Pinkerton | Music is Art - Audio is Engineering

On 4 Jan 2006 14:09:30 -0800, "Bret Ludwig"
wrote:


Arny Krueger wrote:
wrote in message
ups.com


Today, for practically any purpose that I can imagine in
my home shop, the audio output on my PC sound card rules.

Most PC sound cards vastly outperform legacy audio signal generators, both
for low distortion and flatness. They also have excellent settling times.

A decent voltmeter tells me the output level.

The trick is finding an inexpensive one with good frequency response. My
best meters are Flukes (not cheap) or the ProTek 506 (flat enough but not
wonderful and still not exactly cheap).

No Arny, the trick is to ante up once and buy a good one from a first
or at least second tier manufacturer whose specs well eclipse the job
at hand. Second tier manufacturers are sometimes better because they
use off the shelf parts where Agilent and Tek used their fab
capabilities to make wonderful chips....that no longer exist. And they
are not making more.

If commodisumo PeeCee hardware were test grade National , Aeroflex,
Agilent and others would not be getting the hemmorhoid-splattering
prices they do for CompactPCI and VME/VXI hardware. A peecee is not a
core piece of test equipment. Yes you can do a few things with a sound
card, but a Audio Precision box is NOT a sound card in a fancy box.

Nor does it contain tubes.................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Stewart Pinkerton wrote:

Russ Hamm proved it in 1973 with his paper which
appeared in JAES and it has not been contradicted. Arny talks a lot but
he knows it's true and will be until they change the laws of physics.

Hamm's paper was not peer-reviewed, and it was written so long ago
that it is irrelevant to modern amplifiers. The laws of physics have
not changed, but our ability to manufacture excellent SS devices
certainly has.

Worse still, Hamm considered only a very dated style of a.c. coupled common
emitter transistor amplifer without degeneration and the majority of his
conclusions were about its character when *overdriven * ! Simple. You avoid
'overdriving' !

Graham

"Pooh Bear" wrote
in message

Stewart Pinkerton wrote:

Russ Hamm proved it in 1973 with his paper which
appeared in JAES and it has not been contradicted. Arny
talks a lot but he knows it's true and will be until
they change the laws of physics.

Hamm's paper was not peer-reviewed,

AFAIK, *everything* in the JAES is peer-reviewed. I guess the peers were
also tubies. Either that or they were smokin' some gooooood stuff. Maybe
both. ;-)

and it was written
so long ago that it is irrelevant to modern amplifiers.

The Hamm paper was no doubt obsolete on the day it was written, for many
reasons. One problem I've noticed with it is that it compared the
large-signal distortion of amplifier stages with differing gains. Since the
stage gains differed, the output signals differered dramatically in terms of
amplitude. Hamm thus built his case against SS on the fact that simple SS
amplifier stages tend to have higher stage gain than triode tubes.

The laws of physics have not changed, but our ability to
manufacture excellent SS devices certainly has.

Agreed. Among the first SS test equipment to come out were audio signal
distortion measuring equipment.

Worse still, Hamm considered only a very dated style of
a.c. coupled common emitter transistor amplifer without
degeneration and the majority of his conclusions were
about its character when *overdriven * ! Simple. You
avoid 'overdriving' !

I'd like to find some AES old-timers and get some straight answers about how
a POS like the Hamm paper made it through the JAES review process. The
guilty parties are probably dead and gone by now, so the truth might be
knowable despite the confidentiality of the review process.

Arny Krueger wrote:
"Pooh Bear" wrote
in message

Stewart Pinkerton wrote:

Russ Hamm proved it in 1973 with his paper which
appeared in JAES and it has not been contradicted. Arny
talks a lot but he knows it's true and will be until
they change the laws of physics.

Hamm's paper was not peer-reviewed,

AFAIK, *everything* in the JAES is peer-reviewed.

No, eberything is NOT necessarily peer-reviewed. Engineering reports
aren't necessarily peer-reviewed.

However, Journal articles are.

I guess the peers were
also tubies. Either that or they were smokin' some gooooood stuff. Maybe
both. ;-)
I'd like to find some AES old-timers and get some straight answers about how
a POS like the Hamm paper made it through the JAES review process. The
guilty parties are probably dead and gone by now, so the truth might be
knowable despite the confidentiality of the review process.

Has anyone here actually READ The Hamm article. It woiuld appear
not, as it does NOT support any of the assertions made about.
Consider the precis of the article:

"Engineers and musicians have long debated the question of
tube sound versus transistor sound. Previous attempts to
measure this difference have always assumed linear operation
of the test amplifier. This conventional method of frequency
response, distortion, and noise measurement has shown that
no significant difference exists. This paper, however, points out
that amplifiers are often severely overloaded by signal transients
(THD 30%). Under this condition there is a major difference in
the harmonic distortion components of the amplified signal, with
tubes, transistors, and operational amplifiers separating into
distinct groups"

Let's look at the KEY points of the article:

* Previous attempts to measure this difference have always
assumed linear operation ...

* amplifiers are often severely overloaded by signal transients
(THD 30%).

The article ONLY deals with the amplifiers topologies AT THE TIME,
UNDER CONDITIONS OF SEVERE CLIPPING DISTRTION.

It makes NO claims about the operation under normal conditions.
The implications are quite clear: Clipping results in audibly
different
output from. An early 1970's tube amplifier sounds different than an
early 1970's transistor amplifier WHEN BOTH ARE BEING SEVERELY
CLIPPED SUCH THAT THEY ARE GENERATING 30% THD.

The solution to the problem is NOT to by tubes or transistors. The
answer to the problem is VERY simple:

DON'T CLIP THE AMPLIFIER!

Thus, Hamm's paper supports the reasonable assertion that a 250
watt sollid stats amplifier MUST sound better than a 20 watt tube
aplifier when both are being asked to try to produce more than 20
watts.

Thus, Mr. Ludwig's assertions:

"Subjectively tube amps of a given specification often (not always)
sound better than solid state amps of better spec. Russ Hamm
proved it in 1973 with his paper which appeared in JAES"

is simply not supportable. The ONLY difference that the Hamm paper
deals with is under conditions of sever clipping, which is not
"always,"
it's not even "often" as Mr. Ludwig erroneously claims. Further, his
statement:

"and it has not been contradicted."

Is similarily false, as the following citation suggest:

Monteith, Jr., Dwight O.; Flowers, Richard R.; Hamm, Russell O,
"Transistors Can Sound Better Than Tubes," Vol 25, no. 3,
pp. 116-120; March 1977

What's interesting is Hamm, the author of the paper erroneously
cited by Ludwig, is one of the authors of this paper!

Further, the suggestion by Mr. Krueger that there is something
fundamentally amiss with the article or the reviewers is similarily
off the mark, because if you actually deal with the contents of the
article, you find that it makes reaonable sense: solid state amplifiers
clip differently than tube amplifiers, and for a variety of reasons.

wrote in message
ups.com

Further, the suggestion by Mr. Krueger that there is
something fundamentally amiss with the article or the
reviewers is similarily off the mark, because if you
actually deal with the contents of the article, you find
that it makes reaonable sense: solid state amplifiers
clip differently than tube amplifiers, and for a variety
of reasons.

I raised a specific issue which Mr. Pierce you appear to have intentially
deleted from the post of mine you quoted in your attempt to make it look
like I hadn't read the paper:

"One problem I've noticed with (Hamm's paper) is that it compared the
large-signal distortion of amplifier stages with differing gains. Since the
stage gains differed, the output signals differered dramatically in terms of
amplitude. Hamm thus built his case against SS on the fact that simple SS
amplifier stages tend to have higher stage gain than triode tubes.

As far as the claim that tube and SS amps have differing clipping
characteristics, this is not a given. If this comparison is to be made then
the amps should be as similar as possible, differering *only* in the fact
that one has active devices are tubes and the other has active devices that
are SS.

IOW the amplifiers being comapred should have similar or indentical coupling
and impedance-matching circuitry, simliar or identical kinds of and amounts
of stage gain, overall gain, and NFB, etc. Of course the amplfiiers should
also be based on good design practices.

Both Graham and I have pointed out that Hamm's paper fails to be a true
apples-to-apples comparison of tubed and SS amplifiers on these grounds.
Even if only the clipping characteristics of the equipment were compared,
then the comparison needs to be as close as possible. I see no evidence that
Hamm attempted to hold the relevant parameters as close as reasonably
possible. Therefore, even with the narrow criteria related to clipping
behavior that is stated above, the Hamm paper should have never passed
review by the JAES review board, if it was ever reviewed.

In case the meaning of my comments above is not obvious, any well-designed
power amp is going to be well-biased, have good audio bandwidth and
respectible amounts of NFB whether local or global.

Since the presence of audio transformers introduces many complex factors,
they would likely be eliminated from the SS and tubed equipment that would
be compared.

With these parameters held constant, both tubed and SS amps produce
respectible and very similar square waves when clipped.

Therefore, a study of the audible significance of differences in the
clipping performance of tubed and SS equipment becomes of limited
signficance in an true scientific apples-to-apples comparison. Hamm's paper
didn't represent good science, or good art and should have never been
published in the JAES except as a an example of poor-quality work.

dpierce wrote...
Arny Krueger wrote:
AFAIK, *everything* in the JAES is peer-reviewed.

No, eberything is NOT necessarily peer-reviewed.
Engineering reports aren't necessarily peer-reviewed.

Yes, that was my experience. I published an engineering
report in JAES (from a presentation at the LA convention)
and it was not peer-reviewed. It was on a digital subject
in the mid-70s, so maybe they couldn't find anyone to
review it? :-)

wrote:


I guess the peers were
also tubies. Either that or they were smokin' some gooooood stuff. Maybe
both. ;-)
I'd like to find some AES old-timers and get some straight answers about how
a POS like the Hamm paper made it through the JAES review process. The
guilty parties are probably dead and gone by now, so the truth might be
knowable despite the confidentiality of the review process.

Has anyone here actually READ The Hamm article. It woiuld appear
not, as it does NOT support any of the assertions made about.
Consider the precis of the article:

"Engineers and musicians have long debated the question of
tube sound versus transistor sound. Previous attempts to
measure this difference have always assumed linear operation
of the test amplifier. This conventional method of frequency
response, distortion, and noise measurement has shown that
no significant difference exists. This paper, however, points out
that amplifiers are often severely overloaded by signal transients
(THD 30%). Under this condition there is a major difference in
the harmonic distortion components of the amplified signal, with
tubes, transistors, and operational amplifiers separating into
distinct groups"

Let's look at the KEY points of the article:

* Previous attempts to measure this difference have always
assumed linear operation ...

* amplifiers are often severely overloaded by signal transients
(THD 30%).

The article ONLY deals with the amplifiers topologies AT THE TIME,
UNDER CONDITIONS OF SEVERE CLIPPING DISTRTION.

It makes NO claims about the operation under normal conditions.
The implications are quite clear: Clipping results in audibly
different
output from. An early 1970's tube amplifier sounds different than an
early 1970's transistor amplifier WHEN BOTH ARE BEING SEVERELY
CLIPPED SUCH THAT THEY ARE GENERATING 30% THD.

The solution to the problem is NOT to by tubes or transistors. The
answer to the problem is VERY simple:

DON'T CLIP THE AMPLIFIER!

Thus, Hamm's paper supports the reasonable assertion that a 250
watt sollid stats amplifier MUST sound better than a 20 watt tube
aplifier when both are being asked to try to produce more than 20
watts.


"Don't clip the amplifier" is easy to say, and tough to do. Totally
avoiding amplifier clipping under any and all circumstnaces requires
either active power compression control (i.e. "Power Guard") or a
really, really, really big amplifier, the very small signal performance
of which is usually suspect unless the amplifier is made extremely
heavy and hot and has a very high quiescent power draw. A 20 watt tube
amp that pulls 50 watts at full power is more efficient in practice
than a 250 watt solid state amp that pulls 80 watts quiescent and 500
at full power if either provides the same _subjective_ performance-even
though the solid state amp is more efficent for each watt it puts out.

Thus, Mr. Ludwig's assertions:

"Subjectively tube amps of a given specification often (not always)
sound better than solid state amps of better spec. Russ Hamm
proved it in 1973 with his paper which appeared in JAES"

is simply not supportable. The ONLY difference that the Hamm paper
deals with is under conditions of sever clipping, which is not
"always,"
it's not even "often" as Mr. Ludwig erroneously claims. Further, his
statement:

"and it has not been contradicted."

Is similarily false, as the following citation suggest:

Monteith, Jr., Dwight O.; Flowers, Richard R.; Hamm, Russell O,
"Transistors Can Sound Better Than Tubes," Vol 25, no. 3,
pp. 116-120; March 1977

What's interesting is Hamm, the author of the paper erroneously
cited by Ludwig, is one of the authors of this paper!

Further, the suggestion by Mr. Krueger that there is something
fundamentally amiss with the article or the reviewers is similarily
off the mark, because if you actually deal with the contents of the
article, you find that it makes reaonable sense: solid state amplifiers
clip differently than tube amplifiers, and for a variety of reasons.

First, Hamm's article by title states "transistors _can_ sound better
than tubes", which is sometimes true, not that they "always do" which
we know to be false.

Either vacuum tubes or trnasistors can be used with good results.
However many people still prefer to use vacuum tubes, at least under
certain circumstances.

However, I have not yet read this second Hamm paper, and will endeavor
to do so. It still won't make building tube amps any less
recreationally rewarding, though.

Bret Ludwig wrote:
wrote:
The article ONLY deals with the amplifiers topologies AT THE TIME,
UNDER CONDITIONS OF SEVERE CLIPPING DISTRTION.

"Don't clip the amplifier" is easy to say, and tough to do. Totally
avoiding amplifier clipping under any and all circumstnaces requires
either active power compression control (i.e. "Power Guard") or a
really, really, really big amplifier, the very small signal performance
of which is usually suspect unless the amplifier is made extremely
heavy and hot and has a very high quiescent power draw.

Mr. Ludwig, it is clear that you're not in the least bit interested in
dealing with the content of the article. You never read the article,
that's apparent, and you're making a load of baseless assumptions
completely irrelevant rantings.

A 20 watt tube
amp that pulls 50 watts at full power is more efficient in practice
than a 250 watt solid state amp that pulls 80 watts quiescent and 500
at full power if either provides the same _subjective_ performance-even
though the solid state amp is more efficent for each watt it puts out.

What on earth does this load of abosolute nonsense have to
do with the point? Your rantings are pointless and meaningless.

My statement was VERY simple: ANY 250 watt amp trying to produce
more than 20 watts into a load is going to sound MUCH better than
ANY 20 watt tube amp trying to produce 20 watts into the same load.
That's what the implication of the Hamm article is. You don't even
need a "really really big amplifier" for this to be true: a 50 watt
solid
stat amplifier is going to sound better producing, say, 35 watts than
ANY 20 watt tube aplifier trying to produce 35 watts.

First, Hamm's article by title states "transistors _can_ sound better
than tubes", which is sometimes true, not that they "always do" which
we know to be false.

You demonstrated you didn't have a clue what the first Hamm
article said, and now you want to enhance your already solid
reputation by showing that you haven't a clue about this one either?
Go for it.

Either vacuum tubes or trnasistors can be used with good results.
However many people still prefer to use vacuum tubes, at least under
certain circumstances.

That's NOT what your claim blanket claim was. You claimed that
an article that you never read supported your assertion.

You've made numerous assertions, such as the operation of test
equipment, the peroformance of amplifiers and the contents of
articles, all clearly from a position of minimal if any experience or
knowledge of the topics.

wrote:
snip
Mr. Ludwig, it is clear that you're not in the least bit interested in
dealing with the content of the article. You never read the article,
that's apparent, and you're making a load of baseless assumptions
completely irrelevant rantings.

We obviously are not communicating too well. I feel like I'm in a
scene from "The Misfits" (if you have to ask which one you haven't seen
the movie.).

I have read the first Hamm article under discussion, "Tubes vs.
Transistors". I have not read the second Hamm article and was in fact
ignorant of its existence until about a half hour ago.

Let me go read it.

Frankly my entire thesis is simpler than all this: some people like to
build tube amps! As with model trains, the issue of practicality is
secondary. However, it is my contention that it is not a wholly
onanistic endeavor-the tube amp still functions well and does a certain
job with complete satisfaction.

Bret Ludwig wrote:
wrote:
snip
Mr. Ludwig, it is clear that you're not in the least bit interested in
dealing with the content of the article. You never read the article,
that's apparent, and you're making a load of baseless assumptions
completely irrelevant rantings.

We obviously are not communicating too well.

You have made your own self contradictions quite clear. The
issue is not one of communications, but expertise, or the
obvious lack thereof.

Frankly my entire thesis is simpler than all this: some people like to
build tube amps!

No, you stated the following, quite clearly and unambiguously:

"Subjectively tube amps of a given specification often
(not always) sound better than solid state amps of
better spec. Russ Hamm proved it in 1973 with his
paper which appeared in JAES and it has not been
contradicted."

Nothing in your statement intimates anythong about building
tube amps. Nothing. That thesis, as you stated it above, has
been shown to be incorrect. And if you did read the original
Hamm article, clearly the major point he made failed to stick,
because it was all about the performance of the amplifier
under conditions of severe clipping.

"Bret Ludwig" wrote in message
oups.com...
Frankly my entire thesis is simpler than all this: some people like to
build tube amps! As with model trains, the issue of practicality is
secondary. However, it is my contention that it is not a wholly
onanistic endeavor-the tube amp still functions well and does a certain
job with complete satisfaction.

......to some of those people.
Which of course was never in dispute!

Why those people then have to pretend that there is some *technical*
justification to support their personal preference is another matter
entirely!

MrT.

"Arny Krueger" wrote in message
...
wrote in message
ups.com

Further, the suggestion by Mr. Krueger that there is
something fundamentally amiss with the article or the
reviewers is similarily off the mark, because if you
actually deal with the contents of the article, you find
that it makes reaonable sense: solid state amplifiers
clip differently than tube amplifiers, and for a variety
of reasons.

I raised a specific issue which Mr. Pierce you appear to have intentially
deleted from the post of mine you quoted in your attempt to make it look
like I hadn't read the paper:

"One problem I've noticed with (Hamm's paper) is that it compared the
large-signal distortion of amplifier stages with differing gains. Since
the
stage gains differed, the output signals differered dramatically in terms
of
amplitude. Hamm thus built his case against SS on the fact that simple SS
amplifier stages tend to have higher stage gain than triode tubes.

As far as the claim that tube and SS amps have differing clipping
characteristics, this is not a given. If this comparison is to be made
then the amps should be as similar as possible, differering *only* in the
fact that one has active devices are tubes and the other has active
devices that are SS.

IOW the amplifiers being comapred should have similar or indentical
coupling and impedance-matching circuitry, simliar or identical kinds of
and amounts of stage gain, overall gain, and NFB, etc. Of course the
amplfiiers should also be based on good design practices.

Both Graham and I have pointed out that Hamm's paper fails to be a true
apples-to-apples comparison of tubed and SS amplifiers on these grounds.
Even if only the clipping characteristics of the equipment were compared,
then the comparison needs to be as close as possible. I see no evidence
that Hamm attempted to hold the relevant parameters as close as reasonably
possible. Therefore, even with the narrow criteria related to clipping
behavior that is stated above, the Hamm paper should have never passed
review by the JAES review board, if it was ever reviewed.

In case the meaning of my comments above is not obvious, any well-designed
power amp is going to be well-biased, have good audio bandwidth and
respectible amounts of NFB whether local or global.

Since the presence of audio transformers introduces many complex factors,
they would likely be eliminated from the SS and tubed equipment that would
be compared.

With these parameters held constant, both tubed and SS amps produce
respectible and very similar square waves when clipped.

Therefore, a study of the audible significance of differences in the
clipping performance of tubed and SS equipment becomes of limited
signficance in an true scientific apples-to-apples comparison. Hamm's
paper didn't represent good science, or good art and should have never
been published in the JAES except as a an example of poor-quality work.

So what it really boils down to is not tubes vs. transistors, but
transformered vs. transformerless! :-)
(and all of the design pattern differences such a concept entails)

"Don't clip the amplifier" is easy to say, and tough to do. Totally
avoiding amplifier clipping under any and all circumstnaces requires
either active power compression control (i.e. "Power Guard") or a
really, really, really big amplifier, the very small signal performance
of which is usually suspect unless the amplifier is made extremely
heavy and hot and has a very high quiescent power draw. A 20 watt tube
amp that pulls 50 watts at full power is more efficient in practice
than a 250 watt solid state amp that pulls 80 watts quiescent and 500
at full power if either provides the same _subjective_ performance-even
though the solid state amp is more efficent for each watt it puts out.

I guess it depends on what you are doing with the amplifier. In a live venue
or a recording studio, where you have no idea in advance of what the signal
levels are going to be, I would agree with you.

At home, level matching everything from the CD player to the volume control
guarantees that my power amp will not clip until the preamp is turned up at
least 1/2 way. That setting is well above my comfort level.

On 5 Jan 2006 13:22:32 -0800, "Bret Ludwig"
wrote:


wrote:


I guess the peers were
also tubies. Either that or they were smokin' some gooooood stuff. Maybe
both. ;-)
I'd like to find some AES old-timers and get some straight answers about how
a POS like the Hamm paper made it through the JAES review process. The
guilty parties are probably dead and gone by now, so the truth might be
knowable despite the confidentiality of the review process.

Has anyone here actually READ The Hamm article. It woiuld appear
not, as it does NOT support any of the assertions made about.
Consider the precis of the article:

"Engineers and musicians have long debated the question of
tube sound versus transistor sound. Previous attempts to
measure this difference have always assumed linear operation
of the test amplifier. This conventional method of frequency
response, distortion, and noise measurement has shown that
no significant difference exists. This paper, however, points out
that amplifiers are often severely overloaded by signal transients
(THD 30%). Under this condition there is a major difference in
the harmonic distortion components of the amplified signal, with
tubes, transistors, and operational amplifiers separating into
distinct groups"

Let's look at the KEY points of the article:

* Previous attempts to measure this difference have always
assumed linear operation ...

* amplifiers are often severely overloaded by signal transients
(THD 30%).

The article ONLY deals with the amplifiers topologies AT THE TIME,
UNDER CONDITIONS OF SEVERE CLIPPING DISTRTION.

It makes NO claims about the operation under normal conditions.
The implications are quite clear: Clipping results in audibly
different
output from. An early 1970's tube amplifier sounds different than an
early 1970's transistor amplifier WHEN BOTH ARE BEING SEVERELY
CLIPPED SUCH THAT THEY ARE GENERATING 30% THD.

The solution to the problem is NOT to by tubes or transistors. The
answer to the problem is VERY simple:

DON'T CLIP THE AMPLIFIER!

Thus, Hamm's paper supports the reasonable assertion that a 250
watt sollid stats amplifier MUST sound better than a 20 watt tube
aplifier when both are being asked to try to produce more than 20
watts.


"Don't clip the amplifier" is easy to say, and tough to do. Totally
avoiding amplifier clipping under any and all circumstnaces requires
either active power compression control (i.e. "Power Guard") or a
really, really, really big amplifier, the very small signal performance
of which is usually suspect unless the amplifier is made extremely
heavy and hot and has a very high quiescent power draw. A 20 watt tube
amp that pulls 50 watts at full power is more efficient in practice
than a 250 watt solid state amp that pulls 80 watts quiescent and 500
at full power if either provides the same _subjective_ performance-even
though the solid state amp is more efficent for each watt it puts out.

Actually, it's a piece of **** if you're using CD as a source, since
you can set system gain to sit just below clipping for 0dB FS from the
CD. That's what I do with my '50 watt' Krell.


--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 6 Jan 2006 13:02:48 +1100, "Mr.T" MrT@home wrote:


"Bret Ludwig" wrote in message
roups.com...
Frankly my entire thesis is simpler than all this: some people like to
build tube amps! As with model trains, the issue of practicality is
secondary. However, it is my contention that it is not a wholly
onanistic endeavor-the tube amp still functions well and does a certain
job with complete satisfaction.

.....to some of those people.
Which of course was never in dispute!

Why those people then have to pretend that there is some *technical*
justification to support their personal preference is another matter
entirely!

Ever notice how many tubies also prefer vinyl? It's a whole retro
thang, combined with the notion that if it involves more work and more
expense, it must necessarily have higher performance.

Like entropy, nostalgia isn't what it used to be............
--

Stewart Pinkerton | Music is Art - Audio is Engineering

RapidRonnie wrote:

Pooh Bear wrote:
Bret Ludwig wrote:

Subjectively tube amps of a
given specification often (not always) sound better than solid state
amps of better spec. Russ Hamm proved it in 1973 with his paper which
appeared in JAES and it has not been contradicted.

Not contradicted ? It's crock of bull. It was out of date in its methodology and
conclusions even before it was printed.

It may or may not be a crock, but no one has submitted a rebutting
paper to the AES for consideration in 32 years. So I am inclined to
believe it myself.

I don't think anyone bothered on account of the original paper simply being so stupid.

No-one of consequence paid any attention to it and quite right too.

The Hamm paper is flawed through and through.

Graham

Karl Uppiano wrote:

So what it really boils down to is not tubes vs. transistors, but
transformered vs. transformerless! :-)
(and all of the design pattern differences such a concept entails)

Actually no.

How did you arrive at that conclusion ?

Graham

Stewart Pinkerton wrote:

Actually, it's a piece of **** if you're using CD as a source, since
you can set system gain to sit just below clipping for 0dB FS from the
CD. That's what I do with my '50 watt' Krell.

Very true.

If you knew the settings for the cutter lathe you could do the same for vinyl too,
despite some audiophools not understanding this point ( they think it has unlimited
dynamic range it seems ! ).

Graham

Bret Ludwig wrote:

"Don't clip the amplifier" is easy to say, and tough to do.

No !

It's ridiculously simple in fact.

Graham

On Fri, 06 Jan 2006 07:12:51 +0000, Pooh Bear
wrote:



Stewart Pinkerton wrote:

Actually, it's a piece of **** if you're using CD as a source, since
you can set system gain to sit just below clipping for 0dB FS from the
CD. That's what I do with my '50 watt' Krell.

Very true.

If you knew the settings for the cutter lathe you could do the same for vinyl too,
despite some audiophools not understanding this point ( they think it has unlimited
dynamic range it seems ! ).

Graham

But it is different for every disc - the point with CD is that you can
set it once and forget it.

d

Pearce Consulting
http://www.pearce.uk.com

Bret Ludwig wrote:

"Don't clip the amplifier" is easy to say, and tough to do.

Wrong. It's easy if you know how.

Totally
avoiding amplifier clipping under any and all circumstnaces requires
either active power compression control (i.e. "Power Guard")

Not necessarilily. What's this 'power guard' anyway ? Some audiophoolery I expect.
Pro-audio amps have had signal limiters to avoid clipping for *decades*. Including
the cutting lathe amplifiers that made the vinyl !

or a
really, really, really big amplifier,

That helps for sure. :-)

the very small signal performance
of which is usually suspect unless the amplifier is made extremely
heavy and hot and has a very high quiescent power draw. A 20 watt tube
amp that pulls 50 watts at full power is more efficient in practice
than a 250 watt solid state amp

That's a pure lie. Tube amplifiers are staggeringly inefficient.


First, Hamm's article by title states "transistors _can_ sound better than tubes",
which is sometimes true, not that they "always do" which we know to be false.

How do you know ? Personal bias ?

Graham

Don Pearce wrote:

On Fri, 06 Jan 2006 07:12:51 +0000, Pooh Bear
wrote:



Stewart Pinkerton wrote:

Actually, it's a piece of **** if you're using CD as a source, since
you can set system gain to sit just below clipping for 0dB FS from the
CD. That's what I do with my '50 watt' Krell.

Very true.

If you knew the settings for the cutter lathe you could do the same for vinyl too,
despite some audiophools not understanding this point ( they think it has unlimited
dynamic range it seems ! ).

Graham

But it is different for every disc - the point with CD is that you can
set it once and forget it.

CD makes it simpler for sure since there is a clearly defined 'brick wall'.

Just pointing out that vinyl doesn't have some supposed infinite headroom.

Graham

"Don Pearce" wrote in message
...
But it is different for every disc - the point with CD is that you can
set it once and forget it.

Since the cartridge you use has it's trackability limits, and the cutter
lathes also have their limits, there is still a finite limit to what you
will ever get from a vinyl disk. This can be ascertained.
OTOH, CD's have differing average levels, so you cannot "set and forget",
only ascertain the peak level setting for clipping for Dfs.
Admittedly the peak levels on all modern CD's come close to this, whereas
the peak levels for individual vinyl disks cover a wide range.
Knowing the maximum gain setting in both cases allows you to set a volume
control level below the maximum required for amplifier induced clipping
however.

MrT.

Bret Ludwig wrote:

Arny Krueger wrote:
snip
If you use them a lot, the tubes wear out.

This is why they still make'em.

There
are no proprietary parts that are likely to wear out with
normal use.

Tubes have always been proprietary parts. OK, you HP 200C has say a 6SN7 in
it. Which manufacturer's 6SN7 is the right one to use?

My experience is the box works with any of them. Probably one yields
best case distortion or dial tracking. I have never had it be an issue.

The tube-bigot lie here is that most ICs in good audio test equipment are
standard parts, or can be readily replaced with standard parts.

IIRC the 8903 has a proprietary diff amp that is close to unobtanium.
HP solid state RF gens use a lot of proprietary silicon-8640s are
slowly dropping, which is a shame, they are the low phase noise
solution even today. The Ollies couldn't copy this stuff on their own,
or they would-they need Western capital and management. Too bad, I'd
love seeing Agilent hoist by their own 35 year old petard!

Audio Precision test oscillators offer THD residuals in the 0.0006% region (
-104dB )

Not a toob in sight !

Graham

Arny Krueger wrote:

In fact audio generators with rediculously low residiuals have been made
using nothing more exotic than NE 5532s.

I may shortly be diving inside our AP test set ( backlight needs replacing )
.. Dunno what they use actually. Maybe some exotic PMI or AD parts in
selected places ?

Graham

"Mr.T" wrote:

"Don Pearce" wrote in message
...
But it is different for every disc - the point with CD is that you can
set it once and forget it.

Since the cartridge you use has it's trackability limits, and the cutter
lathes also have their limits, there is still a finite limit to what you
will ever get from a vinyl disk.

Spot on !

This can be ascertained.
OTOH, CD's have differing average levels, so you cannot "set and forget",
only ascertain the peak level setting for clipping for Dfs.

Not sure what you're saying. It's certainly easy to set up a listening system
that simply won't clip from a CD source. The *CD* may be clipped of course
but that's an entirely different matter.


Admittedly the peak levels on all modern CD's come close to this, whereas
the peak levels for individual vinyl disks cover a wide range.
Knowing the maximum gain setting in both cases allows you to set a volume
control level below the maximum required for amplifier induced clipping
however.

Correct.

Graham

"Bret Ludwig" wrote in message
oups.com

"Don't clip the amplifier" is easy to say, and tough to
do.

Nonsense. People do it all the time.

Totally avoiding amplifier clipping under any and all
circumstnaces

A totally ludicrous goal. In the real world enough can be known about the
initial requirements that clipping can generally be avoided.

requires either active power compression
control (i.e. "Power Guard")

Compression is not a solution because it has its own set of audible
consequences.

or a really, really, really big amplifier,

By the ca. 1960 standards of tube bigots, really really big amplifers are
now readily available.

the very small signal performance of which
is usually suspect unless the amplifier is made extremely
heavy and hot and has a very high quiescent power draw.

Total nonsense.

A 20 watt tube amp that pulls 50 watts at full power is
more efficient in practice than a 250 watt solid state
amp that pulls 80 watts quiescent and 500 at full power
if either provides the same _subjective_ performance-even
though the solid state amp is more efficent for each watt
it puts out.

There's no way that a 20 watt tube amp can sound better than a 500 watt amp,
if the situation requires much more than 20 watts. While tube enthusiasts
like to posture about how their hobby-horse amps sound as good if not better
than far larger SS amps, back in the real world an hi fi amp that is
clipping sounds bad no matter what its active devices are.

First, Hamm's article by title states "transistors _can_
sound better than tubes", which is sometimes true, not
that they "always do" which we know to be false.

This is just more senseless posturing. Of course a sweeping generality can
be false under some situations. So what?

Either vacuum tubes or trnasistors can be used with good
results. However many people still prefer to use vacuum
tubes, at least under certain circumstances.

There are enough people listening to amplifiers that the "many people (who)
still prefer to use vacuum tubes" is a miniscule and shrinking minority.

However, I have not yet read this second Hamm paper, and
will endeavor to do so. It still won't make building tube
amps any less recreationally rewarding, though.

I thought this was about technology, not recreation.

"Pooh Bear" wrote
in message

Stewart Pinkerton wrote:

Actually, it's a piece of **** if you're using CD as a
source, since you can set system gain to sit just below
clipping for 0dB FS from the CD. That's what I do with
my '50 watt' Krell.

Very true.

If you knew the settings for the cutter lathe you could
do the same for vinyl too, despite some audiophools not
understanding this point ( they think it has unlimited
dynamic range it seems ! ).

Setting levels for vinyl playback or transcription is similarly pretty easy.

Get a trackbility test LP such as the one from Hi Fi News and set levels so
that you can play the highest trackable segment while leaving a few dB for
headroom throrgh the electronics. It's really a similar thing to the
procedure that was suggested for a system with a CD player.

"Pooh Bear" wrote
in message
Bret Ludwig wrote:

"Don't clip the amplifier" is easy to say, and tough to
do.

Wrong. It's easy if you know how.

Totally
avoiding amplifier clipping under any and all
circumstnaces requires
either active power compression control (i.e. "Power
Guard")

Not necessarilily. What's this 'power guard' anyway ?

An electronic circuitry that backs off the amplifier's gain when the input
signal would tend to push it into clipping.

http://www.mcintoshlabs.com/mcprod/....%5CMC602br.pdf

"Power Guard® clipping protection. Power Guard ensures that the amplifier
will always deliver full power without causing clipping distortion. If an
amplifier channel is overdriven, Power Guard automatically reduces the input
volume just enough to keep distortion below 2% and prevent any clipping
distortion. Thanks to an optical resistor, Power Guard acts literally at the
speed of light, producing absolutely no audible side effects. An amplifier
with Power Guard will actually deliver clipping-free output well above its
rated power."

Some audiophoolery I expect. Pro-audio amps have had
signal limiters to avoid clipping for *decades*.
Including the cutting lathe amplifiers that made the
vinyl !

Vinyl bigots would die if they knew about all the work-arounds that were
routinely used in its production.


or a
really, really, really big amplifier,

That helps for sure. :-)

the very small signal performance
of which is usually suspect unless the amplifier is made
extremely
heavy and hot and has a very high quiescent power draw.
A 20 watt tube amp that pulls 50 watts at full power is more efficient
in practice than a 250 watt solid state amp

That's a pure lie. Tube amplifiers are staggeringly
inefficient.


Bret is also implicitly claiming that a 20 watt tubed amp can sound as good
as a 500 watt amp when 500 watts would be required to avoid clipping. This
is complete and total nonsense.


First, Hamm's article by title states "transistors _can_
sound better than tubes", which is sometimes true, not
that they "always do" which we know to be false.

How do you know ? Personal bias ?

It's what the voices in his head tell him. I think he should unwrap the
aluminum foil from around his cranium.

"Pooh Bear" wrote
in message

Arny Krueger wrote:

In fact audio generators with rediculously low
residiuals have been made using nothing more exotic than
NE 5532s.

Various construction projects like this have been published in the past,
including one by me. There was also a far more elaborate project by Cordell
that was published in Audio Magazine.

If one works with building audio generators of the traditional analog kind,
it turns out that the nonlinearity of the means used to stabilize the levels
is the major source of distortion, not the amplifier portion of the
oscillator. This is true whether a light bulb, a CdS opto-isolator, a
thermistor, a FET or a VCA is used. Been there and done that for all of
them.

I may shortly be diving inside our AP test set (
backlight needs replacing ) . Dunno what they use
actually. Maybe some exotic PMI or AD parts in selected
places ?

Maybe even discrete op amps, depending on the age.

One relevant parameter is the maximum amplitude that is provided. One
classic benchmark maximum output in the 10 vrms or +22 range. To provide
this at the generator's output terminals @600 ohms, you have to have a few
dB more at the op amp's output terminals.

You can't really do this with +/- 15 or +/- 18 supplies. One can stretch
NE5532s to +/- 22 but they tend to degrade over years.

The only high-voltage op amp chip that I know (one that shows signs of
hanging in with +/- 22) of is the OPA 604/2604. According to Doug Self,
they vastly underperform NE 5532s for nonlinear distortion.

Modern DAC chips are so good, and digital computation and function
management is so cheap and pervasive, that a modern sound card in a PC is
the most practical way to generate well-controlled sine waves these days.

It takes a lot of work to outperform a M-Audio Audiophile 24192 driven by
simple freeware software like Audacity and/or Audio Rightmark.

"Pooh Bear" wrote
in message
Bret Ludwig wrote:

Arny Krueger wrote:
snip
If you use them a lot, the tubes wear out.

This is why they still make'em.

There
are no proprietary parts that are likely to wear out
with normal use.

Tubes have always been proprietary parts. OK, you HP
200C has say a 6SN7 in it. Which manufacturer's 6SN7 is
the right one to use?

My experience is the box works with any of them.
Probably one yields best case distortion or dial
tracking. I have never had it be an issue.

The tube-bigot lie here is that most ICs in good audio
test equipment are standard parts, or can be readily
replaced with standard parts.

IIRC the 8903 has a proprietary diff amp that is close
to unobtanium. HP solid state RF gens use a lot of
proprietary silicon-8640s are slowly dropping, which is
a shame, they are the low phase noise solution even
today. The Ollies couldn't copy this stuff on their own,
or they would-they need Western capital and management.
Too bad, I'd love seeing Agilent hoist by their own 35
year old petard!

Audio Precision test oscillators offer THD residuals in
the 0.0006% region ( -104dB )

I looped-back a little XP PC with an Audiophile 24192 in it the other day,
running the freeware Audio Rightmark Program. *All* spurious responses were
112 dB or better down (most in the -120 dB range), and THD+N was something
like -106 dB.

Not a toob in sight !

AFAIK toobed audio generators and analyzers never got within 2-3 orders of
magnitude of -106 dB residuals. Something like 0.05% midband, and 0.1% at 20
and 20 KHz was about as far as toobs got.

When the first generation SS audio test equipment like the HP 331-334
first hit the market, residuals *instantly* improved by like an order of
magnitude.

http://mywebpages.comcast.net/mnowlen/hp334a.htm

Heath made a cheap clone of this box (IM5258) that I was able to improve so
that it had mid-band residuals in the 0.001-0.003% range.

"Pooh Bear" wrote in message
...
OTOH, CD's have differing average levels, so you cannot "set and
forget",
only ascertain the peak level setting for clipping for Dfs.

Not sure what you're saying.

Simply that the apparent SPL level will be different using different CD's in
a "set and forget" position regardless of Dfs.
I think it's simply bad terminology saying "set and forget". It is actually
ascertaing the *maximum* gain setting, and one *often* varies the system
gain below that level.

It's certainly easy to set up a listening system
that simply won't clip from a CD source.

Which I agreed with, vinyl too. Also FM etc.

The *CD* may be clipped of course

Nearly all are these days.

but that's an entirely different matter.

Quite so.

MrT.

Arny Krueger wrote:
"Pooh Bear" wrote
Audio Precision test oscillators offer THD residuals in
the 0.0006% region ( -104dB )

I looped-back a little XP PC with an Audiophile 24192 in it the other day,
running the freeware Audio Rightmark Program. *All* spurious
responses were 112 dB or better down (most in the -120 dB range),
and THD+N was something like -106 dB.

Not a toob in sight !

AFAIK toobed audio generators and analyzers never got within 2-3
orders of magnitude of -106 dB residuals. Something like 0.05%
midband, and 0.1% at 20 and 20 KHz was about as far as toobs got.

The biggest problem with low residuals back then was not, in my
experience, wether they used tubes or solid state, rather on how well
the unit was stabilized. There was a Krohn-Hite tubed oscillator, as I
recall, that was easily capable of well below 0.003% , you just had to
let it sit there and stabilize. AT the same time, some of the GR solid
state oscillators, like the 1309, could be tuned to meet those kinds of
levels, and MIGHT have been capable of far better, but the amplitude
stabilization network just just too noisy: you'd watch the residual
bouncing around and every once in a while you'd see it drop a good
20 dB below its average for a brief period (about a second). Bang the
case, upset the filament in the bulb they used for stabilization, and
you'd see the residual go all over the place.

The real secret to low-residual oscillators came with much better ,
lower noise and faster responding loop stabilization. The original
ST1700
had an oscillator circuit not substantially different than whatever
else was
out there but had superior stabilization and that was the secret to
their
significantly lower residual.

Arny Krueger wrote:

When the first generation SS audio test equipment like the HP 331-334
first hit the market, residuals *instantly* improved by like an order of
magnitude.

http://mywebpages.comcast.net/mnowlen/hp334a.htm

Heath made a cheap clone of this box (IM5258) that I was able to improve so
that it had mid-band residuals in the 0.001-0.003% range.

Neat !

Do you fancy posting any more info about that ?

Graham

"Pooh Bear" wrote
in message
Arny Krueger wrote:

When the first generation SS audio test equipment like
the HP 331-334 first hit the market, residuals
*instantly* improved by like an order of magnitude.

http://mywebpages.comcast.net/mnowlen/hp334a.htm

Heath made a cheap clone of this box (IM5258) that I
was able to improve so that it had mid-band residuals in
the 0.001-0.003% range.

Neat !

Do you fancy posting any more info about that ?

Once upon a time I wrote an outline of an article about it for Ed Dell, but
lost interest in his ragazine due to his negative stance on ABX before
getting much furhter with it.

I still have the modded 5258 packed away someplace. I fired it up about a
year ago and it still worked. It was a real POS compared to what I now do
with PCs. Hard to operate, limited reporting, relatively high residuals.

The mod development work revealed some interesting stuff.

One of the more significant zero-cost enhanments involved taking a grounding
problem out of the power supply circuit card that flooded the whole box with
low-level ripple. Bad land pattern design around the power supply caps.

Part of the mod involved replacing one or two discrete transistor stages
with 5534s.

I had to up the gain of the measurement circuits by about 20 dB to make the
lower residuals useful. There was a 10/20 dB gain boost switch that the mod
added.

I had to work over some time constants in the nulling circuit, and make them
change for the lower frequency ranges. That was controlled by a second added
front-panel switch.

The box was noisy because it had immense bandwidth - something like 4-5 MHz
at -3 dB. To get the lowest residuals a switchable low-pass filter was added
to the metering circuit.

On Fri, 06 Jan 2006 07:12:51 +0000, Pooh Bear
wrote:



Stewart Pinkerton wrote:

Actually, it's a piece of **** if you're using CD as a source, since
you can set system gain to sit just below clipping for 0dB FS from the
CD. That's what I do with my '50 watt' Krell.

Very true.

If you knew the settings for the cutter lathe you could do the same for vinyl too,
despite some audiophools not understanding this point ( they think it has unlimited
dynamic range it seems ! ).

Yes, but there's a massive variation in maximum groove velocity, from
say EMI 'Music for Pleasure' at one end, to the Sheffield Track and
Drum records at the other. Setting your system gain to avoid clipping
at 30cm/sec will make for very quiet listening to most commercial
output!
--

Stewart Pinkerton | Music is Art - Audio is Engineering