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

Pooh Bear wrote:
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 ?

Never actually worked on one BUT ....(at a prev employer) our Portable
One Plus had the same issue. I had read somewhere there was a Cherry
display which was pin compatible with the LCD (or at least very likely
there was) and have bitched often at the readability issues with the
LCD. It turned out there WAS and they (the metrology guys) used that
instead and it is far more readable IMO. A heads-up.

I'll try to find a part number for you. They sent a note to AP so they
may know.

Pooh Bear wrote:
Bret Ludwig wrote:

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

Not a toob in sight !

AP offers their oscillator only with their test set whgich starts at
about $7000-8000 new. A good used 200CD or its relatives is $25-50 in
working shape. Also, although the AP's gen is cleaner, it won't put the
level into the loads the HP will. And the HP will survive hobbyist and
student oopses for decades. With the AP you can kill it by walking over
a dry enough carpet and grabbing a test lead! I was a witness to that
one (it was the analyzer rather than the gen side that died-AP fixed it
gratis, but it was JUST back from cal.)

Arny Krueger wrote:
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.

Your debating petard has hoist you as usual. My claim was based on the
idea that when listening to classical music at normal room volumes
through a speaker of particular efficiency, (where I don't know what
efficiency that is the author-it might have been PWK or an employee
thereof), the average power might be two to five watts, with peak
overloads that a 20-watt tube amplifier would render listenably clipped
whereas to be similarly undistracting (to say nothing of not killing
tweeters) a 250 watt (output) solid state amplifier would be needed. A
Class B amplifier is of roughly 50 percent efficiency and so I figured
500 watts power consumption. A 20 watt Class AB tube amplifier might
at most pull fifty watts, depending on its Class A power point and
heater draw. Therefore, as anyone can see, the solid state amplifier
has better power efficiency, but, the tube amp at 50 watts pulls less
power than the SS amp at 500 (at full output) or even 80 (I speculated
its quiescent draw.) to do what to the human listener is "the same
job". My numbers may be a little off but anyone but you would get the
concept.

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.

That ought to be self-evident.

"Richard Crowley" bravely wrote to "All" (05 Jan 06 10:52:44)
--- on the heady topic of " THD claims of audio signal generators"

RC From: "Richard Crowley"
RC Xref: core-easynews rec.audio.tech:186148
RC sci.electronics.design:537334 sci.electronics.repair:354106


RC 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.

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

Transistor amplifiers in the mid 70's were pieces of crap. They had no
idea what they were doing with respect to TIM and other time domain
anomalies. Often transistor amplifiers of that vintage would oscillate
ultrasonically and infrasonically when overloaded and it caused really
odd sonic artifacts that nobody realized or understood back then.

It really was a matter that transistor amps were basically
unpredictable when they clipped and tube amps generally behaved
nicely. This erratic behaviour was probably due to the comparatively
radical amounts of negative feedback used in transistor amps. Back
then, it was like comparing apples and oranges.

Fast forward the discussion 30 years into the future to today...
The real discussion should be if they both sound different under
linear operation? Musically I hear a difference but most might not.

A*s*i*m*o*v

.... A stereo system is the altar to the god of music.

"Pooh Bear" wrote in message
...


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.

What? No explanation? Just no?

How did you arrive at that conclusion ?

It was a tongue-in-cheek response to Arny's comments. That was what the
":-)" thingie was all about. However, I think it is rather pointless to
compare two circuits that are as completely different as a direct-coupled,
transformerless transistor power amp and a typical iron-laden tube amp. I
would expect a direct-coupled, transformerless tube amp to sound much more
like a transistor amp, if such a design is even practical.

"Stewart Pinkerton" wrote in message
...
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!

Are you saying that just because most modern CD's have peak levels very
close to Dfs, you *always* listen to them at the exact same peak SPL, day or
night?
Or do you actually use the volume control like most people, based on your
knowledge of recorded levels and the system gain structure that you have
already ascertained?

I simply refuse to believe that more than a handful of people do actually
"set and forget" the volume control, even with CD.

MrT.

"Bret Ludwig" wrote in message
ups.com...
My numbers may be a little off

Agreed!
(assuming a rather broad definition for "little" :-)

MrT.

On Sat, 7 Jan 2006 17:37:45 +1100, "Mr.T" MrT@home wrote:


"Stewart Pinkerton" wrote in message
.. .
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!

Are you saying that just because most modern CD's have peak levels very
close to Dfs, you *always* listen to them at the exact same peak SPL, day or
night?

No, but I know where to set the volume control (-6dB, to be precise)
to *ensure* no clipping.

Or do you actually use the volume control like most people, based on your
knowledge of recorded levels and the system gain structure that you have
already ascertained?

Yes.

I simply refuse to believe that more than a handful of people do actually
"set and forget" the volume control, even with CD.

Me, too! :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering

In article QfGvf.1104$em5.335@trnddc05,
Karl Uppiano wrote:
[....]
I would expect a direct-coupled, transformerless tube amp to sound much
more like a transistor amp,

I've heard one and it sounded very good, if that's what you mean.

if such a design is even practical.

It isn't.

--
--
forging knowledge

Bret Ludwig wrote:

"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.

Do what? First of all, there will be many conditions where the 20 watt
amplifier will be well into gross clipping while the 250 watt amp is
loafing along. Next, even assuming 50% final stage efficiency, which
is a stretch for most tube implementations, there's no way in hell the
tube amp will draw merely 50 watts at full output.

Let's assume 6BQ5s - they'll deliver 17 watts wound out, but that's in
the ball park and we want to use the lowest-dissipation tube for this
examination: each tube's filament eats 6.3 volts at 0.76 amps, so a pair
takes 1.5 amps at 6.3 volts. That's another 10 watts there, plus another
10 or so for the driver and input stage heaters, not to mention 20 more
watts for all the quiescent currents. Things are starting to heat up,
which is pretty obvious to anyone who's spent much time with tube amps.
At this point we're talking close to 40 watts quiescent for this 20 watt
tube amp, so it's about 80 watts maxed out. Now let's look at a 250 watt
transistor amp: the rails will be at +- 50 volts (full power @ 4 ohms), so
comparing apples to apples and setting quiescent dissipation at 40 watts
(less a third for the drivers et al) means you get a output stage bias of
250 milliamperes. Not huge, but not bad either.


On the other hand, even assuming Hamm's paper is still relevant 32 years
after publishing and several generations of amplifier designs since,
and comparing amplifiers which he claims would have more-or-less equal
resistance to overload, 60 watt tube amps have a quiescent dissipation
around 70 to 90 watts: that would bias the SS output stage at 0.7 ampere.
Note this is enough to maintain class-A operation into several watts.
The extra dissipation all goes into the output stage, as opposed to
warming up an armada of tube heaters; one could argue that a transistor
amplifier dissipating as much heat as a tube amp half its size uses
that heat more efficiently!


In any event, the core of the argument here is not so much the thermal
efficiency of various amplifiers (which is a hell of a way to defend
tubes), but how they _sound_, and I can come up with any number of
scenarios for which a 20 watt amp, no matter how liquid its midrange*,
will be Not Enough.

* which I suspect is a function not of transfer characteristics but
more of non-zero output impedance changing frequency response when
driving a loudspeaker.


Francois.

"Karl Uppiano" wrote in message
news:QfGvf.1104$em5.335@trnddc05

However, I
think it is rather pointless to compare two circuits that
are as completely different as a direct-coupled,
transformerless transistor power amp and a typical
iron-laden tube amp. I would expect a direct-coupled,
transformerless tube amp to sound much more like a
transistor amp, if such a design is even practical.

Whether any tubed hifi amp design is practical is open for debate, but only
if the tubie wants to lose the debate.

In fact a goodly number of transformerless tubed audio amps have been built
and sold

http://www.atma-sphere.com/reviews/ga/

http://stereophile.com/tubepoweramps/997graaf/

http://members.aol.com/aria3/

http://www.one-electron.com/Fourier.html

http://www.transcendentsound.com/T8OTL.htm

Here are some schematics:

http://www.one-electron.com/Fourier/FC_SPmk3.pdf

http://www.mcmlv.org/Archive/HiFi/OTL1.pdf

http://www.mcmlv.org/Archive/HiFi/OTL3.pdf

"(null)"

Do what? First of all, there will be many conditions where the 20 watt
amplifier will be well into gross clipping while the 250 watt amp is
loafing along. Next, even assuming 50% final stage efficiency, which
is a stretch for most tube implementations, there's no way in hell the
tube amp will draw merely 50 watts at full output.



** Just for the record:

The final stage efficiency of a *class B* amp is NOT a number but a curve
on a graph.

The *maximum* efficiency, with sine wave drive and a resistive load, is
78.5 % and occurs at full output swing ( rail to rail).

At 1/2 power, efficiency falls to 55%.

At 1/10th power it is 24 %.

At 1/100th power it is only 8% !

So, a 100 watt class B amp dissipates over 12 watts when delivering only 1
watt to the load ( aside form any idle dissipation due to the bias setting).


OTOH:

A class A amplifier has a maximum efficiency of 50% at full power.

So, a 100 watt class A amp will dissipate 100 watts when delivering 100
watts.

At 1/100th power, efficiency falls to a mere 0.5% !!

It will dissipate 199 watts when delivering 1 watt !!!!





.......... Phil

On Sat, 07 Jan 2006 03:01:14 GMT, "Asimov"
wrote:


Transistor amplifiers in the mid 70's were pieces of crap. They had no
idea what they were doing with respect to TIM and other time domain
anomalies. Often transistor amplifiers of that vintage would oscillate
ultrasonically and infrasonically when overloaded and it caused really
odd sonic artifacts that nobody realized or understood back then.



I was working as a repair tech in a stereo store back then and one day
someone brought in one of those Marantz $1000 receivers with the
little Oscope in the corner for the FM tuner. We plugged it in and
all the techs working there stopped and commented that it was a damn
good sounding receiver.

Funny thing is, you really can hear a difference sometimes.

You'll know it when you hear it.

Bret Ludwig wrote:
Arny Krueger wrote:
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.

Your debating petard has hoist you as usual.

Watch which petard you have in your own back pocket, Mr. Ludwig,
a'fore you make such comments.

My claim was based on the
idea that when listening to classical music at normal room volumes
through a speaker of particular efficiency, (where I don't know what
efficiency that is the author-it might have been PWK or an employee
thereof), the average power might be two to five watts,

You made absolutely NO such claim, Mr. Ludwig. You're claim was
VERY simple, unambiguous and wrong:

"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."

Hamm's article makes NO such claim, it deals SPECIFICALLY
with operation under conditions of sever clipping when THD
amounts are on the order of 30%.

with peak
overloads that a 20-watt tube amplifier would render listenably clipped
whereas to be similarly undistracting (to say nothing of not killing
tweeters) a 250 watt (output) solid state amplifier would be needed.

Absolute nonsense. Hamm's article makes no such statement.
You have not provided a single shred of evidence to support such
a claim.

Further, NO one here ever made such a claim, save you. The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound MUCH
better than ANY 20 watt tube amplifier when both are being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35 watts than
a 20 watt tube amplifier trying to do 35 watts,.

A
Class B amplifier is of roughly 50 percent efficiency and so I figured
500 watts power consumption.

So what? What on earth does class B operation have to do with it,
since almost NO audio amplifier since that time ran class B. There
is but one or two such examples, and all are LONG off the market.

Further, what on earth does power consumption and efficiency
have to do with it?

A 20 watt Class AB tube amplifier might
at most pull fifty watts,

Just like a class AB solid state amplifier, which comprises MOST
of the solid state amplifiers on the market. The only difference is
the SS amplfiier doesn't have to provide power for filaments..


Therefore, as anyone can see, the solid state amplifier
has better power efficiency, but, the tube amp at 50 watts pulls less
power than the SS amp at 500 (at full output) or even 80 (I speculated
its quiescent draw.) to do what to the human listener is "the same
job".

This is utter and completely irrelevant claptrap, Mr. Ludwig. We're
not talking about efficiency, we're simply dealing with the fact that
ANY higher power amplifier will sound better than any LOWER power
power amplifier when trying to produce more power than the lower
power amplifier is capable. It has nothing to do with bias class, it
has nothing to do with amplfiier efficiency.

My numbers may be a little off

Your numbers are WAY off and completely irrelevant.

but anyone but you would get the concept.

The concept that is clear is that you made a specific claim which
was wrong:

"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."

and now you're making further claims which have only
solidified the fact that you were wrong to begin with.

That ought to be self-evident.

What is evident is either your inability or dogged refusal to deal
with the fundamental tecnnical errors behind your assertions, not
to mention the fact that your cited an article which utterly fails to
support your, ahem, "thesis."

"Bret Ludwig" wrote in message
oups.com...
As an aside Jim Williams of Linear Technology has written very
intelligent pieces on HP Wien-bridge oscillators and building an
improved solid state version. I doubt it is on the web but you may be
better at finding it than me.

I have it, actually. It's in a book published by Newnes, isn't it?

I may have given the wrong HP part number. (Didn't I say 204C? I think
that's right.) It's transistorized and does not contain a light bulb.

"Bret Ludwig" wrote in message
oups.com

As an aside Jim Williams of Linear Technology has written
very intelligent pieces on HP Wien-bridge oscillators and
building an improved solid state version. I doubt it is
on the web but you may be better at finding it than me.

The name of the article is:

"Max Wien, Mr. Hewlett and a Rainy Sunday Afternoon", included in the book
"Analog Circuit Design: Art, Science and Personalities" . See Amazon, etc.

wrote:
snip

Further, NO one here ever made such a claim, save you. The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound MUCH
better than ANY 20 watt tube amplifier when both are being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35 watts than
a 20 watt tube amplifier trying to do 35 watts,.


I wholly agree. However what happens when both are asked to deliver
2000 watts? But only for a very miniscule time, and average putting
out, say, 500 mW? Given sufficient crest factor of the material and
sufficiently efficient speakers that is actually a possible (if very
extreme case) scenario. It's the case McIntosh, the purveyors of
specmanship themselves, made, and very well, with the advent of their
first high power solid state amplifier. It is they who IMO have hoist
themselves by their own petard!


A
Class B amplifier is of roughly 50 percent efficiency and so I figured
500 watts power consumption.

So what? What on earth does class B operation have to do with it,
since almost NO audio amplifier since that time ran class B. There
is but one or two such examples, and all are LONG off the market.

Further, what on earth does power consumption and efficiency
have to do with it?

Actually very little, juice is cheap.

A 20 watt Class AB tube amplifier might
at most pull fifty watts,

Just like a class AB solid state amplifier, which comprises MOST
of the solid state amplifiers on the market. The only difference is
the SS amplfiier doesn't have to provide power for filaments..

Yes, that filament power is a deal-breaker. How many watts do four
6L6s and six 12AT7s pull?



Therefore, as anyone can see, the solid state amplifier
has better power efficiency, but, the tube amp at 50 watts pulls less
power than the SS amp at 500 (at full output) or even 80 (I speculated
its quiescent draw.) to do what to the human listener is "the same
job".

This is utter and completely irrelevant claptrap, Mr. Ludwig. We're
not talking about efficiency, we're simply dealing with the fact that
ANY higher power amplifier will sound better than any LOWER power
power amplifier when trying to produce more power than the lower
power amplifier is capable. It has nothing to do with bias class, it
has nothing to do with amplfiier efficiency.

My numbers may be a little off

Your numbers are WAY off and completely irrelevant.

but anyone but you would get the concept.

The concept that is clear is that you made a specific claim which
was wrong:

"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."

and now you're making further claims which have only
solidified the fact that you were wrong to begin with.

That ought to be self-evident.

What is evident is either your inability or dogged refusal to deal
with the fundamental tecnnical errors behind your assertions, not
to mention the fact that your cited an article which utterly fails to
support your, ahem, "thesis."

To the extent you never clip your amp, that is true. Hamm et al dealt
not at all with reasons for hobbyists (not studio owners) in 2006 (not
1973) to build their own tube boxes, like the satisfaction of the job
and the appearance of the glowing tubes (which has gotten more than one
audiophile laid more tha once, I'd wager...)

Bret Ludwig wrote:

wrote:
snip

Further, NO one here ever made such a claim, save you. The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound MUCH
better than ANY 20 watt tube amplifier when both are being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35 watts than
a 20 watt tube amplifier trying to do 35 watts,.

I wholly agree. However what happens when both are asked to deliver
2000 watts? But only for a very miniscule time, and average putting
out, say, 500 mW?

A 36dB transient ? You are joking yes ?

Graham

On Tue, 10 Jan 2006 02:25:09 +0000, Pooh Bear
wrote:



Bret Ludwig wrote:

wrote:
snip

Further, NO one here ever made such a claim, save you. The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound MUCH
better than ANY 20 watt tube amplifier when both are being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35 watts than
a 20 watt tube amplifier trying to do 35 watts,.

I wholly agree. However what happens when both are asked to deliver
2000 watts? But only for a very miniscule time, and average putting
out, say, 500 mW?

A 36dB transient ? You are joking yes ?

Graham

Any recording medium saturates at a reasonable, but not extreme, level
above average program level, CDs run out of bits, vinyl runs out of
groove width, mag tape saturates, even live FM is deviation limited.

John

"John Larkin"

Any recording medium saturates at a reasonable, but not extreme, level
above average program level, CDs run out of bits, vinyl runs out of
groove width, mag tape saturates, even live FM is deviation limited.



** = exactly why you do not get 36 dB peaks above average on commercial
music recordings.




.......... Phil

On Tue, 10 Jan 2006 02:25:09 +0000, Pooh Bear
wrote:

Bret Ludwig wrote:

wrote:
snip

Further, NO one here ever made such a claim, save you. The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound MUCH
better than ANY 20 watt tube amplifier when both are being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35 watts than
a 20 watt tube amplifier trying to do 35 watts,.

I wholly agree. However what happens when both are asked to deliver
2000 watts? But only for a very miniscule time, and average putting
out, say, 500 mW?

A 36dB transient ? You are joking yes ?

No, he's simply thrashing about in defence of a lost argument - as
usual.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Phil Allison" wrote in message
...
** = exactly why you do not get 36 dB peaks above average on commercial
music recordings.

Hell, you are very unlikely to find peaks more than 10dB above average on
most disks these days.

MrT.

"Bret Ludwig" wrote in message
oups.com
wrote:
snip

Further, NO one here ever made such a claim, save you.
The
statement was VERY simpe: ANY solid state amplifier with
substantially more power than 20 watts is going to sound
MUCH
better than ANY 20 watt tube amplifier when both are
being asked
to deliver more than 20 watts.

That means a 50 watt SS amplifier will do better at 35
watts than
a 20 watt tube amplifier trying to do 35 watts,.

I wholly agree. However what happens when both are asked
to deliver 2000 watts?

You fry the speaker.

Get real!

"Phil Allison" wrote in message

"John Larkin"

Any recording medium saturates at a reasonable, but not
extreme, level above average program level, CDs run out
of bits, vinyl runs out of groove width, mag tape
saturates, even live FM is deviation limited.

** = exactly why you do not get 36 dB peaks above
average on commercial music recordings.

Its even pretty hard to find 36 dB peaks in live performances.

Every once in a while someone drops, or unplugs, or heavily bumps a mic at
one of the preformances I record. This is *always* the biggest peak in the
recording. IOW, the whole recording chain has enough dynamic range to handle
*anything* that actually happens along the lines of music.

Arny Krueger wrote:
"Bret Ludwig" wrote in message
oups.com
wrote:
That means a 50 watt SS amplifier will do better at 35
watts than a 20 watt tube amplifier trying to do 35 watts,.
I wholly agree. However what happens when both are asked
to deliver 2000 watts?

You fry the speaker.

And, in the case of his little 20 watt tube amplifier, even if there
was
that much energy in the power supply and the plate resistance were
damned near 0, the output transformers would have long since
saturated.

Get real!

He can't: his argument falls apart, and he can't have that, can he?

wrote in message
oups.com...

Arny Krueger wrote:
"Bret Ludwig" wrote in message
oups.com
wrote:

That means a 50 watt SS amplifier will do better at 35
watts than a 20 watt tube amplifier trying to do 35 watts,.
I wholly agree. However what happens when both are asked
to deliver 2000 watts?

You fry the speaker.

And, in the case of his little 20 watt tube amplifier, even if there was
that much energy in the power supply and the plate resistance were
damned near 0, the output transformers would have long since
saturated.

I believe the tubie argument is that between being able to put out say 80
watt peaks and the euphonic nature of tube clipping, the 20 watt amp could
be asked to deliver 2000 watt peaks every few milliseconds, and the
listeners would be pleased.

Get real!

He can't: his argument falls apart, and he can't have that, can he?

I think that "Bret Ludwig" is just another alias for a Luddite troll that's
been around here for years. So, not even the poster is real.

In , on 01/06/06
at 06:37 PM, "Mr.T" MrT@home said:

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.

[ ... ]

Yes, as far as the signal is concerned, but if the cartridge crosses a
scratch or some dirt, there can be a large transient. Some phono
preamps take quite a while to recover from one of these transient
events.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

I think any discussion of tubes transistors and distortion should be
tempered with an appreciation of the historic shift in design
techniques.

For example, undergraduate 1950's and 1960's tube designers didn't have
Root Locus in their tool bag. They used feedback gingerly and
empirically. The transistor guys were fresh out of school, had Root
Locus, and would pour on the feedback. The little detail about SID was
mostly overlooked till about 1980.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
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"Barry Mann" wrote in message
om...
In , on 01/06/06
at 06:37 PM, "Mr.T" MrT@home said:

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.

[ ... ]

Yes, as far as the signal is concerned, but if the cartridge crosses a
scratch or some dirt, there can be a large transient. Some phono
preamps take quite a while to recover from one of these transient
events.

Only the very poorly designed ones. But I'm uncertain why you are worried
about the amplifier distortion levels caused by a "scratch or some dirt".
The whole transient itself is distortion. One reason why I always hated
vinyl.

MrT.

In , on 01/15/06
at 12:14 PM, "Mr.T" MrT@home said:




"Barry Mann" wrote in message
. com...
In , on 01/06/06
at 06:37 PM, "Mr.T" MrT@home said:

Yes, as far as the signal is concerned, but if the cartridge crosses a
scratch or some dirt, there can be a large transient. Some phono
preamps take quite a while to recover from one of these transient
events.

Only the very poorly designed ones. But I'm uncertain why you are
worried about the amplifier distortion levels caused by a "scratch or
some dirt". The whole transient itself is distortion. One reason why I
always hated vinyl.

If the preamp bumbles for a while, the event lasts longer than it needs
to.

In some respects you can have a similar situation with CD players. A
relatively minor (from a data recovery or error concealment point of
view) bald spot on the disc can cause the transport to bumble around so
long while attempting to reacquire the track that it runs out of data
and the audio must mute. Had the transport been able to coast through
the bald spot, there would have been no audible problem.

My point being that a design shortcoming causes more audible damage
than necessary.

I agree that tic, pop, wow, and tracing distortion are a bummer.

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spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
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"Barry Mann" wrote in message
om...
I think any discussion of tubes transistors and distortion should be
tempered with an appreciation of the historic shift in design
techniques.

For example, undergraduate 1950's and 1960's tube designers didn't have
Root Locus in their tool bag.

I learned root locus stability analysis in the mid-60s.

This page references a text from that time:

http://www.cbu.edu/~rprice/lectures/rootlocus.html

Coughanowr's book came out in 1965. Coughanowr received his PhD in 1956, so
any precident-setting paper was probably published in the preceeding 15 or
so years.

In , on 01/15/06
at 03:17 PM, "Arny Krueger" said:

"Barry Mann" wrote in message
. com...
I think any discussion of tubes transistors and distortion should be
tempered with an appreciation of the historic shift in design
techniques.

For example, undergraduate 1950's and 1960's tube designers didn't have
Root Locus in their tool bag.

I learned root locus stability analysis in the mid-60s.

This page references a text from that time:

http://www.cbu.edu/~rprice/lectures/rootlocus.html

Coughanowr's book came out in 1965. Coughanowr received his PhD in
1956, so any precident-setting paper was probably published in the
preceeding 15 or so years.

I think that it was Bode and crew at Bell Labs during the 1940's that
developed the ground work. I can remember a Knight Kit tube amplifier
of about 1960 that was advertised as being unconditionally stable.
Then, it was a unique product. A few years later I learned exactly what
that meant, but at the time I did appreciate that I did not need to
fuss about accidentally unloading the output.

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spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------