Thanks to all who contributed to the last smps thread. This is a
response delayed by a protracted struggle with the siren voices of
anarchism as I fled my first encounter with EU regulations.
Discipline restored, I realise that as a European I can't sustain my
moral leadership of the new world order whilst consuming 120W in
producing an average 2W of music.

The main advantage of SM is efficiency. Although it was primarily
necessitated by considerations of convenience (small, cool, powerful
devices), efficiency for the sake of conservation is increasingly a
concern of social conscience, and hence will continue to creep into
legislation. We could argue that we only represent a squillienth of
world consumption, but this is like a burglar pleading not guilty on
account of not being a murderer. We could argue that our amps are
only 30% efficient anyway, but then the burglar is pleading on the
ground that burglary is nothing compared to the murder he hasn't
been charged with.

Efficiency is also an interesting pursuit for a "hobbyist", as the
"professionals" call us amateurs. After all, there is bugger all to
get excited about in the audio sections of a valve amp. It is also a
practical concern even for valve amps in situations where weight or
heat output is important, such as in a studio or portable rack.

Then there is the power factor issue, also one of social
responsibility. At the time of my original post I was not aware of
the formal definition of power factor where the waveforms are not
simple sine waves (cos phi when they are).

Actually the full definition of power factor includes distortion as
well as phase difference. Hence the "current gulping" habit of
C-input supplies is just as much a part of the power factor as is
the phase lead of the current (er...I think...).

A simple linear supply with LC-input is a cumbersome and expensive
option, has its own design and execution problems, and only
addresses the power factor problem.

Just as the transformer can be shrunk by increasing its frequency of
operation in a SMPS, so the L of a LC-input supply can be shrunk if
it is switched at high frequency. Switched mode power factor
correction can use a small L switched into the C. Not much point
perhaps with a linear supply because if all the HF mess has to be
cleaned up anyway, you may as well go the whole hog and switch the
whole caboodle.

I asked because I had been messing with a forward converter, and
ended up in a shambles. Simulation was hard enough, especially as
inductor models are so problematic in spice, and the combination of
low and high frequencies is tiresome. Easy to get the right voltage,
efficiency and regulation one at a time, but not all at once.
Practical experiments quickly demonstrate further that once you mix
in the parasitics and quirks of real devices, the only way to avoid
total carnage is to copy a standard solution.

The claim that you need to understand switchers in order to design
them is pure bull****. The principles are not hard to grasp, and the
practical problems of layout and specific device behaviour are
largely beyond the grasp of useful understanding. Experience is much
more important, which is one reason I asked. But the really
important thing the "professionals" have over the amateur is
industry intelligence, safety in number, conference, seminar, plump
for a semiconductor and chip set, cling to the application notes and
keep a straight face whilst muddling through with the layout and
inductors.

For the most entertaining intro I have found, check out Fairchild's
guides. You have to register, but they are well-behaved and worth
it. There is a link to a brilliantly mumbled audio-visual on power
factor correction strategies, and a summary of the requirements of
EU legislation (similar will creep everywhere eventually), including
a succinct definition of PF.

http://www.fairchildsemi.com/whats_new/acdc.html

Mostly flyback. I was surprised that the only respondent actually
using SM went for a boost converter. Perhaps I was barking up the
wrong tree with my forward converter attempt...why?

cheers, Ian

PS

In case it's hard to find...re power factor correction:

http://www.fairchildsemi.com/an/AN/AN-42047.pdf

cheers

Ian

"Ian Iveson" wrote in message
. ..
Thanks to all who contributed to the last smps thread. This is a
response delayed by a protracted struggle with the siren voices of
anarchism as I fled my first encounter with EU regulations.
Discipline restored, I realise that as a European I can't sustain my
moral leadership of the new world order whilst consuming 120W in
producing an average 2W of music.

The main advantage of SM is efficiency. Although it was primarily
necessitated by considerations of convenience (small, cool, powerful
devices), efficiency for the sake of conservation is increasingly a
concern of social conscience, and hence will continue to creep into
legislation. We could argue that we only represent a squillienth of
world consumption, but this is like a burglar pleading not guilty on
account of not being a murderer. We could argue that our amps are
only 30% efficient anyway, but then the burglar is pleading on the
ground that burglary is nothing compared to the murder he hasn't
been charged with.

Efficiency is also an interesting pursuit for a "hobbyist", as the
"professionals" call us amateurs. After all, there is bugger all to
get excited about in the audio sections of a valve amp. It is also a
practical concern even for valve amps in situations where weight or
heat output is important, such as in a studio or portable rack.

Then there is the power factor issue, also one of social
responsibility. At the time of my original post I was not aware of
the formal definition of power factor where the waveforms are not
simple sine waves (cos phi when they are).

Actually the full definition of power factor includes distortion as
well as phase difference. Hence the "current gulping" habit of
C-input supplies is just as much a part of the power factor as is
the phase lead of the current (er...I think...).

A simple linear supply with LC-input is a cumbersome and expensive
option, has its own design and execution problems, and only
addresses the power factor problem.

Just as the transformer can be shrunk by increasing its frequency of
operation in a SMPS, so the L of a LC-input supply can be shrunk if
it is switched at high frequency. Switched mode power factor
correction can use a small L switched into the C. Not much point
perhaps with a linear supply because if all the HF mess has to be
cleaned up anyway, you may as well go the whole hog and switch the
whole caboodle.

I asked because I had been messing with a forward converter, and
ended up in a shambles. Simulation was hard enough, especially as
inductor models are so problematic in spice, and the combination of
low and high frequencies is tiresome. Easy to get the right voltage,
efficiency and regulation one at a time, but not all at once.
Practical experiments quickly demonstrate further that once you mix
in the parasitics and quirks of real devices, the only way to avoid
total carnage is to copy a standard solution.

The claim that you need to understand switchers in order to design
them is pure bull****. The principles are not hard to grasp, and the
practical problems of layout and specific device behaviour are
largely beyond the grasp of useful understanding. Experience is much
more important, which is one reason I asked. But the really
important thing the "professionals" have over the amateur is
industry intelligence, safety in number, conference, seminar, plump
for a semiconductor and chip set, cling to the application notes and
keep a straight face whilst muddling through with the layout and
inductors.

For the most entertaining intro I have found, check out Fairchild's
guides. You have to register, but they are well-behaved and worth
it. There is a link to a brilliantly mumbled audio-visual on power
factor correction strategies, and a summary of the requirements of
EU legislation (similar will creep everywhere eventually), including
a succinct definition of PF.

http://www.fairchildsemi.com/whats_new/acdc.html

Mostly flyback. I was surprised that the only respondent actually
using SM went for a boost converter. Perhaps I was barking up the
wrong tree with my forward converter attempt...why?

cheers, Ian

Switchers are not good for audio because they are noisy

(1) they have a noisy output
(2) they broadcast noise that could enter the circuit through stray I and C.

COS switchers are unreliable because they run the caps at near maximum
rating. Any flaw in the cap and it blows.

When one takes into account the hazardous waste generated by computer type
garbage and the energy and waste generated to make new ones the simple
linear PS may turn out to be more efficient than first thought. In the
winter it helps heat the house.

This is my perspective of the issue. Good luck with the NWO. Mark

"truegridtz" wrote in message
...


Switchers are not good for audio because they are noisy

(1) they have a noisy output

**Really? You'd better let these guys know, quick smart:

http://www.halcro.com/home.asp Check out the S/N ratio of their products.
You should also check out almost every budget DVD player on the planet. Most
use SMPS and demonstrate S/N ratios well in excess of 100dB. Can you name
any linear PS tube amps which can provide those kinds of numbers?

(2) they broadcast noise that could enter the circuit through stray I and
C.

**More nonsense. Look at the above site. I just ran some numbers on my sound
card. It is a humble Sound Blaster and exhibits a S/N ratio in excess of
106dB. Not bad, considering it is powered by a AUS$20.00 SMPS.


COS switchers are unreliable because they run the caps at near maximum
rating. Any flaw in the cap and it blows.

**SMPS are less reliable than linear PS. And that is certainly mostly down
to electrolytic caps.


When one takes into account the hazardous waste generated by computer type
garbage and the energy and waste generated to make new ones the simple
linear PS may turn out to be more efficient than first thought. In the
winter it helps heat the house.

**The wastefulness of Linear PS is vastly over-stated. Only when regulation
is required, do SMPS really shine. For an unregulated PS, you can figure on
around 90% efficiency for a decent linear PS. I'd be far more bothered by
all those wasteful filaments.


This is my perspective of the issue. Good luck with the NWO. Mark

**And your perspective appears to be substantially in error.


--
Trevor Wilson
www.rageaudio.com.au

"Ian Iveson" wrote in message
. ..
Thanks to all who contributed to the last smps thread. This is a response
delayed by a protracted struggle with the siren voices of anarchism as I
fled my first encounter with EU regulations. Discipline restored, I
realise that as a European I can't sustain my moral leadership of the new
world order whilst consuming 120W in producing an average 2W of music.

**Then dump Class A, single ended and tube amps. Move to more efficient
designs, using switching amplification.


The main advantage of SM is efficiency.

**ONLY if regulation is desired. For an unregulated supply, linear PS are
excellent. Figure on around 90% for quality designs, using quality iron.
SMPS main advantage lies with it's low cost, in high volume products and for
those designs where regulation is important. It is in the area of regulation
where the most engery can be wasted in a linear design.

Although it was primarily
necessitated by considerations of convenience (small, cool, powerful
devices), efficiency for the sake of conservation is increasingly a
concern of social conscience, and hence will continue to creep into
legislation. We could argue that we only represent a squillienth of world
consumption, but this is like a burglar pleading not guilty on account of
not being a murderer. We could argue that our amps are only 30% efficient
anyway, but then the burglar is pleading on the ground that burglary is
nothing compared to the murder he hasn't been charged with.

**Then move to switching amplifiers using MOSFETs. FAR more efficient.
Figure on around 90% efficiency for such designs. The differences between
linear and SMPS is pitifully tiny, by comparison.


--
Trevor Wilson
www.rageaudio.com.au

"Trevor Wilson" wrote in message
...

"truegridtz" wrote in message
...


Switchers are not good for audio because they are noisy

(1) they have a noisy output

**Really? You'd better let these guys know, quick smart:

http://www.halcro.com/home.asp Check out the S/N ratio of their products.
You should also check out almost every budget DVD player on the planet.

The whole dang planet?

Most
use SMPS and demonstrate S/N ratios well in excess of 100dB. Can you name
any linear PS tube amps which can provide those kinds of numbers?

I certainly hope not.



(2) they broadcast noise that could enter the circuit through stray I
and
C.

**More nonsense. Look at the above site.

I looked at it. Three feet of crap about some weird amp. Is that one of
those chopper amps? Digital has been a lie from day one. It still doesn't
work right and it probably never will. It sounds butchered and the
distortion figures are exceptionally low. Distortion figures are almost
always skewed bull**** from whoever is trying to sell something. You might
take the time to notice that they usually pick the most favorable frequency
to analyze.

I just ran some numbers on my sound
card. It is a humble Sound Blaster and exhibits a S/N ratio in excess of
106dB. Not bad, considering it is powered by a AUS$20.00 SMPS.

Ran some numbers? What the hell do you know about being humble? You've
been reading Stereophile haven't you? I suppose you used your raging ego as
a reference. Did you see the article about one of those monstrous
turntables that could only put out the lowest lows if one bought the
optional platter bearing heater? How about the $700 "mono" cartridges that
have two coils? Crap runs like a river and you seem to eat bowls of it.
You ran some numbers on your SoundBlaster? What the hell.




COS switchers are unreliable because they run the caps at near maximum
rating. Any flaw in the cap and it blows.

**SMPS are less reliable than linear PS. And that is certainly mostly down
to electrolytic caps.


When one takes into account the hazardous waste generated by computer
type
garbage and the energy and waste generated to make new ones the simple
linear PS may turn out to be more efficient than first thought. In the
winter it helps heat the house.

**The wastefulness of Linear PS is vastly over-stated. Only when
regulation
is required, do SMPS really shine. For an unregulated PS, you can figure
on
around 90% efficiency for a decent linear PS. I'd be far more bothered by
all those wasteful filaments.

If you are so bothered by waste why don't you go find some idiot driving a
polluting pile of crap and tune it up for him? One junk car wastes hundreds
of times more energy than a few tube filaments. There is also the raw fuel
going into the atmosphere.


This is my perspective of the issue. Good luck with the NWO. Mark

**And your perspective appears to be substantially in error.


--
Trevor Wilson
www.rageaudio.com.au

And you seem to believe every thing you read. Ran some numbers on your
SoundBlaster. That's really good.

I just ran some numbers on my stereo. Wow, it's kickin' ass. Thanks for
showing me how to use this sound card. I had no idea that it was also a
sound lab.

Rage on, Trevor. You're damned good at it, but you don't seem to know much
more than the crap you read in brochures.

Worried about those wasteful filaments? Sheeeeat. All you are worried
about is finding a place to kick your next fit. Please go somewhere else,
and take your switcher with you.

Ran some numbers on my soundblaster, what a crock.

Trevor Wilson wrote:

"Ian Iveson" wrote in message
. ..
Thanks to all who contributed to the last smps thread. This is a response
delayed by a protracted struggle with the siren voices of anarchism as I
fled my first encounter with EU regulations. Discipline restored, I
realise that as a European I can't sustain my moral leadership of the new
world order whilst consuming 120W in producing an average 2W of music.

**Then dump Class A, single ended and tube amps. Move to more efficient
designs, using switching amplification.

It'd be better to dump yourself.

Recycling facilities mightn't accept the trevor wilsons of this world though....

The latest switching amps I have seen will soon make all the present
large SS amps operating in mainly class B seem quite obsolete, since the
switching amps with their
95% efficiency don't ever get hot, and are cheaper to make than existing SS
amps, and the new D amps
will sound at least as good as the all the existing SS junk that has not been
any sonic improvement
over the best of the tube gear made, so exit Krell, Gryphon, ME, Halcro etc.
I doubt anyone will be able to buy a "normal" SS analog amp anywhere in 15
years.
The makers will have all switched to switchers, with switching arguments about
who uses the nicest
switching parts and switching waves. Whoopy.


Meanwhile, we all know tubes are hear to stay inspite of what gee whiz SS crap
that the audio industry may try to foist upon us.

The inefficiencies of a tube amp pale into insignificance when we examine
the whole of our lives, and the fact that despite the human progress we have
made,
we find ourselves still using about 20 Kgs of coal a day, for every
man woman and child.

Even if we had power causing no greenhouse effects, and costing nothing, our
species will still be in trouble
long term, because with free energy, there will be an increased amount of demand
for
goods and services that ppl want in their lives, ie, we'd each have a kingly or
queenly
existance if it were possible, a bigger car, and a house with 25 bathrooms.
So the forests will dissappear faster, the ecology messing up and exitinction
rate will quicken,
and sooner or later the planet will become very ugly.

If the cost of living is reduced with cheaper power and greater efficiencies
then all that leads to is more consumption of just about everything,
and since demand is the only thing that the world that will never run out of,
we will still cause our own decline, if history is any guide.

As regards SMPS for tube amps, I searched the web for some ready made
PSU with +500v at 1 amp, short circuit proof, and with 6.3v at 20 amps,
but no such luck, so I'd have to R&D one up.

But why? the SMPS isn't more efficient that I now make.

It is lighter though, and a 300VA PC SMPS is a lot lighter than a linear
PS of the same VA.

A tube amp is always going to be heavy if it uses a linear OPT,
so may as well make a heavy linear PS.

Where Halcro has used SMPS in their amps, it seems to have worked OK,
but unfortunately, they have an extremely
inefficient price, some aud $45,000 for a pair.

SMPS cannot make an amp sound any better.

Patrick Turner.







The main advantage of SM is efficiency.

**ONLY if regulation is desired. For an unregulated supply, linear PS are
excellent. Figure on around 90% for quality designs, using quality iron.
SMPS main advantage lies with it's low cost, in high volume products and for
those designs where regulation is important. It is in the area of regulation
where the most engery can be wasted in a linear design.

Although it was primarily
necessitated by considerations of convenience (small, cool, powerful
devices), efficiency for the sake of conservation is increasingly a
concern of social conscience, and hence will continue to creep into
legislation. We could argue that we only represent a squillienth of world
consumption, but this is like a burglar pleading not guilty on account of
not being a murderer. We could argue that our amps are only 30% efficient
anyway, but then the burglar is pleading on the ground that burglary is
nothing compared to the murder he hasn't been charged with.

**Then move to switching amplifiers using MOSFETs. FAR more efficient.
Figure on around 90% efficiency for such designs. The differences between
linear and SMPS is pitifully tiny, by comparison.

--
Trevor Wilson
www.rageaudio.com.au

truegridtz wrote:

"Trevor Wilson" wrote in message
...

"truegridtz" wrote in message
...


Switchers are not good for audio because they are noisy

(1) they have a noisy output

**Really? You'd better let these guys know, quick smart:

http://www.halcro.com/home.asp Check out the S/N ratio of their products.
You should also check out almost every budget DVD player on the planet.

The whole dang planet?

Most
use SMPS and demonstrate S/N ratios well in excess of 100dB. Can you name
any linear PS tube amps which can provide those kinds of numbers?

I certainly hope not.


(2) they broadcast noise that could enter the circuit through stray I
and
C.

**More nonsense. Look at the above site.

I looked at it. Three feet of crap about some weird amp. Is that one of
those chopper amps? Digital has been a lie from day one. It still doesn't
work right and it probably never will. It sounds butchered and the
distortion figures are exceptionally low. Distortion figures are almost
always skewed bull**** from whoever is trying to sell something. You might
take the time to notice that they usually pick the most favorable frequency
to analyze.

The Halcro is a class AB mosfet analog amp and has astonishingly
low thd figures. The brand has been around for years now, and everyone knows
the facts about the low thd.
Its something like 0.0001% at 200 watts and at 20kHz when most other SS amps
have 0.01%
at 200 watts, maybe.
Presumably they use a lot of negative feedback.

Halcros may look weird, but they are not weird, they are just modern electronic
engineering.
They do have SMPS, but the amps themselves are not digital amps.

As the Hong Kong audio club said of Halcro,
" Ah, Halcro, it like 300B, but go louder. "





I just ran some numbers on my sound
card. It is a humble Sound Blaster and exhibits a S/N ratio in excess of
106dB. Not bad, considering it is powered by a AUS$20.00 SMPS.

Ran some numbers? What the hell do you know about being humble? You've
been reading Stereophile haven't you? I suppose you used your raging ego as
a reference. Did you see the article about one of those monstrous
turntables that could only put out the lowest lows if one bought the
optional platter bearing heater? How about the $700 "mono" cartridges that
have two coils? Crap runs like a river and you seem to eat bowls of it.
You ran some numbers on your SoundBlaster? What the hell.



COS switchers are unreliable because they run the caps at near maximum
rating. Any flaw in the cap and it blows.

**SMPS are less reliable than linear PS. And that is certainly mostly down
to electrolytic caps.


When one takes into account the hazardous waste generated by computer
type
garbage and the energy and waste generated to make new ones the simple
linear PS may turn out to be more efficient than first thought. In the
winter it helps heat the house.

**The wastefulness of Linear PS is vastly over-stated. Only when
regulation
is required, do SMPS really shine. For an unregulated PS, you can figure
on
around 90% efficiency for a decent linear PS. I'd be far more bothered by
all those wasteful filaments.

If you are so bothered by waste why don't you go find some idiot driving a
polluting pile of crap and tune it up for him? One junk car wastes hundreds
of times more energy than a few tube filaments. There is also the raw fuel
going into the atmosphere.


This is my perspective of the issue. Good luck with the NWO. Mark

**And your perspective appears to be substantially in error.


--
Trevor Wilson
www.rageaudio.com.au

And you seem to believe every thing you read. Ran some numbers on your
SoundBlaster. That's really good.

I just ran some numbers on my stereo. Wow, it's kickin' ass. Thanks for
showing me how to use this sound card. I had no idea that it was also a
sound lab.

Rage on, Trevor. You're damned good at it, but you don't seem to know much
more than the crap you read in brochures.

Worried about those wasteful filaments? Sheeeeat. All you are worried
about is finding a place to kick your next fit. Please go somewhere else,
and take your switcher with you.

Ran some numbers on my soundblaster, what a crock.

Ok, you can put the revolver down now, and stop waving it around.
You'll make trev more nervous than he is already after ****ting in the
r.a.t loungeroom.
Take a break.

There are some ppl who have not got everything, but they have a lotta money
and they like the most modern thing with the most bestest specifications.
Halcro provide exactly what such people want, so good luck to them.

But unless one has lived with a Halcro amp system for awhile, one wouldn't
know if they are nice amps or not.
They'd wanna sound ok for $45,000.

Patrick Turner.

"truegridtz" wrote in message
...

"Trevor Wilson" wrote in message
...

"truegridtz" wrote in message
...


Switchers are not good for audio because they are noisy

(1) they have a noisy output

**Really? You'd better let these guys know, quick smart:

http://www.halcro.com/home.asp Check out the S/N ratio of their products.
You should also check out almost every budget DVD player on the planet.

The whole dang planet?

**Yep.


Most
use SMPS and demonstrate S/N ratios well in excess of 100dB. Can you name
any linear PS tube amps which can provide those kinds of numbers?

I certainly hope not.



(2) they broadcast noise that could enter the circuit through stray I
and
C.

**More nonsense. Look at the above site.

I looked at it. Three feet of crap about some weird amp. Is that one of
those chopper amps?

**Nope. A regular linear amp, with a SMPS.

Digital has been a lie from day one. It still doesn't
work right and it probably never will.

**Utter, ill-informed nonsense.

It sounds butchered and the
distortion figures are exceptionally low. Distortion figures are almost
always skewed bull**** from whoever is trying to sell something. You
might
take the time to notice that they usually pick the most favorable
frequency
to analyze.

I just ran some numbers on my sound
card. It is a humble Sound Blaster and exhibits a S/N ratio in excess of
106dB. Not bad, considering it is powered by a AUS$20.00 SMPS.

Ran some numbers?

**Yep. I use:

http://www.soundtechnology.com/ software.

What the hell do you know about being humble?

**Strawman noted. I discuss facts and you discuss personal issues.

You've
been reading Stereophile haven't you?

**Not for quite a few years.

I suppose you used your raging ego as
a reference.

**Strawman noted. See if you can discuss some facts. If you are able. I
won't hold my breath.

Did you see the article about one of those monstrous
turntables that could only put out the lowest lows if one bought the
optional platter bearing heater?

**Nope. Strawman noted.

How about the $700 "mono" cartridges that
have two coils?

**See above.

Crap runs like a river and you seem to eat bowls of it.
You ran some numbers on your SoundBlaster? What the hell.

**Just to show that a properly designed (and very inexpensive) SMPS is not
an unreasonable choice for a high performance audio device.





COS switchers are unreliable because they run the caps at near maximum
rating. Any flaw in the cap and it blows.

**SMPS are less reliable than linear PS. And that is certainly mostly
down
to electrolytic caps.


When one takes into account the hazardous waste generated by computer
type
garbage and the energy and waste generated to make new ones the simple
linear PS may turn out to be more efficient than first thought. In the
winter it helps heat the house.

**The wastefulness of Linear PS is vastly over-stated. Only when
regulation
is required, do SMPS really shine. For an unregulated PS, you can figure
on
around 90% efficiency for a decent linear PS. I'd be far more bothered by
all those wasteful filaments.

If you are so bothered by waste why don't you go find some idiot driving a
polluting pile of crap and tune it up for him?

**Strawman noted.

One junk car wastes hundreds
of times more energy than a few tube filaments. There is also the raw
fuel
going into the atmosphere.


This is my perspective of the issue. Good luck with the NWO. Mark

**And your perspective appears to be substantially in error.


--
Trevor Wilson
www.rageaudio.com.au

And you seem to believe every thing you read. Ran some numbers on your
SoundBlaster. That's really good.

I just ran some numbers on my stereo. Wow, it's kickin' ass. Thanks for
showing me how to use this sound card. I had no idea that it was also a
sound lab.

Rage on, Trevor. You're damned good at it, but you don't seem to know
much
more than the crap you read in brochures.

Worried about those wasteful filaments? Sheeeeat. All you are worried
about is finding a place to kick your next fit. Please go somewhere else,
and take your switcher with you.

Ran some numbers on my soundblaster, what a crock.

**Numerous strawmen noted.


--
Trevor Wilson
www.rageaudio.com.au

"Mark Harriss" wrote in message
...
truegridtz wrote:


I looked at it. Three feet of crap about some weird amp. Is that one of
those chopper amps? Digital has been a lie from day one. It still
doesn't
work right and it probably never will. It sounds butchered and the
distortion figures are exceptionally low. Distortion figures are almost
always skewed bull**** from whoever is trying to sell something. You
might
take the time to notice that they usually pick the most favorable
frequency
to analyze.


Actually it's a class AB amp, if you read the website info about the amp:

http://www.halcro.com/pdf/Stereophil...002_review.pdf

Page four, second paragraph

**'truegridtz' seems incapable of the capacity to read.


--
Trevor Wilson
www.rageaudio.com.au

Ok, you can put the revolver down now, and stop waving it around.

Thanks for stopping me before something terrible happened.


You'll make trev more nervous than he is already after ****ting in the
r.a.t loungeroom.
Take a break.

Whew, that was close. Thanks, Pat

Mark

**Strawman noted. I discuss facts and you discuss personal issues.

No, this is all a cloaked personal issue for you. Why do you get on a tube
newsgroup to ARGUE about your supposed facts. The only fact is that you
want to argue about issues that people here usually don't care much about.
Tube enthusiasts don't want a switcher on their amp.

Also, why does the little TV that sits next to this computer make a whining
noise when this computer is on? Could it be the switcher?

Just as the transformer can be shrunk by increasing its frequency of
operation in a SMPS, so the L of a LC-input supply can be shrunk if
it is switched at high frequency. Switched mode power factor
correction can use a small L switched into the C. Not much point
perhaps with a linear supply because if all the HF mess has to be
cleaned up anyway, you may as well go the whole hog and switch the
whole caboodle.


Don't forget the part of the SMPS that takes the incoming AC
power and makes it into DC ahead of the actual switching
circuit. That's usually just a rectifier and a filter cap.
Makes for horrible distorted current waveforms and
thus bad power factors. My old company Microlinear used
to make a chip that dealt with this issue, but that was
another dept. of the company (I did video related work),
so I don't know how they did it.

"truegridtz" wrote in message
...


**Strawman noted. I discuss facts and you discuss personal issues.

No, this is all a cloaked personal issue for you.

**Nope.

Why do you get on a tube
newsgroup to ARGUE about your supposed facts.

**Read the title of the thread. Now, read my post. You'll note that I
commented on the use of SMPS vs. linear PS. For a tube amp (without
regulation) there is little incentive to use SMPS apart from mass reduction.
THOSE are facts. I additionally stated that if the OP wanted to REALLY show
his concern for the environment, then the best way to do so would be to
ditch tubes, SE and linear amplification. Moving to a switching amplifier
would be the best thing to do to acheive that aim. THOSE are the facts. I
did not editorialise. I merely stated facts. If you wish to dispute those
facts, in the context of this thread, then feel free to do so.

The only fact is that you
want to argue about issues that people here usually don't care much about.

**You'd best talk to Ian Iveson about that. Clearly he IS thinking about
such issues. If you're not, then fine. I am discussing the facts pertaining
to this thread. If you have nothing to add then you can go **** yourself.


Tube enthusiasts don't want a switcher on their amp.

**And again. Read what I wrote, not what you THINK I wrote.


Also, why does the little TV that sits next to this computer make a
whining
noise when this computer is on? Could it be the switcher?

**And again.


--
Trevor Wilson
www.rageaudio.com.au

**Then move to switching amplifiers using MOSFETs. FAR more
efficient.
Your right, of course, sigh. There are some nice looking boards
around.

Figure on around 90% efficiency for such designs. The differences
between linear and SMPS is pitifully tiny, by comparison.

Certainly small.

I doubt many linear PS are anywhere near as efficient as you say
they can be, particularly not if they are C-input. Not many ppl
would use a choke input, unregulated heater supply either. Voltage
dropping resistors between stages are also wastful.

I am toying with the argument that heat is a necessary part of a
valve's operation, so it's not wasted, ahem.

cheers

Ian

"Ian Iveson" wrote in message
...
**Then move to switching amplifiers using MOSFETs. FAR more efficient.
Your right, of course, sigh. There are some nice looking boards around.

**Sure. They sound like crap, however.


Figure on around 90% efficiency for such designs. The differences between
linear and SMPS is pitifully tiny, by comparison.

Certainly small.

I doubt many linear PS are anywhere near as efficient as you say they can
be, particularly not if they are C-input. Not many ppl would use a choke
input, unregulated heater supply either. Voltage dropping resistors
between stages are also wastful.

**Indeed.


I am toying with the argument that heat is a necessary part of a valve's
operation, so it's not wasted, ahem.

**That would be a fatal blind spot, IMO, because that is where the biggest
gains in energy conservation can be obtained.


--
Trevor Wilson
www.rageaudio.com.au

"robert casey" wrote

Don't forget the part of the SMPS that takes the incoming AC
power and makes it into DC ahead of the actual switching
circuit. That's usually just a rectifier and a filter cap.
Makes for horrible distorted current waveforms and
thus bad power factors. My old company Microlinear used
to make a chip that dealt with this issue, but that was
another dept. of the company (I did video related work),
so I don't know how they did it.

Ah, that's where you use the power factor correction. Check out the
Fairchild links, or my explanation. Or think of it like a
rectified-AC-input boost converter charging that first cap.

cheers, Ian

truegridtz wrote:


I looked at it. Three feet of crap about some weird amp. Is that one of
those chopper amps? Digital has been a lie from day one. It still doesn't
work right and it probably never will. It sounds butchered and the
distortion figures are exceptionally low. Distortion figures are almost
always skewed bull**** from whoever is trying to sell something. You might
take the time to notice that they usually pick the most favorable frequency
to analyze.


Actually it's a class AB amp, if you read the website info about the amp:

http://www.halcro.com/pdf/Stereophil...002_review.pdf

Page four, second paragraph

im running a home made mixer preamp
into a 9200 marshall 2/ch power amp
and this mixer runs from a 200watt pc
power supply, i putt dummy loads
on it for it to work properly, but
did not use its output, i used seperate
supply regulater bords tapped from
the secondry of the swicthing transformer
witch has a centre taped 12volt winding
at 8amps, i used 4 1amp -/+12v boards, the audio
earth is not diretly conneted to mains earth.
"Ian Iveson" wrote in message
. ..
Thanks to all who contributed to the last smps thread. This is a
response delayed by a protracted struggle with the siren voices of
anarchism as I fled my first encounter with EU regulations.
Discipline restored, I realise that as a European I can't sustain my
moral leadership of the new world order whilst consuming 120W in
producing an average 2W of music.

The main advantage of SM is efficiency. Although it was primarily
necessitated by considerations of convenience (small, cool, powerful
devices), efficiency for the sake of conservation is increasingly a
concern of social conscience, and hence will continue to creep into
legislation. We could argue that we only represent a squillienth of
world consumption, but this is like a burglar pleading not guilty on
account of not being a murderer. We could argue that our amps are
only 30% efficient anyway, but then the burglar is pleading on the
ground that burglary is nothing compared to the murder he hasn't
been charged with.

Efficiency is also an interesting pursuit for a "hobbyist", as the
"professionals" call us amateurs. After all, there is bugger all to
get excited about in the audio sections of a valve amp. It is also a
practical concern even for valve amps in situations where weight or
heat output is important, such as in a studio or portable rack.

Then there is the power factor issue, also one of social
responsibility. At the time of my original post I was not aware of
the formal definition of power factor where the waveforms are not
simple sine waves (cos phi when they are).

Actually the full definition of power factor includes distortion as
well as phase difference. Hence the "current gulping" habit of
C-input supplies is just as much a part of the power factor as is
the phase lead of the current (er...I think...).

A simple linear supply with LC-input is a cumbersome and expensive
option, has its own design and execution problems, and only
addresses the power factor problem.

Just as the transformer can be shrunk by increasing its frequency of
operation in a SMPS, so the L of a LC-input supply can be shrunk if
it is switched at high frequency. Switched mode power factor
correction can use a small L switched into the C. Not much point
perhaps with a linear supply because if all the HF mess has to be
cleaned up anyway, you may as well go the whole hog and switch the
whole caboodle.

I asked because I had been messing with a forward converter, and
ended up in a shambles. Simulation was hard enough, especially as
inductor models are so problematic in spice, and the combination of
low and high frequencies is tiresome. Easy to get the right voltage,
efficiency and regulation one at a time, but not all at once.
Practical experiments quickly demonstrate further that once you mix
in the parasitics and quirks of real devices, the only way to avoid
total carnage is to copy a standard solution.

The claim that you need to understand switchers in order to design
them is pure bull****. The principles are not hard to grasp, and the
practical problems of layout and specific device behaviour are
largely beyond the grasp of useful understanding. Experience is much
more important, which is one reason I asked. But the really
important thing the "professionals" have over the amateur is
industry intelligence, safety in number, conference, seminar, plump
for a semiconductor and chip set, cling to the application notes and
keep a straight face whilst muddling through with the layout and
inductors.

For the most entertaining intro I have found, check out Fairchild's
guides. You have to register, but they are well-behaved and worth
it. There is a link to a brilliantly mumbled audio-visual on power
factor correction strategies, and a summary of the requirements of
EU legislation (similar will creep everywhere eventually), including
a succinct definition of PF.

http://www.fairchildsemi.com/whats_new/acdc.html

Mostly flyback. I was surprised that the only respondent actually
using SM went for a boost converter. Perhaps I was barking up the
wrong tree with my forward converter attempt...why?

cheers, Ian

In message , Ian Iveson
writes
"robert casey" wrote

Don't forget the part of the SMPS that takes the incoming AC
power and makes it into DC ahead of the actual switching
circuit. That's usually just a rectifier and a filter cap.
Makes for horrible distorted current waveforms and
thus bad power factors. My old company Microlinear used
to make a chip that dealt with this issue, but that was
another dept. of the company (I did video related work),
so I don't know how they did it.

Ah, that's where you use the power factor correction. Check out the
Fairchild links, or my explanation. Or think of it like a
rectified-AC-input boost converter charging that first cap.

cheers, Ian



The PFC boost chip makes clever use of an analogue multiplier to control
the feedback. That's how it manages to take an amount of current from
the full-wave rectified (but unsmoothed) input that is proportional to
the input voltage, even though it is producing a constant dc output
voltage.

I have designed in an L4981 (ST Micro) as the PFC for the input stage of
my 230W SMPSU powering the voice alarm / PA control panels for Terminal
5 at Heathrow.
--
Chris Morriss