[Iain Churches]

There seem to be two schools of thought regarding linear PSUs
in valve tube/amps. Some favour a long chain with high capacitance
electrolytics. Others favour a simple C-L-C pi filter with caps of
47uF or so, saying that a "fast" psu sounds better.

With valve rectifiers, one is limited in the value of the first
electrolytic, but with FW bridges, these limitations no longer apply.

What type of supply do RATs prefer?
Does a "fast" supply sound different/better?
If so, how does this improvement manifest itself?

regards to all.
Iain

[Eeyore]

Iain Churches wrote:

There seem to be two schools of thought regarding linear PSUs

Linear in the context of PSU's means linear regulated.

You mean ac line frequency PSU.

Graham

[[email protected]]

Iain Churches wrote:
There seem to be two schools of thought regarding linear PSUs
in valve tube/amps. Some favour a long chain with high capacitance
electrolytics.

Not sure what a "long chain" is.

Others favour a simple C-L-C pi filter with caps of
47uF or so, saying that a "fast" psu sounds better.

With valve rectifiers, one is limited in the value of the first
electrolytic, but with FW bridges, these limitations no longer apply.

Most circuits (whether they use solid-state FW bridges or tube
rectifiers) with massive electrolytics need some sort of inrush
limiting (often of substantial complexity).

What type of supply do RATs prefer?

Neither of the above: I feel that choke-input filters are best.
Obviously I'm in the minority :-). I favor this design mostly as an
overreaction against the popularity of massive electrolytics.

Does a "fast" supply sound different/better?

I have no idea why you or anyone else would call C-L-C "fast".

Tim.

[Eeyore]

Iain Churches wrote:

There seem to be two schools of thought regarding linear PSUs
in valve tube/amps. Some favour a long chain with high capacitance
electrolytics. Others favour a simple C-L-C pi filter with caps of
47uF or so, saying that a "fast" psu sounds better.

With valve rectifiers, one is limited in the value of the first
electrolytic, but with FW bridges, these limitations no longer apply.

What type of supply do RATs prefer?
Does a "fast" supply sound different/better?
If so, how does this improvement manifest itself?

You can't be thinking about the effect on class AB amplifiers since these are
never run from resistor fed supplies so I assume you must mean pre-amp stages.

Since these draw an essentially constant DC current and the supply cap bypasses
the audio, the only possible difference would be the size of the decoupling cap.

There's simply no 'fast' or 'slow' about it.

Graham

[Iain Churches]

"Eeyore" wrote in message
...


Iain Churches wrote:

There seem to be two schools of thought regarding linear PSUs

Linear in the context of PSU's means linear regulated.


Hi Graham.
I am not talking about regulated supplies, but the kind of supply
C-L-C one commonly uses in a tube power amp. Some people
seem to go for huge amounts of capacitance, C-L-C-L-C-R-C,
while others prefer just a simple C-L-C chain of more modest values,
and talk about the advantages of a "fast supply" I am interested
to know what they mean.

You mean ac line frequency PSU.
OK.

Iain

[Iain Churches]

wrote in message
ups.com...
Iain Churches wrote:
There seem to be two schools of thought regarding linear PSUs
in valve tube/amps. Some favour a long chain with high capacitance
electrolytics.

Not sure what a "long chain" is.

I looked at an amp yesterday (Swedish built C-L-C-L-C-R-C)
100uF-10H-220uF-10H-220uF-8k2-220uF. The phase splitter
and the front end were powered from the last two caps in this chain.

Others favour a simple C-L-C pi filter with caps of
47uF or so, saying that a "fast" psu sounds better.

With valve rectifiers, one is limited in the value of the first
electrolytic, but with FW bridges, these limitations no longer apply.

Most circuits (whether they use solid-state FW bridges or tube
rectifiers) with massive electrolytics need some sort of inrush
limiting (often of substantial complexity).

Yes indeed. The amp I refer to above had a current limiting resistor
which was shorted by a timer relay.

What type of supply do RATs prefer?

Neither of the above: I feel that choke-input filters are best.
Obviously I'm in the minority :-). I favor this design mostly as an
overreaction against the popularity of massive electrolytics.

Does a "fast" supply sound different/better?

I have no idea why you or anyone else would call C-L-C "fast".

That's what I am trying to find out. And how can it sound better
(or even different:-) ?

Iain

[Eeyore]

Iain Churches wrote:

"Eeyore" wrote in message
Iain Churches wrote:

There seem to be two schools of thought regarding linear PSUs

Linear in the context of PSU's means linear regulated.

Hi Graham.
I am not talking about regulated supplies, but the kind of supply
C-L-C one commonly uses in a tube power amp. Some people
seem to go for huge amounts of capacitance, C-L-C-L-C-R-C,
while others prefer just a simple C-L-C chain of more modest values,
and talk about the advantages of a "fast supply" I am interested
to know what they mean.

I see.

The only conceivable reason I can think of for a 'long chain' is that it may
help filter supply ripple.

I assume then that you do mean the effect on a class AB amplifier ?

Only the *total amount* of series inductance is likely to affect psu sag which
is the only thing I can imagine sounding 'fast' or 'slow' but I suspect ppl
talking about such things are speaking out of their bottoms actually.

I also wouldn't be surprised if they're not comparing entirely similar things
too. Resistive losses in the transformer for example are somewhat more
significant.

Graham

[[email protected]]

Iain Churches wrote:
I have no idea why you or anyone else would call C-L-C "fast".

That's what I am trying to find out. And how can it sound better
(or even different:-) ?

Putting a large capacitor at the end of the chain will hold substantial
charge to handle transient load demands with little droop. Some might
call that "fast".

But the values used in some hobbyist designs are ridiculously huge
(e.g. the 220 uF you cited, and some amps are using 5 times that much
capacitance).

A push-pull tube amp in class AB1 that at idle draws, say, 80mA from a
B+ of 400V will have a dynamic resistance that varies from 5K at idle
to maybe 2K at extreme peaks (where the average current might approach
200mA). But in a RC circuit with 220uF, that 5K has a time constant of
an entire second. That's complete and total overkill. I realize that
complete and utter overkill is often a design goal of hobbyist amps,
but that's ridiculous.

To make things even more ridiculous, some completely class A amps have
massively huge filter capacitors too.

IMHO a few tens of uF (so 22 or 33 or 47 uF) is more than enough.

All that said, I'm obviously in the minority, and everyone who puts in
those humongous capacitors and the necessary inrush limiting circuitry
will pooh-pooh me.

Tim.

[[email protected]]

Iain Churches wrote:
Does a "fast" supply sound different/better?

As a different definition of "fast" that might actually match your
terminology:

With a filter capacitance of 33uF or so, the amplifier stops amplifying
after a fraction
of a second if you remove AC power. That might be "fast".

With a filter capacitance of many hundreds of uF, even after AC power
is removed the filter caps hold enough power to keep B+ on the amp for
many seconds. For a typical push-pull amp, 470uF will keep the
amplifier running for 5 seconds or more. Some of the utterly ridiculous
designs have thousands of uF will keep the amplifier running until the
filaments cool off. That might be "not fast".

Tim.

[Bob H.]

Iain Churches wrote:
There seem to be two schools of thought regarding linear PSUs
in valve tube/amps. Some favour a long chain with high capacitance
electrolytics. Others favour a simple C-L-C pi filter with caps of
47uF or so, saying that a "fast" psu sounds better.

With valve rectifiers, one is limited in the value of the first
electrolytic, but with FW bridges, these limitations no longer apply.

What type of supply do RATs prefer?
Does a "fast" supply sound different/better?
If so, how does this improvement manifest itself?

regards to all.
Iain

I think you're referring to when ps's are built with the least
obstruction between rectifier and output tubes. This might be done by
getting high quality chokes which have the usual 10 or so hy
inductance, but have very low dc resistance, The first choke may be a
swing choke to maximize filtering. Also, just enough filter
capacitance is used to reduce hum to personally acceptable levels and
still offer good bass performance. Using oil or fim caps might be
thought help with quick charge/discharge, low AC impedance and low
current leakage.

I have no hard data nor the desire to accumulate any. this is just a
"food for thought" post.

Hope this helps.

Bob Hedberg

[Ian Iveson]

Linear in the context of PSU's means linear regulated.

But if Linear = Linear Regulated, then Regulated = 0

I understood exactly what Iain meant. It is common to use "linear" as
distinct from "switching".

cheers, Ian

[22/7]

wrote:
But the values used in some hobbyist designs are ridiculously huge
(e.g. the 220 uF you cited, and some amps are using 5 times that much
capacitance).

Not only hobbyist, but also professional designer. The VTL designer
said he put some "ridiculously huge" capacitors in his power amp (I
think he cited the value in joules since charge stored is a function of
both capacitance and voltage across it, though the unit of charge is
coulomb) and it's a salient feature of his design.

P. I.

[[email protected]]

22/7 wrote:
wrote:
But the values used in some hobbyist designs are ridiculously huge
(e.g. the 220 uF you cited, and some amps are using 5 times that much
capacitance).

Not only hobbyist, but also professional designer. The VTL designer
said he put some "ridiculously huge" capacitors in his power amp (I
think he cited the value in joules since charge stored is a function of
both capacitance and voltage across it, though the unit of charge is
coulomb) and it's a salient feature of his design.

The VTL web page says " 200 Joules", which would end up being most of
1000uF at a 700 or 800V B+.

Interesting that both he and I call it "ridiculously huge" but he
thinks it's necessary and I think it's a waste :-).

I've played with the filter caps in my tube amps and find that I cannot
hear the difference by going to anything bigger than 22uF (although I
typically overkill just a little bit by going to 33uF or 47uF). I
tried some 330uF's in parallel and other than the pops I got by blowing
fuses (until I got the power-on sequencing right) I heard nothing
different.

Tim.

[Iain Churches]

"Ian Iveson" wrote in message
. uk...
Linear in the context of PSU's means linear regulated.

But if Linear = Linear Regulated, then Regulated = 0

I understood exactly what Iain meant. It is common to use "linear" as
distinct from "switching".

cheers, Ian


Thanks for the clarification Ian. I wondered if I had used
the term in the wrong context. But it seems not.

On checking some textbooks, I see that type of
psu in an amp to which I refer is indeed referred to as "linear"

Regards to all
Iain

[Eeyore]

Iain Churches wrote:

"Ian Iveson" wrote in message
I said:
Linear in the context of PSU's means linear regulated.

But if Linear = Linear Regulated, then Regulated = 0

No.

The other type is swiching regulated.


I understood exactly what Iain meant. It is common to use "linear" as
distinct from "switching".

cheers, Ian


Thanks for the clarification Ian. I wondered if I had used
the term in the wrong context. But it seems not.

On checking some textbooks, I see that type of
psu in an amp to which I refer is indeed referred to as "linear"

As opposed to switching but the fact of the matter is that's there's nothing
very linear in this kind of psu.

Graham

[Andy Evans]

Speaking just in terms of building several PSUs and listening to them
all, I favour chokes and caps up to 47uF, as has been said by others.
Both polypropylene caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear much difference if
I put a physically small 47uF electrolytic right after the rectifier
(damper diodes in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just can't see why anybody
would use electrolytics in place of polypropylenes - motor run caps are
cheap enough. The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or fast - I have some
to play with so will be trying them out. Any comments on glow tubes?

[Eeyore]

Andy Evans wrote:

Speaking just in terms of building several PSUs and listening to them
all, I favour chokes and caps up to 47uF, as has been said by others.
Both polypropylene caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear much difference if
I put a physically small 47uF electrolytic right after the rectifier
(damper diodes in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just can't see why anybody
would use electrolytics in place of polypropylenes - motor run caps are
cheap enough. The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or fast - I have some
to play with so will be trying them out. Any comments on glow tubes?

As ever you are the ultimate audiophool.

You do however confirm my suspicions about what these clowns call slow and fast.

That huge mallory cap woud actually provide a 'firmer' more technically accurate
power supply with less sag on transients but it seems the 'phools actually
*like* their supplies to sag on load. Just as they *like* lots of distortion
too.

The effect is known in transistor amps too.

Graham

[Phil Allison]

"Ian Iveson Pommy ****head

Linear in the context of PSU's means linear regulated.

But if Linear = Linear Regulated, then Regulated = 0


** Purest gobbledegook.


I understood exactly what Iain meant.


** Must be a Babel Fish.


It is common to use "linear" as distinct from "switching".


** It is an error to do so if the supply is not regulated, on the grounds
that ambiguity is error.

Plus - there is nothing very " linear " about what happens when an AC
supply is rectified and filtered by electros to get DC. Such supplies are
mostly called "conventional" when there is a need to distinguish them from
the switchmode kind.

There are switching supplies that deliver unregulated AC - ie for halogen
lighting.

There are conventional supplies that have switching regulators hanging off
them.

What you call them in writing DEPENDS ON CONTEXT.




........ Phil

[Bob H.]

Andy Evans wrote:
Speaking just in terms of building several PSUs and listening to them
all, I favour chokes and caps up to 47uF, as has been said by others.
Both polypropylene caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear much difference if
I put a physically small 47uF electrolytic right after the rectifier
(damper diodes in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just can't see why anybody
would use electrolytics in place of polypropylenes - motor run caps are
cheap enough. The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!


I find that a smallish cap, like 10 uf before the first choke sounds
nice, and provides decent additional ripple control, while pulling b+
up a tad. I prefer choke input, but a wee bit up there helps out a lot
in my experience. Some like to put 1or 2 uf up there, but I didn't
notice much of a change anywhere else with that. To each their own.

Also, I've found that ASC polyprop in veg oil are nice filter caps, if
the room is available.

regards,
Bob H.

[Iain Churches]

"Bob H." wrote in message
ups.com...

I find that a smallish cap, like 10 uf before the first choke sounds
nice,

Hi Bob,

Now we are getting to the crux of the question:-))
Does is sound *different* to a long string of high
capacitance electrolytics?

Iain

[Iain Churches]

"Eeyore" wrote in message
...


Andy Evans wrote:

Speaking just in terms of building several PSUs and listening to them
all, I favour chokes and caps up to 47uF, as has been said by others.
Both polypropylene caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear much difference if
I put a physically small 47uF electrolytic right after the rectifier
(damper diodes in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just can't see why anybody
would use electrolytics in place of polypropylenes - motor run caps are
cheap enough. The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or fast - I have some
to play with so will be trying them out. Any comments on glow tubes?

As ever you are the ultimate audiophool.

You do however confirm my suspicions about what these clowns call slow and
fast.

So are you saying Graham, that a by "fast" people mean electrolytics of
lowish
values that charge and discharge quickly, and allow the B+ to sag when the
demand
on the rail is high.

If so, I am interested to know how this can "sound" and better. But,
perhaps,
knowing your views, you may not be the best person to ask about this:-))

That huge mallory cap woud actually provide a 'firmer' more technically
accurate
power supply with less sag on transients but it seems the 'phools actually
*like* their supplies to sag on load. Just as they *like* lots of
distortion
too.

No. I think you are making an incorrect assumption there. The Swedish built
amp I looked at earler this week proved to have only minimal sag on the B+
when pulse tested in 1 sec burst at full power. Most people go for stiff
supplies
with low impedance.

But, to ask the question again, I am still interested to know how a more
modest "fast" supply can sound different/better.

Iain

[Eeyore]

Iain Churches wrote:

"Eeyore" wrote in message
Andy Evans wrote:

Speaking just in terms of building several PSUs and listening to them
all, I favour chokes and caps up to 47uF, as has been said by others.
Both polypropylene caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear much difference if
I put a physically small 47uF electrolytic right after the rectifier
(damper diodes in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just can't see why anybody
would use electrolytics in place of polypropylenes - motor run caps are
cheap enough. The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or fast - I have some
to play with so will be trying them out. Any comments on glow tubes?

As ever you are the ultimate audiophool.

You do however confirm my suspicions about what these clowns call slow and
fast.

So are you saying Graham, that a by "fast" people mean electrolytics of
lowish
values that charge and discharge quickly, and allow the B+ to sag when the
demand on the rail is high.

I wasn't really sure originally when you posted your question since I don't use
such adjectives to describe audio myself but I had my suspicions which Evans
appears to have confirmed.


If so, I am interested to know how this can "sound" and better. But,
perhaps,
knowing your views, you may not be the best person to ask about this:-))

LOL ! Don't fret over that.


That huge mallory cap woud actually provide a 'firmer' more technically
accurate
power supply with less sag on transients but it seems the 'phools actually
*like* their supplies to sag on load. Just as they *like* lots of
distortion too.

No. I think you are making an incorrect assumption there. The Swedish built
amp I looked at earler this week proved to have only minimal sag on the B+
when pulse tested in 1 sec burst at full power. Most people go for stiff
supplies with low impedance.

There's more than just the cap size though. The 'regulation' of the transformer
comes into play lots too. So there's more to this than caps and chokes.


But, to ask the question again, I am still interested to know how a more
modest "fast" supply can sound different/better.

It results in greater short term dynamic headroom. It is so short term though
that it's value is questionable.

Graham

[Andy Evans]

That huge mallory cap woud actually provide a 'firmer' more technically
accurate
power supply with less sag on transients but it seems the 'phools
actually
*like* their supplies to sag on load. Just as they *like* lots of
distortion
too.

You may know something about theory but that often appears to be all
you know. As usual you are prepared to completely ignore how componants
SOUND, and worse than that you seem to elevate yourself onto some kind
of pedestal as if your knowledge of theory replaces anyone elses
information about how their equipment - which of course you've never
listened to but don't let a small thing like that stop you in mid
flight - works and sounds. You're a well-known armchair theorist and
all I can say to you is you are completely out of touch with the actual
sounds of the stuff you pretend to be an expert on. Maybe sound doesn't
matter to you?

[Andy Evans]

Now we are getting to the crux of the question:-))
Does is sound *different* to a long string of high
capacitance electrolytics?

Iain

If you want a description of the difference in sound terms between low
value polypropylenes and bigger electrolytics, I'd say they were more
vivid and immediate - I guess that's something like "faster". The
Mallories I tried were without doubt slower sounding, and they were
physically big too. Back when I was trying out dozens of caps in my
power supplies to see if I could hear the difference, it did seem to me
that if you had to use electrolytics then physically small ones seemed
on the face of it slightly better sounding, and an engineer friend said
he'd found the same. Over on Audio Asylum you'll find a large group of
builders who use only polypropylenes, preferably in oil, in their PSUs.
All my own experience is with balanced push pull amps, so you may have
different results in SE.

[Eeyore]

Andy Evans wrote:

Now we are getting to the crux of the question:-))
Does is sound *different* to a long string of high
capacitance electrolytics?

Iain

If you want a description of the difference in sound terms between low
value polypropylenes and bigger electrolytics, I'd say they were more
vivid and immediate - I guess that's something like "faster". The
Mallories I tried were without doubt slower sounding, and they were
physically big too. Back when I was trying out dozens of caps in my
power supplies to see if I could hear the difference, it did seem to me
that if you had to use electrolytics then physically small ones seemed
on the face of it slightly better sounding, and an engineer friend said
he'd found the same. Over on Audio Asylum you'll find a large group of
builders who use only polypropylenes, preferably in oil, in their PSUs.
All my own experience is with balanced push pull amps, so you may have
different results in SE.

But were these caps assembled by naked virgins at midnight under a full moon ?

Sure, if you make your power supply sloppy I'm sure it affects the sound.

Since the typical toob nut appears to revel in added distortions, I have no
doubt that worse in better in your febrile imagination.

Graham

[Eeyore]

Andy Evans wrote:

That huge mallory cap woud actually provide a 'firmer' more technically
accurate
power supply with less sag on transients but it seems the 'phools
actually
*like* their supplies to sag on load. Just as they *like* lots of
distortion too.

You may know something about theory

I know *lots* of design theory and practice too.


but that often appears to be all
you know. As usual you are prepared to completely ignore how componants
SOUND,

Passive components very rarely have any 'sound' actually. It's very much the
exception rather than the rule.


and worse than that you seem to elevate yourself onto some kind
of pedestal as if your knowledge of theory replaces anyone elses
information about how their equipment

My level of knowledge is *very* comprehensive. It's based on a heck of a lot of
experience too.


- which of course you've never
listened to but don't let a small thing like that stop you in mid
flight - works and sounds. You're a well-known armchair theorist and
all I can say to you is you are completely out of touch with the actual
sounds of the stuff you pretend to be an expert on. Maybe sound doesn't
matter to you?

I'm certainly no armchair theorist. I design audio for a living. Do you ?

Furthermore I view all your voodoo mumbo-jumbo about magic components and the
like as being a bit like little kids playing with things they don't understand
and wrongly attributing effects to what they've been told by the snake oil
merchants to believe.


Graham

[Ian Iveson]

Beautiful Phil wrote:

Linear in the context of PSU's means linear regulated.

But if Linear = Linear Regulated, then Regulated = 0

** Purest gobbledegook.

Quite. Thanks. A simple and logical reduction to absurdity. Perhaps he
meant to say "Linear...means regulated."?

It is common to use "linear" as distinct from "switching".


** It is an error to do so if the supply is not regulated, on the
grounds that ambiguity is error.

But there is already a good word for "regulated". We generally say
"regulated".

Plus - there is nothing very " linear " about what happens when an
AC supply is rectified and filtered by electros to get DC. Such
supplies are mostly called "conventional" when there is a need to
distinguish them from the switchmode kind.

Rubbish. Conventions change. How about a conventional switcher?

Just searched several suppliers for "Linear unregulated power supply".
Plenty hits. Try. Learn. Also try searching for "Conventional power
supply".

Linear is pretty meaningless word to use for a power supply anyway,
IMO. But it is the word generally used for non-switchers. That's why I
would bet that *everyone* knew what Iain meant. Even you.

What you call them in writing DEPENDS ON CONTEXT.

As with all things.

Ian

[Iain Churches]

"Andy Evans" wrote in message
oups.com...
Now we are getting to the crux of the question:-))
Does is sound *different* to a long string of high
capacitance electrolytics?

Iain

If you want a description of the difference in sound terms between low
value polypropylenes and bigger electrolytics, I'd say they were more
vivid and immediate - I guess that's something like "faster". The
Mallories I tried were without doubt slower sounding, and they were
physically big too. Back when I was trying out dozens of caps in my
power supplies to see if I could hear the difference, it did seem to me
that if you had to use electrolytics then physically small ones seemed
on the face of it slightly better sounding, and an engineer friend said
he'd found the same. Over on Audio Asylum you'll find a large group of
builders who use only polypropylenes, preferably in oil, in their PSUs.
All my own experience is with balanced push pull amps, so you may have
different results in SE.

Thanks Andy. That's interesting. The sort of info I was looking for.
I am currently working on a 50W PP amp.

Iain

[Iain Churches]

"Eeyore" wrote in message
...
Graham replied to Andy:

But were these caps assembled by naked virgins at midnight under a full
moon ?
Sure, if you make your power supply sloppy I'm sure it affects the sound.

It is in the interests of no-one to build a sloppy psu. I notice that most
amps from the 60s had fairly modest supplies,. and quite often the output
pair in a pp amp were supplied straight from the reservoir cap, which was
often 47uF to enable the use of a smaller choke downstream to supply the
phase inverter and front end.

But in those days, large electrolytics were scarce and expensive. Now
they are plentiful and not-too-costly, so it seems to make sense to
use a stiffer supply.

Graham knocks Andy again:
Since the typical toob nut appears to revel in added distortions, I have
no
doubt that worse in better in your febrile imagination.

That's a pretty unfair appraisal, Graham. Do you really think that? If so,
why are you waisting your time oin a tube forum:-) ?? In the end, it all
comes down to reproducing music. Many people feel that a valve/tube
amp give a more musical performance (for whatever reason) This is why
tube amps are so popular. This seems to bother you.

Regards to all
Iain

[Iain Churches]

"Eeyore" wrote in message
...


Iain Churches wrote:

"Eeyore" wrote in message
Andy Evans wrote:

Speaking just in terms of building several PSUs and listening to them
all, I favour chokes and caps up to 47uF, as has been said by others.
Both polypropylene caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear much difference
if
I put a physically small 47uF electrolytic right after the rectifier
(damper diodes in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just can't see why
anybody
would use electrolytics in place of polypropylenes - motor run caps
are
cheap enough. The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or fast - I have some
to play with so will be trying them out. Any comments on glow tubes?

As ever you are the ultimate audiophool.

You do however confirm my suspicions about what these clowns call slow
and
fast.

So are you saying Graham, that a by "fast" people mean electrolytics of
lowish
values that charge and discharge quickly, and allow the B+ to sag when
the
demand on the rail is high.

I wasn't really sure originally when you posted your question since I
don't use
such adjectives to describe audio myself but I had my suspicions which
Evans
appears to have confirmed.

Yes. Understood. But other people do use these adjectives,
and widely. I wanted to find out how a "fast"
supply, (which I take to mean a C-L-C chain with caps of modest
capacitance) can have an effect upon the sound of an amplifier.
I can appreciate the benefit of a supply with high capacitance
and hence low impedance


If so, I am interested to know how this can "sound" and better. But,
perhaps,
knowing your views, you may not be the best person to ask about this:-))

LOL ! Don't fret over that.

OK. Any further light you can cast on the matter would be
appreciated.

best regards
Iain

[Eeyore]

Iain Churches wrote:

"Andy Evans" wrote in message
oups.com...
Now we are getting to the crux of the question:-))
Does is sound *different* to a long string of high
capacitance electrolytics?

Iain

If you want a description of the difference in sound terms between low
value polypropylenes and bigger electrolytics, I'd say they were more
vivid and immediate - I guess that's something like "faster". The
Mallories I tried were without doubt slower sounding, and they were
physically big too. Back when I was trying out dozens of caps in my
power supplies to see if I could hear the difference, it did seem to me
that if you had to use electrolytics then physically small ones seemed
on the face of it slightly better sounding, and an engineer friend said
he'd found the same. Over on Audio Asylum you'll find a large group of
builders who use only polypropylenes, preferably in oil, in their PSUs.
All my own experience is with balanced push pull amps, so you may have
different results in SE.

Thanks Andy. That's interesting. The sort of info I was looking for.
I am currently working on a 50W PP amp.

Unfortunately his ideas are plain bonkers.


Graham

[Eeyore]

Iain Churches wrote:

"Eeyore" wrote in message

Graham replied to Andy:

But were these caps assembled by naked virgins at midnight under a full
moon ?
Sure, if you make your power supply sloppy I'm sure it affects the sound.

It is in the interests of no-one to build a sloppy psu. I notice that most
amps from the 60s had fairly modest supplies,. and quite often the output
pair in a pp amp were supplied straight from the reservoir cap, which was
often 47uF to enable the use of a smaller choke downstream to supply the
phase inverter and front end.

When I refer to a PSU being 'sloppy' I mean the load regulation being poor. The
use of small reservoir caps will certainly make a supply 'sloppier' and will
undoubtedly affect an amplifier's dynamic perfroamnce. I recall the effect first
being noted wrt Bob Carver's designs notably the Phase Linear transistor
amplifiers.


But in those days, large electrolytics were scarce and expensive.

True.


Now
they are plentiful and not-too-costly, so it seems to make sense to
use a stiffer supply.

This is what I tend to do, but I also don't believe in 'going over the top' with
it !


Graham knocks Andy again:
Since the typical toob nut appears to revel in added distortions, I have
no doubt that worse in better in your febrile imagination.

That's a pretty unfair appraisal, Graham. Do you really think that?

It's clear from what I've heard here that those who like tubes are indeed
captivated by their added distortions. I could elaborate at great length.


If so, why are you waisting your time oin a tube forum:-) ??

I don't consider it wasted time, it's been quite an education actually and also
because I wanted to find out for myself what all the fuss was about. I
additionally have a decent working knowledge of this area of electronics.


In the end, it all
comes down to reproducing music. Many people feel that a valve/tube
amp give a more musical performance (for whatever reason) This is why
tube amps are so popular. This seems to bother you.

Not for one moment.

It does bother me that some ppl see *their* idea of amplification to be superior
based on nothing more than something like religious fervour though and totally (
apparently ) to the contradiction of the scientific method.

Graham

[Arny Krueger]

"Eeyore" wrote in
message
Iain Churches wrote:

"Eeyore" wrote
in message
Andy Evans wrote:

Speaking just in terms of building several PSUs and
listening to them all, I favour chokes and caps up to
47uF, as has been said by others. Both polypropylene
caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear
much difference if I put a physically small 47uF
electrolytic right after the rectifier (damper diodes
in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just
can't see why anybody would use electrolytics in place
of polypropylenes - motor run caps are cheap enough.
The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or
fast - I have some to play with so will be trying them
out. Any comments on glow tubes?

As ever you are the ultimate audiophool.

You do however confirm my suspicions about what these
clowns call slow and fast.

So are you saying Graham, that a by "fast" people mean
electrolytics of lowish
values that charge and discharge quickly, and allow the
B+ to sag when the demand on the rail is high.

I wasn't really sure originally when you posted your
question since I don't use such adjectives to describe
audio myself but I had my suspicions which Evans appears
to have confirmed.


If so, I am interested to know how this can "sound" and
better. But, perhaps,
knowing your views, you may not be the best person to
ask about this:-))

LOL ! Don't fret over that.


That huge mallory cap woud actually provide a 'firmer'
more technically accurate
power supply with less sag on transients but it seems
the 'phools actually *like* their supplies to sag on
load. Just as they *like* lots of distortion too.

No. I think you are making an incorrect assumption
there. The Swedish built amp I looked at earler this
week proved to have only minimal sag on the B+ when
pulse tested in 1 sec burst at full power. Most people
go for stiff supplies with low impedance.

There's more than just the cap size though. The
'regulation' of the transformer comes into play lots too.
So there's more to this than caps and chokes.


But, to ask the question again, I am still interested to
know how a more modest "fast" supply can sound
different/better.

It results in greater short term dynamic headroom. It is
so short term though that it's value is questionable.

In my eyes the whole issue begs for some impartial listening tests.

The so-called "fast" power supply looks like a passive analog
lumped-parameter L-C delay line to me.

I sense that I'm in the presence of a bunch of know-nothings who like to
solder up weird collections of parts and declare themselves kings of the
audio world.

[Eeyore]

Iain Churches wrote:

"Eeyore" wrote in message
Iain Churches wrote:

So are you saying Graham, that a by "fast" people mean electrolytics of
lowish
values that charge and discharge quickly, and allow the B+ to sag when
the
demand on the rail is high.

I wasn't really sure originally when you posted your question since I
don't use
such adjectives to describe audio myself but I had my suspicions which
Evans appears to have confirmed.

Yes. Understood. But other people do use these adjectives,
and widely.

To me, it seems to be a modern fad to use these terms used mainly by ppl who
have dropped even any pretence of taking an interest in scientific analysis.


I wanted to find out how a "fast"
supply, (which I take to mean a C-L-C chain with caps of modest
capacitance) can have an effect upon the sound of an amplifier.
I can appreciate the benefit of a supply with high capacitance
and hence low impedance

It's important to note that supply does appear in the signal path, although the
extent to which it does varies with amplifier topology.

So a supply cap's influence will appear somewhere in the output. The smaller the
cap, the greater its influence will be ( assuming it has an audible one ).

A smaller PSU cap will ultimately affect the LF response too btw. I'll bet the
capacitor nuts forget this ( probably never even thought of it more like ).


If so, I am interested to know how this can "sound" and better. But,
perhaps,
knowing your views, you may not be the best person to ask about this:-))

LOL ! Don't fret over that.

OK. Any further light you can cast on the matter would be
appreciated.

You're welcome.

Graham

[Eeyore]

Arny Krueger wrote:

"Eeyore" wrote
Iain Churches wrote:
"Eeyore" wrote
Andy Evans wrote:

Speaking just in terms of building several PSUs and
listening to them all, I favour chokes and caps up to
47uF, as has been said by others. Both polypropylene
caps and chokes audibly improve the sound over
electrolytics, the exception being that I can't hear
much difference if I put a physically small 47uF
electrolytic right after the rectifier (damper diodes
in my case), then follow that with polypropylenes. As
long as you have the room in your chassis, I just
can't see why anybody would use electrolytics in place
of polypropylenes - motor run caps are cheap enough.
The worst caps I ever used in a PSU were huge Mallory
computer grade electrolytics. Slow and dead - yuk!

I don't know whether glow tubes qualify as slow or
fast - I have some to play with so will be trying them
out. Any comments on glow tubes?

As ever you are the ultimate audiophool.

You do however confirm my suspicions about what these
clowns call slow and fast.

So are you saying Graham, that a by "fast" people mean
electrolytics of lowish
values that charge and discharge quickly, and allow the
B+ to sag when the demand on the rail is high.

I wasn't really sure originally when you posted your
question since I don't use such adjectives to describe
audio myself but I had my suspicions which Evans appears
to have confirmed.


If so, I am interested to know how this can "sound" and
better. But, perhaps,
knowing your views, you may not be the best person to
ask about this:-))

LOL ! Don't fret over that.


That huge mallory cap woud actually provide a 'firmer'
more technically accurate
power supply with less sag on transients but it seems
the 'phools actually *like* their supplies to sag on
load. Just as they *like* lots of distortion too.

No. I think you are making an incorrect assumption
there. The Swedish built amp I looked at earler this
week proved to have only minimal sag on the B+ when
pulse tested in 1 sec burst at full power. Most people
go for stiff supplies with low impedance.

There's more than just the cap size though. The
'regulation' of the transformer comes into play lots too.
So there's more to this than caps and chokes.


But, to ask the question again, I am still interested to
know how a more modest "fast" supply can sound
different/better.

It results in greater short term dynamic headroom. It is
so short term though that it's value is questionable.

In my eyes the whole issue begs for some impartial listening tests.

The so-called "fast" power supply looks like a passive analog
lumped-parameter L-C delay line to me.

I sense that I'm in the presence of a bunch of know-nothings who like to
solder up weird collections of parts and declare themselves kings of the
audio world.

This is very much the impression I get too.

Their voodoo seems to keep them happy though. It makes a change from belief in
magic cables.

Graham

[Arny Krueger]

"Iain Churches" wrote in message

"Eeyore" wrote
in message ...
Graham replied to Andy:

But were these caps assembled by naked virgins at
midnight under a full moon ?
Sure, if you make your power supply sloppy I'm sure it
affects the sound.

It is in the interests of no-one to build a sloppy psu. I
notice that most amps from the 60s had fairly modest
supplies,. and quite often the output pair in a pp amp
were supplied straight from the reservoir cap, which was
often 47uF to enable the use of a smaller choke
downstream to supply the phase inverter and front end.

The small resevoir caps of that age had a lot to do with the limited
capacitor technology of the days, and cost considerations.

But in those days, large electrolytics were scarce and
expensive.

Agreed, but you left out "big". In the declining days of tubes, there were
interesting devices such as the Paoli 60M which did use pretty large-value
electrolytics in their power supplies. Computer technology was coming to the
rescue of audio.

Now they are plentiful and not-too-costly, so it seems to
make sense to use a stiffer supply.

At least until diminishing returns sets in.

Graham knocks Andy again:
Since the typical toob nut appears to revel in added
distortions, I have no
doubt that worse in better in your febrile imagination.

Truth hurts?

That's a pretty unfair appraisal, Graham. Do you really
think that?

Lots of people think that. Can we all say SET?

If so, why are you waisting your time oin a
tube forum:-) ??

waisting? Is that a fat joke? ;-)

In the end, it all comes down to reproducing music.

Well, if you want accurate reproduction, what are you doing with tubes?

Many people feel that a valve/tube amp give a more musical performance
(for whatever reason)

I agree that tubed amplifiers seem to tend towards being musical
instruments, in the sense that a violin makes sounds that are vastly
different from its input.

This is why tube amps are so popular.

...mostly among guitar players, and even that is going away.

This seems to bother you.

No, its just a little strange.

[Andre Jute]

Iain Churches wrote:

There seem to be two schools of thought regarding linear PSUs
in valve tube/amps. Some favour a long chain with high capacitance
electrolytics. Others favour a simple C-L-C pi filter with caps of
47uF or so, saying that a "fast" psu sounds better.

With valve rectifiers, one is limited in the value of the first
electrolytic, but with FW bridges, these limitations no longer apply.

What type of supply do RATs prefer?
Does a "fast" supply sound different/better?
If so, how does this improvement manifest itself?

regards to all.
Iain

Iain:

A fast power supply is shorthand to describe a particular sound. It is
a psycho-acoustic reference to an electronic implementation that should
be thought of as balance on the ear and in the circuit.

To understand what it is about and how it came about, you need to
return to the roots of tube hi-fi. The idea of the high fidelity power
supply after WWII and until the general arrival of the transistor and
for perhaps a decade afterwards, was to reduce supply rail noise to
30dB under the fundamental. Common rule of thumb shortcuts were in use
to achieve this purpose.

First they would calculate the choke size. In choke input filters
inductance in Henries was required to be at least:

L = Voltage/(Current x 940) for 50Hz supplies (Europe)

L = Voltage/(Current x 1130) for 60Hz supplies (US)

Now they could calculate the cap size:

C = 56/L

This is on the assumption that they would use two choke sections, LCLC,
in a choke input filter. The input cap in a pi filter, CLC, would be
the same as the second cap. All filtering sections of the same values
offers the greatest efficiency.

Now, what they would actually calculate, taking the example of a
monoblock Class A SE300B, would be a cap of around 5 to 6uF and a choke
of about the same in Henries.

In days of yore caps were expensive and anyway many of the preferred
rectifiers had ludicrously low capacitance limits. But iron was cheap.
So the choke was bumped up a lot, often to 20 or 30H (vide Williamson),
and the caps were bumped up a little, to say 6-8uF, the 8uF for really
daring hobbyists. High voltage oil caps were common in the very best
equipment; they do have a distinct sound.

Today we adjust the balance the other way because our iron is expensive
and our caps not quite so expensive. Furthermore, today's preferred
rectifiers (generally slow-start types or milspec ultra-HV types) can
handle up to 60uF as the first cap in pi filter. So, whatever we
calculated above, we would usually fit a 10H choke (or chokes) in
conjunction with the conveniently available 47uF caps. Andy Evans wrote
the other day that 40uF motor run polyprops are plenty; he was
absolutely right. The best sounding 845 I ever built had only 20uF in
each capacitance leg (made by stacking 630V polys, and only two legs,
i.e. 40uF altogether.

Between the two paragraphs immediately above about forty years passed.
The two generations of DIYers before us had an umbilical connection to
the ARRL; they were radio hams, engineers, techies, very knowledgeable
amateurs, hard workers of courtesy in their manner and modesty in their
opinions. They subscribed to another precept that most of today's
"audiophiles" can relearn with profit. Though they didn't call it that,
the took a systems approach to their hi-fi. It was expressed as a
balanced system, with each component balanced to the rest, and each
component internally at peace with its own balance. They would never
build an amp, for instance, with excessive reach into one of the
frequency extremes. "Excessive" here means not only odd, over the top,
but out of balance with the other frequency extreme. An amp capable of
a clean 100Hz, actually rather good in the day, should not reach past 8
or 10KHz at the other extreme or it will sound skewed. They aspired to
perhaps 60Hz-15KHz.

Today we thoughtlessly accept as axiomatic the wretchedly inaccurate
statement, devised by bureaucrats for the convenience of lowest common
denominator engineers and jumped-up techies, that the human audio range
is 20Hz to 20KHz, and furthermore we don't swat down those idiots who
claim all speakers should go down to 20Hz just because any old fool can
make a solid state amp produce some kind of 20Hz noise (and it isn't so
difficult in tubes either, though tubies are generally a bit smarter).
These two facts between them account for a lot of truly wretched sound
produced at vast expense. That position can only become worse when the
same morons will assure us that, because the new media can go up to
35KHZ, we should follow the techies up there. No one asks the
devastating question, Why?

Now, one of the ways in which the axiomatic audio band (as distinct
from the real audiophile audio band, what people actually listen to,
what will not interfere with their enjoyment) wrecks the sound of a
system is by unbalancing the sound. To get rock-steady bass at 20Hz,
the amp must be capped up almost as if for DC operation; the common
1.6Hz is an economy compromise (!). The sound is subtly unbalanced.
Very few people can identify the cause instantly but there is a sense
of vague unease.

That sense of vague unease goes away the moment people hear a tube amp,
especially a tube amp with a tube rectifier, on which a more balanced
approach in the disposition of energy storage is almost forced by the
tube rectifier's limitations, with the automatic consequence that the
amp's bandwidth (and possibly its slewing behaviour) is balanced
internally--and externally on the ear because the amp is now also more
in tune with the speakers it drives. Alternatively, when you listen to
one of those American banksa6550 amps, you instantly recover the
psychic unease for the good and simple reason that you're listening to
a pseudo-silicon amp, capped up to the "audio band" in the power supply
and in the signal caps -- and then several multiples beyond reason. As
an aside, regulated anything makes the unease worse.

The point about the speakers is important. There aren't any speakers
except huge custom horns which make a clean ("natural") 20Hz sound.
There aren't any people who can hear over 22kHz (which is where Lowther
horns will go); most people, including almost everyone who can afford
really good hi-fi, cannot hear over 12-14KHz. If the amp is grotesquely
out of sympathy with the speaker, and by definition an amp capped up to
the power of lightning must be out sympathy with any loudspeaker
physics and modern architecture permits us, the frustrated owner isn't
approaching Nirvana more closely, he is adding obstacles in his path to
the Valhalla of a well amp in a well system making a well sound.

Notice that, while I put the argument psycho-acoustically because in
the end that is all that matters, it is perfectly amenable to arguing
on the technical electronics as well.

The description "a fast amp" arose in the early 1990's to describe an
amp which didn't suffer from this dead, unbalanced sound created by
unbalancing the midrange. I believe the actual words (but not the
concept which, as I have demonstrated, was extant all along) came out
of the New York Triode Mafia. As far as I know, Herb Reichert (who was
the American Tango and Audio Note UK agent) could have invented phrase;
he certainly popularized it in his article about his "Blood and
Thunder" 300B design in one of the first four issues of Sound
Practices, which set the tone for the SET/tube revival.

So, the "fast amp" isn't in fact one with 10^umpteen headroom for
current demands (as if we were designing a current amp! -- when will
some people put their minds in gear; tube amps are *voltage*
multipliers (1)) but the sound of a very conservatively designed system
in which the amp is deliberately matched (held back) to the least
controllable parts of the chain, which are the room, the speakers and
the ears of the owner. It isn't really primarily to do with the amount
of capacitance in the power supply but that is an easy assumption to
make because the worst examples of "slow" amps, easy to spot because
they screech (everyone extends the overcapping to the signal caps as
well) while at the same time offering only thumping, one-note, very
stolid, draggingly overhanging bass, and thus are easily fixed by
snipping the wires to some of the caps (after discharging them
thoroughly, of course).

Incidentally, this "fast" sound is also physically balanced, in that it
is very easy to live with speakers that have a symmetrical extension
either side of the midrange, for instance the ESL-63 and the better
Lowther horns like the Fidelio. That is why I say that a speaker which
doesn't have an outstanding midrange cannot be developed into a great
speaker -- a fabulous midrange is the pivot on which all good things
turn.

HTH.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

(1) Technically, one of the ways the "fast amp" achieves its beneficial
effects is by faster response to transient spikes because it isn't
sitting there waiting for humongous computer grade caps to charge up...
Counter-intuitive, I agree, but if you think it through you will come
to the same conclusion. In the middle rank of amps (SE300B say), 10H
and 47uF is a good compromise between a fast "natural" sound on most
music (and the sweetest vocals, which are the greatest beneficiary of
component choices which favour the midrange so heavily) and the ability
to sustain the less frequent symphonic forte. Considering your work,
you might of course take a different view or adjust the capacitance in
your amp on test. On the other hand, if you have two or more amps, why
not optimize an amp for each kind of music? "One amp plays everything"
is another of those dumb bureaucratic rules made for the convenience of
the lowest common denominator of techies.

[Iain Churches]

"Eeyore" wrote in message
...

When I refer to a PSU being 'sloppy' I mean the load regulation being
poor.

So this must include the power transformer also. Some have
considerably better regulation than others (to avoid mis-
interpretation again, by "transformer regulation" I mean the
term in the way that Sowter and Lundahl use it: i.e the
variation in output voltage between no load and full load)

This is what I tend to do, but I also don't believe in 'going over the
top' with
it !

I would be interested to know what you define as
"over the top" As I mentioned before, I have just been listening
to a Swedish built amp with 100uF-10H-200uF-10H-200uF-5k6-200uF.
That seems to me to be a little "over the top" The first choke had a 1A
rating. But it was a "money no object" design by the designer who
demonstrated it to me, for a very discerning client.

It's clear from what I've heard here that those who like tubes are indeed
captivated by their added distortions.

:-)

It is not difficult to cosnstruct a pp 50W tube amp with THD of
0.1% at 1kHz full power and a noise floor of about 150µV (weighted)
I have built several.

http://www.kolumbus.fi/iain.churches...em/C50_002.jpg

At lowish power (enough to fill the average listening room with music)
the THD is 0.03% Do you think that you, or any of the rest of us can
even detect this "added distortion" let alone be captivated by it?

I could elaborate at great length.

Please do. That's what we come here for:-)

I don't consider it wasted time, it's been quite an education actually and
also
because I wanted to find out for myself what all the fuss was about. I
additionally have a decent working knowledge of this area of electronics.

As do most people who build valve amps. The best way to find
out what all the fuss is about is to build one:-)

I live in Scandinavia, and so the situation here might not be parallel to
yours, but here, particularly in the past ten years, there has been a
considerable migration from SS to tube amps, by people who were
not satisfied with what they were hearing. I cannot recall one single
case of someone going the other way:-))

In addition, here, the very top of high end audio is dominated by tube amps
for which there is often a waiting list. In contrast, one can by a Krell
over the counter at a very good discount.

In the end, it all
comes down to reproducing music. Many people feel that a valve/tube
amp give a more musical performance (for whatever reason) This is why
tube amps are so popular. This seems to bother you.

Not for one moment.

It does bother me that some ppl see *their* idea of amplification to be
superior
based on nothing more than something like religious fervour though and
totally (
apparently ) to the contradiction of the scientific method.

:-)) I have never come across this "religious fervour" - a term often used
by the anti tube faction. They also talk about "snob value" etc. I have
never come across this either.

I belong to a "recorded music group" with some thirty members. More
than half of these now have tube amps. These people are not in the least
concerned with snob value or religious fervour, they are simply looking
for the system (amp and speakers) which will reproduce the music to
which they listen in the way which they think it should be reproduced.
It matters not a jot to them if the amp is SS, tube, or powered by North
Sea gas. It's that simple.

regards to all
Iain

[Andy Evans]

high capacitance and hence low impedance

surely low impedence is a quality of the iron - the transformer and
chokes. See Dr Lowmu (Jeff Medwin) in a huge number of AA threads on
the subject.

[Eeyore]

Iain Churches wrote:

"Eeyore" wrote in message

When I refer to a PSU being 'sloppy' I mean the load regulation being
poor.

So this must include the power transformer also.

Yes it does.


Some have
considerably better regulation than others (to avoid mis-
interpretation again, by "transformer regulation" I mean the
term in the way that Sowter and Lundahl use it: i.e the
variation in output voltage between no load and full load)

That's how I use it too.


This is what I tend to do, but I also don't believe in 'going over the
top' with it !

I would be interested to know what you define as
"over the top" As I mentioned before, I have just been listening
to a Swedish built amp with 100uF-10H-200uF-10H-200uF-5k6-200uF.
That seems to me to be a little "over the top" The first choke had a 1A
rating. But it was a "money no object" design by the designer who
demonstrated it to me, for a very discerning client.

It's clear from what I've heard here that those who like tubes are indeed
captivated by their added distortions.

:-)

It is not difficult to cosnstruct a pp 50W tube amp with THD of
0.1% at 1kHz full power and a noise floor of about 150µV (weighted)
I have built several.

http://www.kolumbus.fi/iain.churches...em/C50_002.jpg

At lowish power (enough to fill the average listening room with music)
the THD is 0.03% Do you think that you, or any of the rest of us can
even detect this "added distortion" let alone be captivated by it?

I could elaborate at great length.

Please do. That's what we come here for:-)

I don't consider it wasted time, it's been quite an education actually and
also
because I wanted to find out for myself what all the fuss was about. I
additionally have a decent working knowledge of this area of electronics.

As do most people who build valve amps. The best way to find
out what all the fuss is about is to build one:-)

I live in Scandinavia, and so the situation here might not be parallel to
yours, but here, particularly in the past ten years, there has been a
considerable migration from SS to tube amps, by people who were
not satisfied with what they were hearing. I cannot recall one single
case of someone going the other way:-))

In addition, here, the very top of high end audio is dominated by tube amps
for which there is often a waiting list. In contrast, one can by a Krell
over the counter at a very good discount.

In the end, it all
comes down to reproducing music. Many people feel that a valve/tube
amp give a more musical performance (for whatever reason) This is why
tube amps are so popular. This seems to bother you.

Not for one moment.

It does bother me that some ppl see *their* idea of amplification to be
superior
based on nothing more than something like religious fervour though and
totally (
apparently ) to the contradiction of the scientific method.

:-)) I have never come across this "religious fervour" - a term often used
by the anti tube faction. They also talk about "snob value" etc. I have
never come across this either.

I belong to a "recorded music group" with some thirty members. More
than half of these now have tube amps. These people are not in the least
concerned with snob value or religious fervour, they are simply looking
for the system (amp and speakers) which will reproduce the music to
which they listen in the way which they think it should be reproduced.
It matters not a jot to them if the amp is SS, tube, or powered by North
Sea gas. It's that simple.

regards to all
Iain