[Wink]

I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave

[Mark D. Zacharias[_2_]]

"Wink" wrote in message
...
I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave


Ought to work fine.

Mark Z.

[Dave Platt]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Just a guess, but: if you're dropped the rail voltage, you may also
have disturbed the biasing of one or more of the amplifier's stages.
The drivers or finals could now be running with a lower level of
standing current... and if this is too low, the amp might be suffering
from some amount of crossover distortion.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Kevin McMurtrie]

In article , Wink
wrote:

I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave

If this is one of those fancy amplifiers where the pull-up and pull-down
are perfectly balanced, then it probably has minimal regulation on the
bias currents. It will change sound if the average power supply voltage
is too far off. 53V minus load drooping is probably out of normal
operating range.

--
I don't read Google's spam. Reply with another service.

[Wink]

Interesting answers guys. That pa-3d driver card is designed to
operate over a wide voltage range. It is used in the DH-500 which has
90 volt rails. I'll have to talk John Hillig at Musical Concepts about
this. The waveform is fully integrated at something like 17 V rails
and 70 ma. idle bias.

The card uses a single ended front end and I believe Cascoded current
follower output device drivers.

These blocks sound pretty good with Chemi-cons (not old stock
Sangamos) at the 63 V design rail voltage Frankly though, I bought
Clayton S-40, 50 W class A per channel, and it is verging on magical.

I have doubts about whether my blocks will ever compete. Not the
result I was seeking.
Dave




On Sun, 23 Mar 2008 12:35:17 -0500, Wink wrote:

I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave

[Arny Krueger]

"Wink" wrote in message


I happened to snag a set of 63V/10,000ufd FK BG caps for
my monoblock PSUs. The rail voltage with stock Hafler
xmfr is ~ 63 Volts so to avoid exploding my $$ BGs, I'm
using a Variac to reduce the AC mains input for a rail
Voltage of ~ 53 volts until I replace the Hafler trafos
with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

Running 63 volt rated caps at 63 volts will probably not cause explosions,
but it will shorten their useful life to spec, given other operating
conditions are spec. Since you probably aren't running them as warm as spec,
they will probably still live longer than spec. Furthermore, its not like
electrolytics explode if run 1 volt over spec. They can probably take 20% or
more overvoltage, with no undesireably results other than a somewhat
shortened life.

Bottom line, you could experiment for a few minutes or a few hours with
rated power line voltage being appled, and nothing bad would happen.

The mystery is the sound, which is sort of peculiar.

And of course, being an unwashed amateur, you have no proper listening tests
to back this up. With all due respect, which ain't much, why would anybody
with a brain even comment on your random perceptions?

You probably are scrunching up your ears every time you listen to these amps
because you *know* about the *violence* that is going on inside. Come back
when you've got evidence of something more electronic and technical than the
state of your mind. :-(

Hard to explain, but what is the source?

Your state of mental stress due to your under-rated caps, which aren't all
that under-rated?

Of course there are 3
variables that have been changed: PSU caps from Chemicons
to BGs, lower rail voltage (well within the operating
range of the PA-3D driver board), and inclusion of the
Variac twixt house mains and both amps.

Not to mention your obvious state of guilt and self-deinal.

Should I expect some odd interaction between the Variac
and existing Hafler power xfmr? Nothing obvious comes to
mind. Running stone cold, the 1500VA, Powerstat Variac
has plenty of capacity.

Well, the Variac probably adds a little ESR, and may shift the harmonic
content of the powerline measurably. But on balance, those are the sorts of
thing that a well-designed power amp is supposed to take in stride.

Not much to go on here, but thought I would throw this
one out to you guys.

If the origional caps were OK, then the added/replaced caps were acts of
either futility or obsessive behavior. If they weren't OK, why didn't you
get proper caps instead of inflicting this marginally-rated crap on your
psyche?

Seriously!

As far as the bias-shift theory goes, the fact is that a well-designed power
amp can't be allowed to suddenly fall apart because the rail voltages are
20% or whatever low.

IME a lot of power amp output stages will do a credible job of amplifying
when the rail voltage is 20% of spec. Not 20% low, but 20% of. Of course the
power output will be only about 10% of spec, but what do you expect, power
from no where? ;-)

[jamesgangnc[_3_]]

Why did you change the caps? Are the new ones larger? Trust me, the
electrons are not brand concious. They don't care what the label on the
caps is. Brand X is just the same as Brand Y to an electron. Now labels
and my teenage daughter, that's another story.....

The voltage tolerance on your caps is going to have safety factor so you can
run it at rated voltage.

"Wink" wrote in message
...
I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave

[Eeyore]

Arny Krueger wrote:

Running 63 volt rated caps at 63 volts will probably not cause explosions,
but it will shorten their useful life to spec, given other operating
conditions are spec

NO !

What kills capacitors is HEAT. The vast majority of that heat comes from the
effect of ripple current, absolutely NOT applied voltage which merely affects
the leakage current.

A 63V rated cap is *designed* to be used at 63V. It will likely have a 'surge
rating' of around 80V but that's rarely publicised these days.


Graham

[Eeyore]

Wink wrote:

I'm not running 800 bucks worth of 63 V lytics at 63 Volts. Not
necessary.

What a shocking waste of money !

Transistor amps by design (large degrees of negative feedback whether local,
overall or both) and by virtue of the inherent high collector resistance of the
active devices are very little affected by signal on the power rails.

In any case, the AC voltage on the DC rails will be mostly 100/120 Hz ripple. And
fitting Black Gates will make ZERO difference to that.

At best you've simply not made your amp any WORSE by fitting BGs but it's an
insane waste of money. What on earth did you expect it to do and most of all **
WHY ** ?

Graham

[Eeyore]

jamesgangnc wrote:

Why did you change the caps? Are the new ones larger? Trust me, the
electrons are not brand concious. They don't care what the label on the
caps is. Brand X is just the same as Brand Y to an electron. Now labels
and my teenage daughter, that's another story.....

Well ... different caps may have different ESRs which will slightly influence
the ripple voltage but that's only a minor secondary effect compared to the
capacitance value in this kind of PSU.


The voltage tolerance on your caps is going to have safety factor so you can
run it at rated voltage.

Absolutely.

Graham

[Michael Black]

"jamesgangnc" ) writes:
Why did you change the caps? Are the new ones larger? Trust me, the
electrons are not brand concious. They don't care what the label on the
caps is. Brand X is just the same as Brand Y to an electron. Now labels
and my teenage daughter, that's another story.....

The voltage tolerance on your caps is going to have safety factor so you can
run it at rated voltage.

I just reread that.

So he changed the capacitors, and "made do" with lower voltage than needed,
and now he's talking about getting a new transformer with a lower voltage to
keep the capacitors safe.

Even if there had been some value in changing the filter capacitors, it
was silly to change them to lower voltage ones, and the moreso if that
requires yet another change, the transformer.

Plus, he thinks it sounds different with the variac. But if as some
suggest that's because the unit is running at a lower voltage, then
he'll still have that problem when he changes the transformer.

Michael

"Wink" wrote in message
...
I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave

[Eeyore]

Wink wrote:

These blocks sound pretty good with Chemi-cons (not old stock
Sangamos) at the 63 V design rail voltage

Your obsession with capacitor brand is quite absurd. Look elsewhere for
what's causing any apparent difference.

Graham

[Wink]

A glorious response. Curious in light of previous helpful and cordial
ones, free of your compulsive cruelty.

I'm not an objectivist Arny. I've tried to be, the scientist within
compels it; but amps sound different, quite different frequently.

ICs and cables: I've been a maximum skeptic for decades, using
generics and zip cord. But recent experiments have shown that these
items do indeed sound different, frequently meaningfully. It is
distressing, looking for the physics, and the yet the conclusion is
inescapable.

I'm convinced that, though objectivists do not necessarily have
inferior ears, they may have ears which are insensitive to things the
subjectivists detect. Like my wife who can distinguish colors that
look utterly the same to me.

AB, ABX testing is useless. Sometimes amp problems/ strengths take
weeks to emerge. The instantaneous nature of the AB test does not
allow enough time for the ear-brain to acquire the target. This is not
true of speakers generally because of the massive differences between
designs. Sufficient differential for near instant target acquisition.

Anyway, keep the responses coming. I need smattering of high quality,
gratuitous immaturity in my day, and yours is of the highest quality.

I'm not running 800 bucks worth of 63 V lytics at 63 Volts. Not
necessary.
Dave


On Mon, 24 Mar 2008 09:27:16 -0400, "Arny Krueger"
wrote:

"Wink" wrote in message


I happened to snag a set of 63V/10,000ufd FK BG caps for
my monoblock PSUs. The rail voltage with stock Hafler
xmfr is ~ 63 Volts so to avoid exploding my $$ BGs, I'm
using a Variac to reduce the AC mains input for a rail
Voltage of ~ 53 volts until I replace the Hafler trafos
with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

Running 63 volt rated caps at 63 volts will probably not cause explosions,
but it will shorten their useful life to spec, given other operating
conditions are spec. Since you probably aren't running them as warm as spec,
they will probably still live longer than spec. Furthermore, its not like
electrolytics explode if run 1 volt over spec. They can probably take 20% or
more overvoltage, with no undesireably results other than a somewhat
shortened life.

Bottom line, you could experiment for a few minutes or a few hours with
rated power line voltage being appled, and nothing bad would happen.

The mystery is the sound, which is sort of peculiar.

And of course, being an unwashed amateur, you have no proper listening tests
to back this up. With all due respect, which ain't much, why would anybody
with a brain even comment on your random perceptions?

You probably are scrunching up your ears every time you listen to these amps
because you *know* about the *violence* that is going on inside. Come back
when you've got evidence of something more electronic and technical than the
state of your mind. :-(

Hard to explain, but what is the source?

Your state of mental stress due to your under-rated caps, which aren't all
that under-rated?

Of course there are 3
variables that have been changed: PSU caps from Chemicons
to BGs, lower rail voltage (well within the operating
range of the PA-3D driver board), and inclusion of the
Variac twixt house mains and both amps.

Not to mention your obvious state of guilt and self-deinal.

Should I expect some odd interaction between the Variac
and existing Hafler power xfmr? Nothing obvious comes to
mind. Running stone cold, the 1500VA, Powerstat Variac
has plenty of capacity.

Well, the Variac probably adds a little ESR, and may shift the harmonic
content of the powerline measurably. But on balance, those are the sorts of
thing that a well-designed power amp is supposed to take in stride.

Not much to go on here, but thought I would throw this
one out to you guys.

If the origional caps were OK, then the added/replaced caps were acts of
either futility or obsessive behavior. If they weren't OK, why didn't you
get proper caps instead of inflicting this marginally-rated crap on your
psyche?

Seriously!

As far as the bias-shift theory goes, the fact is that a well-designed power
amp can't be allowed to suddenly fall apart because the rail voltages are
20% or whatever low.

IME a lot of power amp output stages will do a credible job of amplifying
when the rail voltage is 20% of spec. Not 20% low, but 20% of. Of course the
power output will be only about 10% of spec, but what do you expect, power
from no where? ;-)

[Eeyore]

Michael Black wrote:

Plus, he thinks it sounds different with the variac. But if as some
suggest that's because the unit is running at a lower voltage, then
he'll still have that problem when he changes the transformer.

Absolutely correct.

The entire plan is flawed from the ouset, although of course there is NO NEED to
'under-run' the caps.

Graham

[Eeyore]

Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.

Simple reason for that, it's how the amp originally sounded when the Sangamos
were 'fresh'.

As caps 'die', their capacitance reduces and this affects the regulation of the
power supply and consequently can influence how it treats large dynamics.

All you did was restore the amp to 'original condition' but didn't like the
result.

If perhaps you'd fitted 3300 or 4700uF caps in place of 10,000uF you may have
preferred how it sounded.

Science DOES have the answers you see, but you really do need to know your onions
and have LOTS of experience to understand this stuff. Random component
substitution is one of the dumbest things out there but a lot of crooks make good
money out of you from it.


Graham

[jakdedert]

Eeyore wrote:

Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.

Duh....

Simple reason for that, it's how the amp originally sounded when the Sangamos
were 'fresh'.

Why does that not make sense to 'audiophiles'...and by what objective
measurement were the originals starting to 'die'?

As caps 'die', their capacitance reduces and this affects the regulation of the
power supply and consequently can influence how it treats large dynamics.

All you did was restore the amp to 'original condition' but didn't like the
result.

If perhaps you'd fitted 3300 or 4700uF caps in place of 10,000uF you may have
preferred how it sounded.

Probably, but only if they cost at least $200 per cap....

Science DOES have the answers you see, but you really do need to know your onions
and have LOTS of experience to understand this stuff. Random component
substitution is one of the dumbest things out there but a lot of crooks make good
money out of you from it.

He should have new control knobs machined out of solid gold. Now THAT
would provide some measurable change...opens up the soundstage and
provides unimaginable depth and clarity to the imaging.


Seriously, if the OP wants to use those 'bargain' $800 caps, perhaps he
should build an entire new pair of blocs with those and the new
transformers he's having custom built...and sell the originals. There
are plenty of plans on the Web. Of course it sounds like money is not
an object, so perhaps he could use the old ones as doorstops.

jak


Graham

[Wink]

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound. This
has not changed much despite break-in, assuming electrolytic
"break-in" actually occurs. (Of course the LC-200s have 3x the
capacitance. Yes I've read esp's treatment on this.)

I was going to continue with the MC caps when I built the monoblocks,
but found a set of 4 - 63 V, 10 kufd FK series Black Gates for a
"reasonable" price and thought I'd roll the dice.

Are the new ones larger? Trust me, the
electrons are not brand concious. They don't care what the label on the
caps is. Brand X is just the same as Brand Y to an electron.
Yes, of course. I expect Brand X could be labeled Fruit Loops and
Brand Y, Captain Crunch. That would not make a difference. Differences
in internal design, well...I suppose that COULD make a difference, but
probably not. I think you've made such brand observations before,
which make -- of course -- no sense whatsoever.

The voltage tolerance on your caps is going to have safety factor so you can
run it at rated voltage.
Yes, I'm aware of this, but why do so if unnecessary? I was going to
change the xfmrs anyway. Avel Lindberg has as a standard model a dual
40 V secondary unit of suitable physical dimensions. Seems logical
since as pointed out the amp will operate properly over a wide range
of voltages.

It turns out that I'm not going with AL toroidals, but am having them
custom made by a Canadian company -- Richard Sumner. I could specify
any secondary voltage, but 40-0-40 gives 56.6 V calculated no-load,
about 53 V under load at idle. A 10 Volt safety margin with negligible
performance penalties.
Dave

"Wink" wrote in message
.. .
I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave

[Arny Krueger]

"Wink" wrote in message


A glorious response. Curious in light of previous helpful
and cordial ones, free of your compulsive cruelty.

The kindest thing I can say to someone who is making decisions based on
questionable information...

I'm not an objectivist Arny.

Neither am I.

I've tried to be, the
scientist within compels it; but amps sound different,
quite different frequently.

It always happens for a reason, and the reason often has nothing to do with
amplifier performance. It often has to do with the circumstances of the
listening evaluation.

ICs and cables: I've been a maximum skeptic for decades,
using generics and zip cord. But recent experiments have
shown that these items do indeed sound different,
frequently meaningfully. It is distressing, looking for
the physics, and the yet the conclusion is inescapable.

No such thing - try doing some reasonable tests.

I'm convinced that, though objectivists do not
necessarily have inferior ears, they may have ears which
are insensitive to things the subjectivists detect.

Interesting how the subjectivist's ears work the same when the sighted cues
and other asymmetries are removed from the evaluation.

Like my wife who can distinguish colors that look utterly the
same to me.

OK, so you are a little color blind.

AB, ABX testing is useless.

So how do you do a listening test? Any comparison of two pieces of
equipment can be called an AB test.

Sometimes amp problems
strengths take weeks to emerge.

If it is real, there is always a reason.

The instantaneous nature
of the AB test does not allow enough time for the
ear-brain to acquire the target.

Who said that an AB test has to be instantaneous?

I've heard this straw man argument 100's of times. :-(

This is not true of
speakers generally because of the massive differences
between designs. Sufficient differential for near instant
target acquisition.

Maybe yes, maybe no.

Anyway, keep the responses coming. I need smattering of
high quality, gratuitous immaturity in my day, and yours
is of the highest quality.

Actually, some of the original ABX crew is now well on their way to their
70s, and their immaturity is such that they have credibility in the audio
industry that you probably don't even know exists.

Immaturity, indeed. :-(

I'm not running 800 bucks worth of 63 V lytics at 63
Volts. Not necessary.

You paid $800 for the electrolytics for a power amp or two?

Freakin' unbelievable. :-(

[[email protected]]

On Mar 24, 1:36*pm, Wink wrote:
Why did you change the caps? *

When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately *a deadening of the sound. This
has not changed much despite break-in, assuming electrolytic
"break-in" actually occurs. (Of course the LC-200s have 3x the
capacitance. Yes I've read esp's treatment on this.)

I was going to continue with the MC caps when I built the monoblocks,
but found a *set of 4 - 63 V, 10 kufd FK series Black Gates for a
"reasonable" price and thought I'd roll the dice.

Are the new ones larger? *Trust me, the
electrons are not brand concious. *They don't care what the label on the
caps is. *Brand X is just the same as Brand Y to an electron. *

Yes, of course. I expect Brand X could be labeled Fruit Loops and
Brand Y, Captain Crunch. That would not make a difference. Differences
in internal design, well...I suppose that COULD make a difference, but
probably not. *I think you've made such brand observations before,
which make -- of course -- no sense whatsoever.

The voltage tolerance on your caps is going to have safety factor so you can
run it at rated voltage.

Yes, I'm aware of this, but why do so if unnecessary? I was going to
change the xfmrs anyway. Avel Lindberg has as a standard model a dual
40 V secondary unit of suitable physical dimensions. Seems logical
since as pointed out the amp will operate properly over a wide range
of voltages. *

It turns out that I'm not going with AL toroidals, but am having them
custom made by a Canadian company -- Richard Sumner. I could specify
any secondary voltage, but 40-0-40 gives 56.6 V calculated no-load,
about 53 V under load at idle. A 10 Volt safety margin with negligible
performance penalties.
Dave



"Wink" wrote in message
.. .
I happened to snag a set of 63V/10,000ufd FK BG caps for my monoblock
PSUs. The rail voltage with stock Hafler xmfr is ~ *63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts until I replace the Hafler
trafos with lower sec V Toroidals. [Refer to "Hafler Monoblock
Project..." thread]

The mystery is the sound, which is sort of peculiar. Hard to explain,
but what is the source? Of course there are 3 variables that have been
changed: PSU caps from Chemicons to BGs, lower rail voltage (well
within the operating range of the PA-3D driver board), and inclusion
of the Variac twixt house mains and both amps.

Should I expect some odd interaction between the Variac and existing
Hafler power xfmr? Nothing obvious comes to mind. *Running stone cold,
the 1500VA, Powerstat Variac has plenty of capacity.

Not much to go on here, but thought I would throw this one out to you
guys. Thanks again...
Dave- Hide quoted text -

- Show quoted text -

Seems like a whole lot of time, effort, and money being spent to run a
lower output stage voltage. To each his own.

[Arny Krueger]

"Eeyore" wrote in
message

Wink wrote:

I'm not running 800 bucks worth of 63 V lytics at 63
Volts. Not necessary.

Did we read this right? Is this a typo? Was there an extra zero in that
price?

What a shocking waste of money !

Agreed.

Transistor amps by design (large degrees of negative
feedback whether local, overall or both) and by virtue of
the inherent high collector resistance of the active
devices are very little affected by signal on the power
rails.

Agreed.

In any case, the AC voltage on the DC rails will be
mostly 100/120 Hz ripple. And fitting Black Gates will
make ZERO difference to that.

Agreed.

At best you've simply not made your amp any WORSE by
fitting BGs but it's an insane waste of money. What on
earth did you expect it to do and most of all ** WHY ** ?

Graham, I don't think we should waste much time on a certifiable loonie who
puts $400-800 worth of caps in a single amplifier. He's living in a
different universe from the rest of of!

[Eeyore]

jakdedert wrote:

Eeyore wrote:
Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.

Duh....

Why the duh ?


Simple reason for that, it's how the amp originally sounded when the Sangamos
were 'fresh'.

Why does that not make sense to 'audiophiles'...

Because they mostly reject scientific reasoning, thinking that subjectivity is superior
even though they can't explain why except by resorting to make-believe words and ideas.



and by what objective
measurement were the originals starting to 'die'?

A good question.

It would be VERY interesting to know what value they still had when removed.


As caps 'die', their capacitance reduces and this affects the regulation of the
power supply and consequently can influence how it treats large dynamics.

All you did was restore the amp to 'original condition' but didn't like the
result.

If perhaps you'd fitted 3300 or 4700uF caps in place of 10,000uF you may have
preferred how it sounded.

Probably, but only if they cost at least $200 per cap....

For ordinary commercial 3300/4700 63Vs ? A few dollars each. I'm sure you can get them
less than $10.


Science DOES have the answers you see, but you really do need to know your onions
and have LOTS of experience to understand this stuff. Random component
substitution is one of the dumbest things out there but a lot of crooks make good
money out of you from it.

He should have new control knobs machined out of solid gold. Now THAT
would provide some measurable change...opens up the soundstage and
provides unimaginable depth and clarity to the imaging.

LOL !

You've seen those wooden knobs for several hundred dollars each ?

Graham

[Eeyore]

wrote:

Seems like a whole lot of time, effort, and money being spent to run a
lower output stage voltage. To each his own.

It's completely NUTS.

He must have a LOT more money than sense.

You could buy some seriously good NEW amplifiers for the time money and effort
that's gone into badly restoring a very old pair.

Graham

[Eeyore]

Wink wrote:

The rail voltage with stock Hafler xmfr is ~ 63 Volts so to
avoid exploding my $$ BGs, I'm using a Variac to reduce the AC mains
input for a rail Voltage of ~ 53 volts

You first misunderstanding.

If BG's ** EXPLODE ** with the rated voltage applied that simply shows
that they're garbage. Competently manufactured electrolytic caps will not
be troubled by as much as 20-25% overvoltage in fact as long as it's not
continuous.

Graham

[Eeyore]

Arny Krueger wrote:

"Eeyore" wrote in

At best you've simply not made your amp any WORSE by
fitting BGs but it's an insane waste of money. What on
earth did you expect it to do and most of all ** WHY ** ?

Graham, I don't think we should waste much time on a certifiable loonie who
puts $400-800 worth of caps in a single amplifier. He's living in a
different universe from the rest of of!

I do like to (try to) explain to the crazies that there are actually perfectly
'sound' - lol - scientific reasons for what they appear to think are mysterious
differences that they then attribute to component swaps or some kind of magick
generally.

It's a hard task but someone's got to do it !

Graham

[Arny Krueger]

"Eeyore" wrote in
message
jakdedert wrote:

Eeyore wrote:
Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die
several years ago, I replaced them with Musical
Concepts 80V, 27 kufd LC-200s made by Chemi-con, and
noticed immediately a deadening of the sound.

Duh....

Why the duh ?


Simple reason for that, it's how the amp originally
sounded when the Sangamos were 'fresh'.

Why does that not make sense to 'audiophiles'...

Because they mostly reject scientific reasoning, thinking
that subjectivity is superior even though they can't
explain why except by resorting to make-believe words and
ideas.



and by what objective
measurement were the originals starting to 'die'?

A good question.

It would be VERY interesting to know what value they
still had when removed.


As caps 'die', their capacitance reduces and this
affects the regulation of the power supply and
consequently can influence how it treats large
dynamics.

All you did was restore the amp to 'original condition'
but didn't like the result.

If perhaps you'd fitted 3300 or 4700uF caps in place of
10,000uF you may have preferred how it sounded.

Probably, but only if they cost at least $200 per cap....

For ordinary commercial 3300/4700 63Vs ? A few dollars
each. I'm sure you can get them less than $10.

http://search.digikey.com/scripts/Dk...?name=P7511-ND

Price = $8.15 in lots of one.

Oops! They are 80 volt parts. ;-)


Science DOES have the answers you see, but you really
do need to know your onions and have LOTS of experience
to understand this stuff. Random component substitution
is one of the dumbest things out there but a lot of
crooks make good money out of you from it.

He should have new control knobs machined out of solid
gold. Now THAT would provide some measurable
change...opens up the soundstage and provides
unimaginable depth and clarity to the imaging.

LOL !

You've seen those wooden knobs for several hundred
dollars each ?

I have seen some incredible glowing testimonials for them.

[Jerry Peters]

Wink wrote:
A glorious response. Curious in light of previous helpful and cordial
ones, free of your compulsive cruelty.

I'm not an objectivist Arny. I've tried to be, the scientist within
compels it; but amps sound different, quite different frequently.

ICs and cables: I've been a maximum skeptic for decades, using
generics and zip cord. But recent experiments have shown that these
items do indeed sound different, frequently meaningfully. It is
distressing, looking for the physics, and the yet the conclusion is
inescapable.

I'm convinced that, though objectivists do not necessarily have
inferior ears, they may have ears which are insensitive to things the
subjectivists detect. Like my wife who can distinguish colors that
look utterly the same to me.

Actually there is a possible scientific explanation for this: a small
number of women can actually see far more colors than the usual 16
million or so. I forget the details, but their retinal structure is
actually different.

Jerry

[Arny Krueger]

"Wink" wrote in message


A new stock DH-200 or 220 doesn't sound dead.

Neither does a used one in good shape with commodity power supply caps @
$10 each.

Science has the potential to have all the answers. It
doesn't follow that is has all the answers currently.

But audio isn't rocket science and it isn't high energy physics, either.

We've got all the answers we need to understand why things sound different.

The trough job is getting true believers to do proper listening tests.

I think YOU think you know what you're talking about, but
really don't.

Prove it.

And I suspect you know this.

Doesn't follow,

[Eeyore]

Jerry Peters wrote:

Wink wrote:
A glorious response. Curious in light of previous helpful and cordial
ones, free of your compulsive cruelty.

I'm not an objectivist Arny. I've tried to be, the scientist within
compels it; but amps sound different, quite different frequently.

ICs and cables: I've been a maximum skeptic for decades, using
generics and zip cord. But recent experiments have shown that these
items do indeed sound different, frequently meaningfully. It is
distressing, looking for the physics, and the yet the conclusion is
inescapable.

I'm convinced that, though objectivists do not necessarily have
inferior ears, they may have ears which are insensitive to things the
subjectivists detect. Like my wife who can distinguish colors that
look utterly the same to me.

Actually there is a possible scientific explanation for this: a small
number of women can actually see far more colors than the usual 16
million or so. I forget the details, but their retinal structure is
actually different.

Precisely. If you actually look in enough detail, you'll find the
scientific exaplanation. The audio subjectivists don't even try looking
though. They see and hear only what they want to believe. It's like a
religion.

Graham

[Eeyore]

Wink wrote:

A new stock DH-200 or 220 doesn't sound dead.

We only have your word for that. When did you last hear one in *ORIGINAL* condition
with PSU capacitors at their orignal value ?


Science has the potential to have all the answers. It doesn't follow
that is has all the answers currently.

In this instance science most certainly DOES have the answer.

Your old caps had reduced capacitance through aging. That's why new ones of the
correct originally specified value sounded different. That would be the case
regardless of the brand name on the can.

Graham

[Eeyore]

Wink wrote:

I think YOU think you know what you're talking about, but really
don't. And I suspect you know this.

I'm a pro-audio designer who's worked with some of the best in the busines and I'm
something of an expert about amplifier design.

I suspect you need to get a life and stop believing voodoo nonsense. You'll find you
have a lot more spare cash too.

Graham

[Eeyore]

Wink wrote:

Why does that not make sense to 'audiophiles'...and by what objective
measurement were the originals starting to 'die'?
Loss of bass control. Serious enough to be quite objective. I
initially thought the surrounds on the woofers were coming unglued.

That sounds like something more serious. Do you really know what you're
doing poking around inside amps ?

What ELSE did you touch (possibly inadvertantly).


Seriously, if the OP wants to use those 'bargain' $800 caps, perhaps he
should build an entire new pair of blocs with those and the new
transformers he's having custom built...and sell the originals. There
are plenty of plans on the Web. Of course it sounds like money is not
an object, so perhaps he could use the old ones as doorstops.
This is what I've done Jak, using John Hillig's driver cards. The caps
and xmfrs are the final additions. All that remains of the original
220's are chassis, mosfets, and xfmrs.

Why on earth are you wasting your time mucking about with an ancient amp ?
Technology has moved on although I confess I have a soft spot for mosfet
amps. When really well designed and set up they have miniscule (high order)
crossover distortion compared to bipolars. Indeed one of my own mosfet
designs had vanishingly low THD and most of what could be measured was 2nd
harmonic which is sonically the least intrusive.

Graham

[Eeyore]

Wink wrote:

Seems like a whole lot of time, effort, and money being spent to run a
lower output stage voltage. To each his own.

63 V BGs were available for a deal, albeit a relative deal -- no
question.

80 V versions are gone. This is the only reason I'm lowering the rail
voltage.

They'll be totally fine at 63V. At least you can then rule out bias
variations caused by the lower voltage operation.

Graham

[Wink]

A new stock DH-200 or 220 doesn't sound dead.

Science has the potential to have all the answers. It doesn't follow
that is has all the answers currently.

I think YOU think you know what you're talking about, but really
don't. And I suspect you know this.


Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.

Simple reason for that, it's how the amp originally sounded when the Sangamos
were 'fresh'.

As caps 'die', their capacitance reduces and this affects the regulation of the
power supply and consequently can influence how it treats large dynamics.

All you did was restore the amp to 'original condition' but didn't like the
result.

If perhaps you'd fitted 3300 or 4700uF caps in place of 10,000uF you may have
preferred how it sounded.

Science DOES have the answers you see, but you really do need to know your onions
and have LOTS of experience to understand this stuff. Random component
substitution is one of the dumbest things out there but a lot of crooks make good
money out of you from it.


Graham

[Wink]

Why does that not make sense to 'audiophiles'...and by what objective
measurement were the originals starting to 'die'?
Loss of bass control. Serious enough to be quite objective. I
initially thought the surrounds on the woofers were coming unglued.

Seriously, if the OP wants to use those 'bargain' $800 caps, perhaps he
should build an entire new pair of blocs with those and the new
transformers he's having custom built...and sell the originals. There
are plenty of plans on the Web. Of course it sounds like money is not
an object, so perhaps he could use the old ones as doorstops.
This is what I've done Jak, using John Hillig's driver cards. The caps
and xmfrs are the final additions. All that remains of the original
220's are chassis, mosfets, and xfmrs.

[dizzy]

Eeyore wrote:

wrote:

Seems like a whole lot of time, effort, and money being spent to run a
lower output stage voltage. To each his own.

It's completely NUTS.

Quite bizarre, to spend all that money on caps that are so incorrect
that he thinks he needs variacs...

[Wink]

Seems like a whole lot of time, effort, and money being spent to run a
lower output stage voltage. To each his own.

63 V BGs were available for a deal, albeit a relative deal -- no
question.

80 V versions are gone. This is the only reason I'm lowering the rail
voltage.

[jakdedert]

Eeyore wrote:

jakdedert wrote:

Eeyore wrote:
Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.
Duh....

Why the duh ?

Duh = 'obvious'. If the caps were actually 'dying', then replacing them
would improve the sound...same point you made below.

Simple reason for that, it's how the amp originally sounded when the Sangamos
were 'fresh'.

Why does that not make sense to 'audiophiles'...

Because they mostly reject scientific reasoning, thinking that subjectivity is superior
even though they can't explain why except by resorting to make-believe words and ideas.



and by what objective
measurement were the originals starting to 'die'?

A good question.

It would be VERY interesting to know what value they still had when removed.


As caps 'die', their capacitance reduces and this affects the regulation of the
power supply and consequently can influence how it treats large dynamics.

All you did was restore the amp to 'original condition' but didn't like the
result.

If perhaps you'd fitted 3300 or 4700uF caps in place of 10,000uF you may have
preferred how it sounded.

Probably, but only if they cost at least $200 per cap....

For ordinary commercial 3300/4700 63Vs ? A few dollars each. I'm sure you can get them
less than $10.

Yeah, but 'ordinary' capacitors for a few bucks each don't 'sound as
good'. $200 caps--identical in every way, but for appearance and price
tag--'sound' better...or so the OP would have us believe.

Science DOES have the answers you see, but you really do need to know your onions
and have LOTS of experience to understand this stuff. Random component
substitution is one of the dumbest things out there but a lot of crooks make good
money out of you from it.
He should have new control knobs machined out of solid gold. Now THAT
would provide some measurable change...opens up the soundstage and
provides unimaginable depth and clarity to the imaging.

LOL !

You've seen those wooden knobs for several hundred dollars each ?

Oh year...then there are the 'magic rocks' that you put in each corner
of the room; the speaker cable towers, the wall *outlet covers* (of all
damn things!), the...ad nauseum.

jak

Graham

[jakdedert]

Wink wrote:
A new stock DH-200 or 220 doesn't sound dead.

Science has the potential to have all the answers. It doesn't follow
that is has all the answers currently.

I think YOU think you know what you're talking about, but really
don't. And I suspect you know this.

I suspect you pay a lot of money for nothing. Probably you have a lot
of money to spend on nothing. Fine. You just won't get much sympathy
for snake-oil hawkers in a forum of objective audio (mostly) professionals.

You've taken the word (or falling for the BS...your choice) of people
who are simply taking your money and laughing behind your back. Then
you come here and try to convince us that the Emperor's New Outfit is so
exquisite that only you and a select few like you, with Certified Golden
Eyes (ears)--and lots of money--can perceive it. Trouble is, that
people who really do know--can't...and they're laughing, too.

OTOH, it's your money. 'Spend it wisely' probably never entered your
lexicon. You'd probably get a lot more mileage out of it if you gave it
away to somebody who could actually use it, as opposed to enriching
pseudo-scientific, alchemist charlatans.

YMMV....

jak

[Eeyore]

jakdedert wrote:

Eeyore wrote:
jakdedert wrote:
Eeyore wrote:
Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.
Duh....

Why the duh ?

Duh = 'obvious'. If the caps were actually 'dying', then replacing them
would improve the sound...same point you made below.

'Improve' depends on subjectivity. Make different for sure. It seems the OP felt it was
inferior despite the fact, that's how the amps were designed.

However his later comments make me think he may have disturbed something else if the sound
really deteriorated badly.

Graham

[jakdedert]

Eeyore wrote:

jakdedert wrote:

Eeyore wrote:
jakdedert wrote:
Eeyore wrote:
Wink wrote:

Why did you change the caps?
When the stock Hafler 10 kufd Sangamos started to die several years
ago, I replaced them with Musical Concepts 80V, 27 kufd LC-200s made
by Chemi-con, and noticed immediately a deadening of the sound.
Duh....
Why the duh ?
Duh = 'obvious'. If the caps were actually 'dying', then replacing them
would improve the sound...same point you made below.

'Improve' depends on subjectivity. Make different for sure. It seems the OP felt it was
inferior despite the fact, that's how the amps were designed.

However his later comments make me think he may have disturbed something else if the sound
really deteriorated badly.

Graham

His later comments make me think he wouldn't know if his amp was bad or
good. The only subjective measurement unit he's presented (beside ps
voltage) is US Dollars ($). More$ = Better sound. Many more$ = Much
Better Sound.

jak