Isolated, regulated, toroidal step down transformer AC power supply design.

[Bob Parker]

That is the first thing that you've said in here that I actually agree with
Phil.

Bob is a Pussy.

But you still didn't know that a voltage doubling rectifier CAN BE a
variant of the simple half wave rectifier.

Nar, nar, nan-nar-nar!!!

Boy, this is fun isn't it.

You really don't get it, do you Mark? It's all over your head like a
tent. I felt a bit sorry fot you and tried to steer you in the right
direction, but you won't listen.


Bob (the one Phil's comment was aimed at - you think)

 

[Mark]

There is probably about a million ...no, no, a billion things I don't "get",
but I've learnt not to worry about contingencies and just deal with matters
as they happen.

I would need a microscope to find your compassion, mate. That is one of the
defining characteristics of the 'Phil-o-phile'.

He has the hart of a Pussy.

 

[Trevor Wilson]

I realise that my breath is wholly wasted on this Philistine, but:

A regulated circuit can benefit from the pre-regulation of the incoming
AC.

**ANY pre-regulation should always be done at DC. AC regulation is
expensive, insane and unnecessary. With modern regulators, pre-regulation is
not likely to be required.

Specifically, where the incoming AC strays outside the operating range of
the regulating IC's output voltage, the benefits may include, for example,
not having any blue smoke emanating from the unit.

**Again. Proper selection of transformer will eliminate any problems.

Regulating IC's aren't expensive, so it seems a common sense precaution
to make, particularly where other work, (the replacement of the existing
wall-wart with a toroidal step down transformer) is envisaged. Which is
EXACTLY what I originally indicated.

**No, it is not what you originally indicated.

 

[Trevor Wilson]

I realise that my breath is wholly wasted on this Philistine, but:

A regulated circuit can benefit from the pre-regulation of the incoming
AC.

Specifically, where the incoming AC strays outside the operating range of
the regulating IC's output voltage, the benefits may include, for example,
not having any blue smoke emanating from the unit.

Regulating IC's aren't expensive, so it seems a common sense precaution
to make, particularly where other work, (the replacement of the existing
wall-wart with a toroidal step down transformer) is envisaged. Which is
EXACTLY what I originally indicated.

**BTW: Depending on your application (which you foolishly have declined to
tell us) a toroidal transformer may well be the WORST choice imaginable.
Toroidal transformers are certainly trendy and have a low radiated flux, but
they lose out to EI transformers in most other areas, including regulation
and line noise rejection. For the best line noise rejection, an 'R' core
transformer is best.

But you won't tell us what you are trying to do, so we really can't help
you.

 

[Poxy]

Well, I didn't think of searching for the '7815 datasheet', so fucking sue
me.

That shows that you are not experienced in working with electronics -
anybody who regularly does searches for component numbers would
automatically add "datasheet". Furthermore, anyone with electronics
experience would understand the operating characteristics of a common linear
regulator without needing to refer to a datasheet - it's really common,
basic stuff.

Either way, the cheapest solution is sounding like I should exchange the
7815 /7915 pair, for a pair that DOES have that 30V spec. and in so doing,
eliminate the possible cause of the observed clipping during voltage
overloads.

The first thing to do is measure voltages at key points - at the output of
the AC plugpack at the input of the regulators, at the output of the
regualtors etc. Boring I know, but that is how you start the diagnosis a
power supply problem. That you don't appear to realise that really basic
fact demonstrates a lack of knowledge and experience with simple power
supplies and suggests that you're not equipped to diagnose nor fix the
problem.

Also, I take umbrage (offence, to you) at your trite analogy. It isn't an
accurate portrayal of what happened or my actions or my motivations or my
attitude. I would welcome a point-by-point comparison of your analogy and my
behaviour.

My analogy, horribly misspelt as it probably was, was reasonable, if not as
amusing as I would have liked. You clearly don't get how challenging it is
to design and implement what you wanted - it's *really* complex stuff. By
comparison, getting a standard dual-rail, linear regulator power supply to
behave is trivial.

The more I think about it, Bob's advice is correct - you should get someone
with a solid background in electronics to fix your preamp for you.

Your PRESUMPTION that I must pay too much for my Black Gates is based on
what? An ASSUMPTION that I pay foolish prices. That is both insulting AND
ignorant (of how cheaply Black Gates can be purchased).

Hey, if they give the sparkling audio performance you like, fair enough. I
probably haven't paid enough attention to the musicality of the caps I buy.

I also take umberage to your allegation that I am not "being straight-up
with [this group]".

You reckon that if i was being honest I would say "Actually, I built the
engine, it's running badly, does anyone want to buy some really good fuel
filters?" Here is why I wouldn't say such a thing:

a) I didn't build the application, I modified it.

You never said that. It does explain a lot. In my analogy, it would be like
revealing that you'd modified your engine while at the same time giving the
strong impression you don't really know how engines work.

b) It isn't running badly (under nominal conditions), it sounds superb.
c) I am not SELLING anything.

That was a joke. Sorry. I was kind of thinking that if your "thing" didn't
end up working, you could recover some cash-money by Ebaying them fancy
caps.

I look forward to our point-by-point comparison of your analogy with my
behaviour. I can't find many comparisons at all. Do you do this often? (that
is: make up stupid analogies that just don't work).

Look, I've got nothing to add. I thought my insightful analogy would help
you understand why people responded to you with derision. Obviously you
still don't get it, and that seems to be because you don't have the
knowledge and experience in electronics to diagnose and solve the fault -
everything you say reinforces that fact.

Get someone who knows what they are doing to look at your device. If it's a
power supply problem they'll diagnose and fix it very quickly.

And you might be able to pay them in capacitors

 

[Trevor Wilson]

BUT I DON'T want to eliminate the half wave rectifier!!! It is
pre-existing inside the application.

I don't want to alter the application, at all and I would prefer not even
to discuss it.

I would like to point out that my original question deliberately had
NOTHING to do with the application. The easiest way to eliminate the
unwanted discussion is to not provide information on the application.

So, WE are stuck with AC as an input to the application. I wanted to
eliminate the AC/AC wall-wart transformer (which uses an Iron core
transformer) and replace if with a Toroidal core transformer.

Do I need to justify this choice as well?

**YOU don't have to justify anything. YOU should be aware that, for low
level audio applications, a toroidal transformer will be your worst choice.
See what happens when you tell us what you are doing? You get sensible
answers. Dump the toroidal and look for a decent 'R' core transformer.
Additionally, I suggest you dump the 78XX & 79XX regulators and redesign
with LM317/LM337 regulators. Much more significant than bothering with those
silly Blackgate caps.

 

[budgie]

Black Gate Electrolytic Capacitors
----------------------------------

There are very few audio parts that promise a guaranteed improvement
when replacing practically any other part, but this is what the BLACK
GATE™ capacitors actually do. Exchanging any electrolytic capacitor
anywhere in the circuit of a CD-player, amplifier or in the crossover of
a speaker will greatly improve sound quality. BLACK GATE™ are recognised
worldwide as the best electrolytics capacitors money can buy.

aaahhhh - the electrolytic equivalent of monster OFC cables ;-)

 

[Trevor Wilson]

aaahhhh - the electrolytic equivalent of monster OFC cables ;-)

**Not really. Monster Cables are designed to possess attractive cosmetics,
with no real regard for any tangible performance criteria. Blackgate caps,
OTOH, DO have some measurably significant parameters. HOWEVER, none of those
parameters is significant for power supply filtering. IOW: There are better
caps available, at lower cost for filtering. Mind you: After purchasing some
of those Dick Smith 'Joe Master' branded monstrosities once (and ONLY once)
I can readily understand why some purchasers would spend the Bucks for a cap
which is quite well made and performs respectably enough (Blackgate).

 

[swanny]

The way I understand it, the regulation that already occurs within the
application can only operate within a tolerance of the regulating IC's
nominal input voltage. The application is using 15 Volt DC regulators
(output), after the bridge rectifier, and can only operate (+/- x%) of 15
volts DC input.

The rectification of (nominally) 9 VAC I understood to result in 18 VDC
(ignoring any small voltage drop across the diodes). So even when the input
voltage is nominal,
the input voltage to the regulating IC's is only within 20% of their nominal
output.

Now what happens if the domestic supply voltage is not nominal?

If the domestic supply comes in at 264 VAC (+10%), the existing linear
regulator now supplies 9.9 VAC to the application, the bridge rectifier
doubles that to 19.8 VAC. The input voltage to the regulating IC's is now
only within 40% of their nominal output!

I monitor the domestic supply and regularly see voltages coming into our
house outside the range of +/- 10%.

One solution, of course, would be to redesign the power supply within the
application's case, including upgrading the regulating IC's input voltage
tolerance to at least 40% of its output, if such an IC can be found!

However space within the applications case would not allow for a toroidal
transformer, which I consider to be the optimum solution for a number of
reasons that I don't need to explain here (or maybe they will insist that I
do that as well?!!), and I have already invested considerable effort (and a
small amount of money) in upgrading the capacitors within the existing
application's power supply and really don't want to loose out on the already
considerable improvements I have made therein.

Quite frankly, I am astounded and reviled that such a simple request has
generated such a vile reaction from this group. I can only assume that it is
because they, like me, were unable to Goggle a suitable design. So as to
maintain their allusion of expertise and so they hide their inability to
self-design a suitable solution, with insults!

I wonder what would happen if I took a simular request for such a simple
thing to another newsgroup, say 'us.electronics', and pointed out to them
that 'aus.electronics' does not have a single contributor who can satisfy
the request. I wonder what they would say. "Too difficult", do you think?

Why do you need to regulate the input voltage to the regulator?
It is the function of the regulator to accept an unregulated input and provide a
stable, regulated output.

 

[Mark]

The subject of the OP was "Isolated, regulated, toroidal step down
transformer AC power supply design."

So I actually didn't indicate what 'it' was that was being replaced. Good on
you for making that observation.

Brevity and relevance play a part in the formulation of my subjects for
obvious reasons. Limited character space being one of them.

I did indicate what I wanted to replace 'it' with, in the subject matter of
the OP.

So OK, why don't you help me select the 'self regulating' transformer that
will eliminate all my over voltage problems. 240 VAC in (nominal), 9 VAC
out. Fused at about 2 amps at the input. (it isn't critical.)

Tell me what else you need to know and I'll decide what I tell you, or not.

Regarding your speculation that "with modern regulators, pre-regulation is
not likely to be required.":

"Not Likely" is a very soft qualification in the face of the observed
behaviour of the applications performance during times of over supply. A
100% correlation suggests that it is VERY LIKELY. Statistically significant,
in other words.

What isn't clear is why my Regs (assuming it is my Regs) misbehave. I have
already conceded that the most cost effective action for me to take would be
to replace the 7815/7915 pair with a new pair that DOES have the 30V spec.
and see what happens.

But I may have to replace all other Regs in the applications power supply,
for the same reason, before I get to the bottom of it. I don't have the
necessary test equipment or the expertise to pre-determine which Regs are at
fault.

Apparently AC regulation is a difficult task. TXU certainly do it VERY
BADLY.

 

[Trevor Wilson]

The subject of the OP was "Isolated, regulated, toroidal step down
transformer AC power supply design."

So I actually didn't indicate what 'it' was that was being replaced. Good
on you for making that observation.

Brevity and relevance play a part in the formulation of my subjects for
obvious reasons. Limited character space being one of them.

I did indicate what I wanted to replace 'it' with, in the subject matter
of the OP.

So OK, why don't you help me select the 'self regulating' transformer that
will eliminate all my over voltage problems. 240 VAC in (nominal), 9 VAC
out. Fused at about 2 amps at the input. (it isn't critical.)

**Obtain a signal generator, capable of delivering a stable 50Hz sine wave.
Operate it into a small (say) 50 Watt power amp. Drive the power amp into a
suitable power transformer. That'll work.

Tell me what else you need to know and I'll decide what I tell you, or
not.

Regarding your speculation that "with modern regulators, pre-regulation is
not likely to be required.":

"Not Likely" is a very soft qualification in the face of the observed
behaviour of the applications performance during times of over supply. A
100% correlation suggests that it is VERY LIKELY. Statistically
significant, in other words.

**Bullshit. The only time pre-regulation will be required, is for
under-Voltage events. That is easy enough to deal with.

What isn't clear is why my Regs (assuming it is my Regs) misbehave.

**How (precisely) do they "misbehave"?

I have

already conceded that the most cost effective action for me to take would
be to replace the 7815/7915 pair with a new pair that DOES have the 30V
spec. and see what happens.

**HUH? ALL 78XX/79XX regulators are specc'd virtually identically. Except
for a couple of low power variants, all have a 35 Volt maximum Vin limit.
Allhave a 2-2.5 Volt 'drop-out' Voltage. IOW: You should have AT LEAST 18
Volts DC at the regulator input terminal. There is a gotcha here too. You
need to measure the ripple too, as any ripple which has peaks falling below
the 2 - 2.5 Volt limit will impress that ripple on the output. IOW: Measure
the ripple to the input of the regulators.

But I may have to replace all other Regs in the applications power supply,
for the same reason, before I get to the bottom of it. I don't have the
necessary test equipment or the expertise to pre-determine which Regs are
at fault.

**Then you are screwed. You need to perform measurements to determine where
the problem is. I'll betcha it ain't the regulators. Regulators are VERY
reliable. And they all perform pretty much the same, if the have the same
designation.

Apparently AC regulation is a difficult task.

**And a stupid idea.

TXU certainly do it VERY

BADLY.

**TXU?

We're all bored with your top-posting now.

 

[Mark]

Ok, thanks for that. .It's probably bad advice, but thanks for trying.

Yep, Toroidal transformers are trendy ..because they are very popular!

That there are better transformer types (maybe 'Air Core', *groan*) I don't
doubt for one moment, but I assume that there is good reason for the
Toroidal transformer's popularity and it is likely to be cost/effectiveness.

(p.s. Weren't you the guy who WANTED to be excused from giving me 'advice'?
I excused you. Did you change you mind?)

 

[Trevor Wilson]

Ok, thanks for that. .It's probably bad advice, but thanks for trying.

**My advice, bad? Not bloody likely.

Yep, Toroidal transformers are trendy ..because they are very popular!
**Duh.


That there are better transformer types (maybe 'Air Core', *groan*)

**There are APPROPRIATE transformers for each application. Air core
transformers are not seen outside of RF work.

I don't

doubt for one moment, but I assume that there is good reason for the
Toroidal transformer's popularity and it is likely to be
cost/effectiveness.

**Sure. Toroidals have a low radiated hum feild, are (nowadays) cheap to buy
and they're reasonably efficient. However, their downsides make them the
LEAST suitable choice for YOUR specific needs. An EI transformer would be
better, whilst an 'R' core would be better again. It's horses for courses.
You seem to be making a selection based on the simple criteria of: "Oh, it's
what everyone else does." BIG mistake.

(p.s. Weren't you the guy who WANTED to be excused from giving me
'advice'?

**I'm certainly toying with that idea. You appear to be spectacularly
stupid. You have assiduously avoided parting with details of your
application and have refused all attempts at offers of good advice.

I excused you. Did you change you mind?)

**I don't care what YOU did.

 

[Mark]

Oh, you boring little sod. Do I have to explain it all over again.

a) I have already described their misbehaviour to the best of my ability. I
have neither the test equipment or the expertise to give you more
information. If I had that ability, I certainly wouldn't be WASTING MY
FUCKING TIME at 'aus.electronics'.

Some further food for thought, perhaps: Why do those individuals who claim
to have electronics ability [I am not in that group] WASTE THEIR FUCKING
TIME at 'aus.electronics'. Now that is a paradox inside a enigma.

b) Your assumptions about the problem are still the same as before, i.e:

i) that my 7815/7915 pair have that spec.
ii) that my 7815/7915 haven't gone faulty.
iii) that my 7815/7915 are the cause of the observed behaviour.
iv) that ALL the Regs in the application are 7815/7915 types. They aren't.
iv) I can't remember the other thing.

c) I don't know how to measure ripple current and I don't think it can be
done with an ordinary (or garden variety) DMM. I.E. I haven't got the
equipment to do it anyway.

The reference is to TXU Corp. Don't you watch TV?

Huge power supply company in Australia and a huge multinational company. One
of the biggest in the world, I suspect.

It seems somewhat anomalous with your claimed expertise in electronics that
you wouldn't instantly recognise TXU. 'Google-boy' perchance?

 

[Mark]

No. The application's design is not up for discussion or modification.
Replacement of (possibly faulty) component parts is as far as I want to go.

The Black Gates are price/performance competitive. If you pay the RIGHT
price, that is.

"low level audio applications"??? What do you mean? (I think I know what
you have assumed, but I just want to be sure.)

 

[Trevor Wilson]

Oh, you boring little sod. Do I have to explain it all over again.

**Phil is 100% on the money. You're an idiot.

a) I have already described their misbehaviour to the best of my ability.
I have neither the test equipment or the expertise to give you more
information. If I had that ability, I certainly wouldn't be WASTING MY
FUCKING TIME at 'aus.electronics'.

**And NO ONE can help you, unless you provide them with information. You
need to present some measurements.

Some further food for thought, perhaps: Why do those individuals who claim
to have electronics ability [I am not in that group] WASTE THEIR FUCKING
TIME at 'aus.electronics'. Now that is a paradox inside a enigma.

**We share ideas and assist each other.

b) Your assumptions about the problem are still the same as before, i.e:

i) that my 7815/7915 pair have that spec.

**That is a given. ALL 78XX/79XX regulators have the same specs.

ii) that my 7815/7915 haven't gone faulty.

**If they present close to their rated Voltage, under normal conditions,
they're not faulty. IME, 3 terminal regulators either:

* Go open circuit.
* Go short circtui.
* Present significantly lower than the specified Voltage at the output.

Having said all that, they are VERY reliable. VERY, VERY reliable. For two
regulators to go belly-up simultaneously is almost unheard of, unless
something very bad has occured.

iii) that my 7815/7915 are the cause of the observed behaviour.

**What behaviour? Be precise.

iv) that ALL the Regs in the application are 7815/7915 types. They aren't.

**What a surprise. You neglected to provide all the information required.

iv) I can't remember the other thing.

c) I don't know how to measure ripple current and I don't think it can be
done with an ordinary (or garden variety) DMM. I.E. I haven't got the
equipment to do it anyway.

**You need a CRO. You can calculate it. Any good electronics text will
provide the calculations you need. Do you have AT LEAST 18 Volts on the
input of the 7815/7915 regulators?

The reference is to TXU Corp. Don't you watch TV?
**Non-sequitur.


Huge power supply company in Australia and a huge multinational company.
One of the biggest in the world, I suspect.

It seems somewhat anomalous with your claimed expertise in electronics
that you wouldn't instantly recognise TXU. 'Google-boy' perchance?

**Non-sequitur.

 

[Trevor Wilson]

No. The application's design is not up for discussion or modification.
Replacement of (possibly faulty) component parts is as far as I want to
go.

**Were all the caps faulty then?

The Black Gates are price/performance competitive. If you pay the RIGHT
price, that is.

**No. In your OPINION they're good.

"low level audio applications"??? What do you mean? (I think I know what
you have assumed, but I just want to be sure.)

**Line or phono level audio.

 

[Bob Parker]

**Were all the caps faulty then?


**No. In your OPINION they're good.


**Line or phono level audio.

Hey Trevor...
He doesn't know anything about electronics. You're wasting your time
discussing voltage regulators and anything else the slightest bit
technical like oscilloscopes. He's probably had to search the net to
find out what "CRO" means.
I'll just watch and smile as this bizarre thread continues...

 

[Franc Zabkar]

You are assuming that I had a perfect 9 VAC sine wave input to my
application. If I'd had what I wanted, I wouldn't need to ask the question.

What I DO have is an very imperfect NOMINAL 240 VAC, domestic supply, like
everybody else. (actually more imperfect than most, as we live in remote
rural area with many idiosyncrasies in the supply).

I can step down the domestic supply to (nominally) 9 VAC, but it suffers
exactly the same problems as the domestic supply. i.e. the output of the
transformer isn't 9 VAC and isn't a perfect sine wave.

You are missing the point. There is no way that you can get 15VDC from
a 9.00 VAC rms sine wave using only rectification, filtering and
regulation, even under ideal circumstances. Hint: 15 is greater than 9
x sqrt(2) for all possible values of 2.

- Franc Zabkar

 

[Mark]

Duh!

I've NEVER claimed to have any electronics expertise, what-so-ever. Never.

So this would be an oft used Usenet tactic, Vis-à-vis;

a) First, manufacture a claim and then infer that the other combatant made
it.

b) Then others may use that false claim as a justification for further
criticisms, attacks and/or allegations of arrogance, pseudo intellectualism,
whatever. At this point it is open slather.

c) Never-ever concern yourself with the truth of what claims the other
combatant did ACTUALLY make about their expertise or lack of it. This would
be sheer folly and may lead to the loss of the argument.

Regarding your suggested methodology. Making the suggested measurements
reveals nothing unless it is done during periods of voltage overload. So OK,
I could pull the DMM and quietly sit there and wait for a hours, perhaps
days, poised with my probes at exactly the correct location and angle and
just wait for something to happen.

Yes, I could do that, if I was a creation. Well done.

Regarding your assertion that I don't know "how challenging it is to design
and implement what you wanted". Well I certainly don't know how difficult
it is for YOU.

As it happens, I am one of the few contributors here who has ACTUALLY
suggested a viable and cost effective solution to my own request. Go on,
look back. I DARE YOU.

I am not being conceited here, I actually EXPECTED that I could get a better
solution from someone here.

Re: Your analogy. Could I suggest you reproduce it in another post and I
will go over it with you, point-by-point. This post is already approaching
an unmanageable size and in any case your 'analogy' amounts to little more
than 'white noise'.

Re: Bob's advice. It may be good advice. The likelihood of getting any
useable information from a .Usenet thread is inversely proportional to its
length. So the longer this goes on, the more likely it is good advice.

Also, I don't know where you got that 'Pre-amp' presumption. Certainly not
from me.

You reckoned that if I was being honest I would say "Actually, I built the
engine, it's running badly, does anyone want to buy some really good fuel
filters?"

The natural presumption from that statement is, according to you at least,
that I would be dishonest if I claimed:

a) Not to have built it,
b) That it is running well (except during periods of over supply)
c) That I don't want to sell my caps.

However, all those things are true. So that is the first reason why your
analogy is fucked up and arse about.

I made no claim about making it, or designing it for that matter. I did tell
you that I had swapped some capacitors, which is only a minor modification
at best. I was a little surprised that nobody suggested checking for dry
joint(s) on the caps, but hey, that is your prerogative.

Regarding this statement: "I thought my insightful analogy would help you
understand why people responded to you with derision".

I developed my own theory, days ago. Read my functional description of the
supposed club of 'deciders' that I have dubbed 'Phil-o-philes'. My theory
much stronger that yours because, like all good theories, my theory is based
on verifiable, empirical observations of facts. (i.e. when Phil inferred
that the power to "get to decide what others accept or believe" exists as a
right that some people may hold others not. To make such a distinction, he
must believe that the power a) ACTUALLY exits b) is assignable to various
individuals and to the exclusion of others, which is as much as saying, he
believes it exists as a RIGHT. He didn't say on what basis this right might
be bestowed on individuals, but we can only assume it is earned by
displaying superior knowledge or experience.

On the other had, your analogy is based on what? Three complete falsehoods
for a start and then no empirical observations that you have elucidated thus
far.

Your analogy is NOTHING more than OPINION, masquerading as analysis. Perhaps
you may develop it into something more useful, but thus far it has the
appearance of analogy by a 'petrol head', and nothing more.

Regarding your apology: I will give it my consideration.

Well, I didn't think of searching for the '7815 datasheet', so fucking
sue
me.

That shows that you are not experienced in working with electronics -
anybody who regularly does searches for component numbers would
automatically add "datasheet". Furthermore, anyone with electronics
experience would understand the operating characteristics of a common
linear
regulator without needing to refer to a datasheet - it's really common,
basic stuff.

Either way, the cheapest solution is sounding like I should exchange the
7815 /7915 pair, for a pair that DOES have that 30V spec. and in so
doing,
eliminate the possible cause of the observed clipping during voltage
overloads.

The first thing to do is measure voltages at key points - at the output of
the AC plugpack at the input of the regulators, at the output of the
regualtors etc. Boring I know, but that is how you start the diagnosis a
power supply problem. That you don't appear to realise that really basic
fact demonstrates a lack of knowledge and experience with simple power
supplies and suggests that you're not equipped to diagnose nor fix the
problem.

Also, I take umbrage (offence, to you) at your trite analogy. It isn't
an
accurate portrayal of what happened or my actions or my motivations or my
attitude. I would welcome a point-by-point comparison of your analogy and my
behaviour.

My analogy, horribly misspelt as it probably was, was reasonable, if not
as
amusing as I would have liked. You clearly don't get how challenging it is
to design and implement what you wanted - it's *really* complex stuff. By
comparison, getting a standard dual-rail, linear regulator power supply to
behave is trivial.

The more I think about it, Bob's advice is correct - you should get
someone
with a solid background in electronics to fix your preamp for you.

Your PRESUMPTION that I must pay too much for my Black Gates is based on
what? An ASSUMPTION that I pay foolish prices. That is both insulting AND
ignorant (of how cheaply Black Gates can be purchased).

Hey, if they give the sparkling audio performance you like, fair enough. I
probably haven't paid enough attention to the musicality of the caps I
buy.

I also take umberage to your allegation that I am not "being straight-up
with [this group]".

You reckon that if i was being honest I would say "Actually, I built the
engine, it's running badly, does anyone want to buy some really good fuel
filters?" Here is why I wouldn't say such a thing:

a) I didn't build the application, I modified it.

You never said that. It does explain a lot. In my analogy, it would be
like
revealing that you'd modified your engine while at the same time giving
the
strong impression you don't really know how engines work.

b) It isn't running badly (under nominal conditions), it sounds superb.
c) I am not SELLING anything.

That was a joke. Sorry. I was kind of thinking that if your "thing" didn't
end up working, you could recover some cash-money by Ebaying them fancy
caps.

I look forward to our point-by-point comparison of your analogy with my
behaviour. I can't find many comparisons at all. Do you do this often? (that
is: make up stupid analogies that just don't work).

Look, I've got nothing to add. I thought my insightful analogy would help
you understand why people responded to you with derision. Obviously you
still don't get it, and that seems to be because you don't have the
knowledge and experience in electronics to diagnose and solve the fault -
everything you say reinforces that fact.

Get someone who knows what they are doing to look at your device. If it's
a
power supply problem they'll diagnose and fix it very quickly.

And you might be able to pay them in capacitors