Is it possible for a power supply to affect sound quality?

[John Dyson]

9 minutes ago, sandyk said:

 John

It is easily demonstrated by both measurements and using a C.R.O. that a simple  PSU like the OP posted, even with a LM317 voltage regulator following it, is incapable of rejecting HF rubbish such as the harmonics from an SMPS and is grossly inadequate for the best performance from a Digital front end, or even an Analogue Preamplifier , and more so the RIAA Phono Preamp for the TT in the photo ,

even though it MAY be satisfactory for the output stage of an amplifier.

 

Regards

Alex

If the LM317 isn't the right component -- then a good engineer works around the problems, or uses a different technique/technology.  It is about understanding the entire design.  I think that too much of the 'modular' approach is sometimes used, but without understanding the details.

As I matured, I got to the point where I studied everything -- ad nauseum, and it does take alots of  work, more hours and doing the job correctly.  A 'genius' designer who knocks something off quickly might make the beancounters happy, and boost certain egos, but it isn't necessarily good engineering.

This is why I don't call myself an engineer any more -- that is very different than just being a designer.   In a way, a designer is just doing a design, an engineer is producing an engineering solution.  Apparently, there is too little *engineering solution* going on.  It appears that the audio realm has a lot less discipline than building buildings -- must fit together and work properly the first time, or lots of troubles.  I am too out of practice, and I have been undisciplined in my project -- however still making some progress.  A real product would be more engineered and less an artistic exploit.

 

Nowadays, the unhappy consumer must complete the job?  Not good.

 

ADD-ON:  too many prototypes being sold as product?

 

John

 

[sandyk]

3 minutes ago, StephenJK said:

The one thing that would be difficult to identify would be Jax - one of our Maine Coon cats.  Poor little guy just got diabetes and is having a hard time getting around, but he does love his tunes.

 

 That I can relate to, as my 18yo female cat also has Diabetes, and now a thyroid condition needing medication, as well as Arthritis  which responded well to Grainfree with Salmon, Whitefish and Olive oil.(Fish Oil also assists people like myself with Arthritis too.)

 Fortunately she loves this food. Royal Canin  Veterinary Diet  - Diabetic -Feline which may be worth asking your Vet. about.

[StephenJK]

9 minutes ago, John Dyson said:

If the LM317 isn't the right component -- then a good engineer works around the problems, or uses a different technique/technology.  It is about understanding the entire design.  I think that too much of the 'modular' approach is sometimes used, but without understanding the details.

As I matured, I got to the point where I studied everything -- ad nauseum, and it does take alots of  work, more hours and doing the job correctly.  A 'genius' designer who knocks something off quickly might make the beancounters happy, and boost certain egos, but it isn't necessarily good engineering.

This is why I don't call myself an engineer any more -- that is very different than just being a designer.   In a way, a designer is just doing a design, an engineer is producing an engineering solution.  Apparently, there is too little *engineering solution* going on.  It appears that the audio realm has a lot less discipline than building buildings -- must fit together and work properly the first time, or lots of troubles.  I am too out of practice, and I have been undisciplined in my project -- however still making some progress.  A real product would be more engineered and less an artistic exploit.

 

Nowadays, the unhappy consumer must complete the job?  Not good.

 

ADD-ON:  too many prototypes being sold as product?

 

John

 

John,

 

Always appreciate your thoughts.  My father was a Mining Engineer and retired as a Mine Manager.  The most telling point that he ever said and that I remember is that "An engineer is someone who can do for 10 cents that anyone else can do for a dollar".

 

Know your materials, do your calculations, extrapolate a finite lifespan, determine a cost and then work out a build plan.  A designer essentially can be the same person without the legal liability.

 

Stephen

[StephenJK]

3 minutes ago, sandyk said:

 

 That I can relate to, as my 18yo female cat also has Diabetes, and now a thyroid condition needing medication, as well as Arthritis  which responded well to Grainfree with Salmon, Whitefish and Olive oil.(Fish Oil also assists people like myself with Arthritis too.)

 Fortunately she loves this food. Royal Canin  Veterinary Diet  - Diabetic -Feline which may be worth asking your Vet. about.

Alex,

 

Max and Jax have been on a raw meat diet since about a year old.  Pork tenderloin and chicken breast, cut and frozen with Performatrin Ultra can in the mornings to make up for what not eating a mouse doesn't provide.  Maybe we should start a thread about suitable diets for cats?

 

Be well,

 

Stephen

[Abtr]

On 6/20/2020 at 10:39 PM, John Dyson said:

...

The other thing is the resistance/impedance/shielding of whatever connecting wire that you use.   When in doubt, use an RF choke at junctions from the outside world into a box.  Whatever impedance problems there will be will likely be soaked up by some hopefully already built-in capacitance between the power leads inside the design getting the power.

...

Hi John. Do you mean by RF chokes those ferrite beads that can be clipped on DC power cables? Thanks.

[John Dyson]

3 minutes ago, Abtr said:

Hi John. Do you mean by RF chokes those ferrite beads that can be clipped on DC power cables? Thanks.

There are RF chokes like that -- and when in doubt, if you think that there might be a problem, try them, they should seldom hurt.   If I was worried about infiltration through the mains (or those little DC power things), then I'd try a choke, just making sure that there are no unforseen side 'defects'. :-).

 

If there are 'boxes' on each side of a power wire, then it might not just be raw DC or LF AC, so be well informed about using a choke on those kinds of things.  However, if it is a box with a power connector on the other side of the wire, then place the RF choke a short distance from the box.  Don't place the choke 'too close', but a short distance (I don't know how many inches, but about 3" might be good.)  I am thinking about the effects that the ferrite might have on the internals of a circuit, that is the reason for the very MICRO amounts of caution.

 

Gotta look at circuitry as a whole, and not just a mix of components.  This is the reason why I am careful about prescription, and welcome corrections.

 

John

 

[Abtr]

18 hours ago, John Dyson said:

...

However, if it is a box with a power connector on the other side of the wire, then place the RF choke a short distance from the box.  Don't place the choke 'too close', but a short distance (I don't know how many inches, but about 3" might be good.)

...

 

Thanks for the info  I understand a choke must be placed a short distance from the power supply box, but many power supplies have a choke clipped on the power cable close to the box it is feeding DC. Or they may use two chokes, one at a short distance to each box. What are your thoughts on that?    

[Speedskater]

any AC power line filter should be placed as close to the component that it's powering as practicable.

[John Dyson]

1 hour ago, Speedskater said:

any AC power line filter should be placed as close to the component that it's powering as practicable.

Assuming product quality isn't perfect, and is the reason why noise suppression might be helpful -- it might be a good thing to put a slight distance between the device and the suppression filter (ferrite) -- just because the equipment is probably not well shielded.

 

I think that 'close' is good, but 'up against' might possibly cause some change in behavior.   I'd suggest a few inches, but not much more.

 

John

 

[Speedskater]

From reading Henry Ott, my take is zero distance is best.

[StephenJK]

19 minutes ago, Speedskater said:

From reading Henry Ott, my take is zero distance is best.

Gentlemen,

 

I think we're talking about two different things.  A ferrite bead is a passive device installed on the outside of an interconnect and that will absorb RF interference.

 

A choke, or choke coil is part of an active RC circuit generally used in power supplies.

[sandyk]

1 hour ago, StephenJK said:

Gentlemen,

 

I think we're talking about two different things.  A ferrite bead is a passive device installed on the outside of an interconnect and that will absorb RF interference.

 

A choke, or choke coil is part of an active RC circuit generally used in power supplies.

A ferrite bead is normally used internally with several turns of wire through it to make a small R.F. choke, or slip on a component's wire or a link, to reduce RF emission or even prevent R.F. oscillation.
 A Ferrite core (or sleeve) is normally in the shape of a clip on device used on A.C. mains leads, some USB cables such as Printer cables etc. 

[StephenJK]

2 hours ago, sandyk said:

A ferrite bead is normally used internally with several turns of wire through it to make a small R.F. choke, or slip on a component's wire or a link, to reduce RF emission or even prevent R.F. oscillation.
 A Ferrite core (or sleeve) is normally in the shape of a clip on device used on A.C. mains leads, some USB cables such as Printer cables etc. 

I'm guessing pedantic is your middle name. 

 

Whether ferrite core or bead for RF filtering, there is also a choke coil as part of an RC network to filter the output of a power supply.

 

Edit:  It took some doing, as I've never done it before, but i managed to add you to something called an ignore list.  

 

Ah.  Peace, blissful silence. 

 

The birds twittering, the chipmunks chirping, not a care in the world.  

 

 

[manueljenkin]

A couple of doubts to Stephen JK and and Jonh Dyson.

 

Isn't a choke actually an R-L circuit (something like what is used in tube lights starters).

 

I have doubts about using ferrite beads/chokes in power lines. While they can help limit high frequency signals and hence hf noise, won't they also slow down the transients of power delivery. Considering transistors power consumption cycle is complicated, I do expect it to change the performance a little.

[sandyk]

Quote

14 minutes ago, manueljenkin said:

Isn't a choke actually an R-L circuit (something like what is used in tube lights starters).

 

 

 

Chokes are used as part of the Power Factor Correction in Fluorescent lighting, most valve amplifiers for filtering the H.T. supply , and some very low noise Linear PSU designs such as the low noise +5V PSU by John Swenson.

[fas42]

The whole business of setting up a power supply which always works as intended, with added filtering to ensure that mains noise can't impact circuitry being fed by that supply, is complex ... full stop! Arbitrarily "adding bits" in the hope that this will magically make things better is as good as heading down to the local casino, and trying your luck, 🙂. The more one understands what actually occurs, or can occur, with a supply the better the chance of getting it right, when one modifies the circuits - with current components on the market, even budget active speakers make it audibly obvious that doing one's homework makes a huge difference to the SQ - as I'm currently finding out.

[John Dyson]

7 hours ago, Speedskater said:

From reading Henry Ott, my take is zero distance is best.

Depends on the circuitry and physical layouts.  A general prescription isn't wise or possible.   There are REAL reasons for the conservativism in my suggestion...   3" isn't enough to leak very much except in extreme cases, and the possiblility of causing problems with a typical ham-handed design (not resulting from actual engineering) forcing my conservative suggestion.

 

John

 

[John Dyson]

1 hour ago, manueljenkin said:

A couple of doubts to Stephen JK and and Jonh Dyson.

 

Isn't a choke actually an R-L circuit (something like what is used in tube lights starters).

 

I have doubts about using ferrite beads/chokes in power lines. While they can help limit high frequency signals and hence hf noise, won't they also slow down the transients of power delivery. Considering transistors power consumption cycle is complicated, I do expect it to change the performance a little.

Transients on power delivery are complex -- this is why I suggest using good designs instead of nailing on extra fixes.  Prescribing quick fixes necessitate compromise.   Engineering solutions (proper design, shielded transformers where noise is important,etc) allow more precise mitigation of problems.   Buying junk hardware designs (instead of engineered designs) isn't the fault of the customer -- there is a lot of real work in a REAL design, not just focused on the lowest en/in of the input component and the specific circuit for a fancy MM preamp.  Packaging isn't just an industrial arts exercise, but there are real engineering considerations.  It is really difficult for a designer being oh-so-proud of an optimized 'circuit', not taking a few short cuts because they didn't spend the many 100's of hours on 'unimportant' or 'peripheral' issues.  All of their time is spent on their 'circuit'.  (I just got bit by not adequately looking at the whole picture, needing to add 352/384k to my project.)

 

* Can you imagine the problems that we resolved when in the 1970s tech, transmitting lots of data between buildings in the UofI campus at Champaign/Urbana -- lots of thunder storms?   There is a LOT to well condsidered design -- I cannot second guess someone who is proud of a super low noise preamp actually considering the 'unimportant' electromagnetic issues...

 

When I make suggestions, they don't result from any one design being used, but need to consider some really crazy stuff, including worrying about instabilities in feedback loops, strange locations of other inductors/components.  I even consider HW that isn't EMI/EMC rules compliant when I make suggestions.

 

John

 

[Clockmeister]

Gents interesting reading the cut and thrust of this debate, can see a lot of skepticism and arguments for defence M' lud

 

Correct addressing of all the possible issues that effect incoming domestic ac power, common mode noise, harmonic content up to the fiftieth from the fundamental here in the UK that is 50Hz so 2.5Khz plus the usual dc offset we have here over the pond

We have double your ac voltage but only half the current but the emf is greater.

 

The use of full line filters  with both  common mode and differenical choke selections for the application involved. Further dc line filtration after the rectification and main reservoir capacitors before regulation etc.

 

For example our lab reference bench power supplies have around 350uv ripple noise which is pretty respectably quiet.

 

Now if i take said lab psu inside my listening room and hook it up to my uptone ethernet regulator there is a very positive outcome on the sound, said item uses a continuous  650ma during normal operation. However the lab supply is somewhat larger and a great deal heavier than a great many components in my system and it's not easy on the eye either.

 

Some observations I have made regarding a fair amount of digital audio equipment that utilises off board dc power supplies over the years is that the better quality (cleaner lower measurable line noise) the the dc power being supplied, the benefits to the sound quality are generally positive.

 

Power line ac noise measurements are relatively easy to analyse now especially with CE conformity for the EEC directives Cisper 16/20 cover most power supplies for domestic use. This spans from 9Khz to 30Mhz for both conducted and radiated emc emissions plus immunity testing where rf energy is injected into the products to test the surseptability of outside rf/emc possibly effecting the device.

 

A while ago to identify wherther a so called low noise power supply can actually any effect on the device it is plugged into came up with a relatively simple solution.

 

Taking aside we have taken benchmark reading of ac noise via a power analyser (single phase for domestic use) or quality scope with enough sample rate and memory, using a high voltage active differenical probe across the incoming ac live and neutral and a suitable current probe 1ma resolution will suffice. You can also correlate this against the DC output ripple noise on the scope at the same speed indentifying any electrical noise in the house is pretty straight forward.

 

The crux then,  actually measuring the line ripple noise at the point of entry on the device that uses said supply while it is operating in it's normal state will give real world figures of how a power supply behaves under every day operating conditions.

 

So comparing power supplies empirically / subjectively can be cross referenced against actual palpable repeatable accurate measurements and any conclusions drawn can be significantly more enlightened

 

Accuracy of test equipment is paramount here, for myself the findings on this subject are very interesting.  As you are measuring the whole transmission line (impedance pathway) from the psu and connecting cable to the point of connection at the DUT (device under test which may be a dac or uptone regen unit)

 

Also I see a lot if companies claiming quite absurd noise figures for their power supplies like 2nv line noise. Maybe the LT3045  specification is this figure, however by the time you have parallel enough of these up to give a reasonable current rating and sufficient heat dissipation mounting planes and supply vers and supporting circuitry  decoupling and capacitive  storage.  By the time it emerges at the real world end the figure shall we say is somewhat different!

 

 

 

[John Dyson]

1 minute ago, Clockmeister said:

Gents interesting reading the cut and thrust of this debate, can see a lot of skepticism and arguments for defence M' lud

 

Correct addressing of all the possible issues that effect incoming domestic ac power, common mode noise, harmonic content up to the fiftieth from the fundamental here in the UK that is 50Hz so 2.5Khz plus the usual dc offset we have here over the pond

We have double your ac voltage but only half the current but the emf is greater.

 

The use of full line filters  with both  common mode and differenical choke selections for the application involved. Further dc line filtration after the rectification and main reservoir capacitors before regulation etc.

 

For example our lab reference bench power supplies have around 350uv ripple noise which is pretty respectably quiet.

 

Now if i take said lab psu inside my listening room and hook it up to my uptone ethernet regulator there is a very positive outcome on the sound, said item uses a continuous  650ma during normal operation. However the lab supply is somewhat larger and a great deal heavier than a great many components in my system and it's not easy on the eye either.

 

Some observations I have made regarding a fair amount of digital audio equipment that utilises off board dc power supplies overvthe years is that the better quality (cleaner lower measurable line noise) the the dc power being supplied, the benefits to the sound quality are generally positive.

 

Power line ac noise measurements are relatively easy to analyse now especially with CE conformity for the EEC directives Cisper 16/20 cover most power supplies for domestic use. This spans from 9Khz to 30Mhz for both conducted and radiated emc emissions plus immunity testing where rf energy is injected into the products to test the surseptability of outside rf/emc possibly effecting the device.

 

A while ago to identify wherther a so called low noise power supply can actually any effect on the device it is plugged into came up with a relatively simple solution.

 

Taking aside we have taken benchmark reading of ac noise via a power analyser (single phase for domestic use) or quality scope with enough sample rate and memory, using a high voltage active differenical probe across the incoming ac live and neutral and a suitable current probe 1ma resolution will suffice. You can also correlate this against the DC output ripple noise on the scope at the same speed indentifying any electrical house is pretty straight forward

 

The crux then,  actually measuring the line ripple noise at the point of entry on the device that uses said supply while it is operating in it's normal state will give real world figures of how a power supply behaves under every day operating conditions.

 

So comparing power supplies empirically / subjectively can be cross referenced against actual palpable repeatable accurate measurements and any conclusions drawn can be significantly more enlightened

 

Accuracy of test equipment is paramount here, for myself the findings on this subject are very interesting.  As you are measuring the whole transmission line (impedance pathway) from the psu and connecting cable to the point of connection at the DUT (device under test which may be a dac or uptime regen unit)

 

Also I see a lot if companies claiming quite absurd noise figures for their power supplies like 2nv line noise. Maybe the LT3045  specification is this figure, however by the time you have parallel enough of these up to give a reasonable current rating and sufficient heat dissipation mounting planes and supply vers and supporting circuitry  decoupling and capacitive  storage.  By the time it emerges at the real world end the figure shall we say is somewhat different!

 

 

 

I think that you are reflecting an understanding about the real world.   Real design of actually robust equipment (not 'gear') is a lot of extra work.   I have spent many hours playing with really fancy and high performing design concepts -- but reality 'bites'.   Even when you overcome the precision of the simulations, then we all have the real world issues.   I grew up in the 1970s',  in an area where a nearby 170MHz TV station made building home hobby circuits for 100MHz (at a nice output power, mind you) somewhat more tricky than if I lived in an RF clean zone.   I am definitely an RF skeptic, but also a circuit realist.  I can still hear the 'buzz' of the TV transmission in my head -- or is it tinnitus? :-).

 

By the time that a 'tested' circuit approaches the real world, then lots of bad things can happen.  One can do an 'engineered' design, and mitigate by far most of the problems, at the initial expense of wisely spending more time/resources.   Of course, if not doing 'engineering' we have the problem of hacking on special solutions is worse.  Also, finally, the 'designer' (not engineer)  can also just 'sell' something, leaving it to the consumer to do the last steps of 'design'.

 

Being responsible for what is going on will make you even more paranoid and careful than I am now, because the responsibility of engineered design isn't in my lap anymore.  I try to learn from my mistakes (and my colleagues mistakes) as much as possible.  Frankly, I do not like to do rework -- even though it is a fact of life.

 

When I make suggestions, no one can guarantee a total solution, but as step in the process.  First, something to clamp on, next perhaps a filter, next a good isolation transformer.   Depending on the problem, even those 'add ons' won't necessarily fix it.   However, if done correctly to begin with, the circuitry (engineered design) would be a little more robust.

 

John

 

[Clockmeister]

Hello John

 

I would agree a lot of designers do not necessarily take into account the whole picture when putting together their new concepts

 

For myself experiance, a good grounding a few electrical disciplines, quality test equipment and understanding its benefits and limitations as well as the ability to recognise when you need to re evaluate the design for silly items that you would have not thought relevant for that application.

 

For example the Chord Hugo 2 has a smps which is rated at 4 amps ffs I mean it's a dac lol not a small electric fire! The amount of processing power those PFGA's have plus the number of them. The bloody thing idles at 1.8 amps really. The amount of radiated rf is easily measurable with some near field probes.

 

However I firmly believe that with audio the power supply is responsible for around 75% of the total performance of the the equipment possibly more in some cases.

 

SMPS are used simply as they are cheap they deliver more power per size in a smaller form factor than a linear one, but do not think they are the pinnacle of low noise.

[John Dyson]

5 hours ago, Clockmeister said:

Hello John

 

I would agree a lot of designers do not necessarily take into account the whole picture when putting together their new concepts

 

For myself experiance, a good grounding a few electrical disciplines, quality test equipment and understanding its benefits and limitations as well as the ability to recognise when you need to re evaluate the design for silly items that you would have not thought relevant for that application.

 

For example the Chord Hugo 2 has a smps which is rated at 4 amps ffs I mean it's a dac lol not a small electric fire! The amount of processing power those PFGA's have plus the number of them. The bloody thing idles at 1.8 amps really. The amount of radiated rf is easily measurable with some near field probes.

 

However I firmly believe that with audio the power supply is responsible for around 75% of the total performance of the the equipment possibly more in some cases.

 

SMPS are used simply as they are cheap they deliver more power per size in a smaller form factor than a linear one, but do not think they are the pinnacle of low noise.

When I was doing real engineering design back in the past, I would not have even considered using an SMPS for anything but a power amp level of demand.  I was developing FCC compilant SMPS back in the 70s, and frankly, I do not like them for low noise work.  Never really had troubles, but know the problems.   SMPS are a fact of life nowadays, but 'there be dragons'.  My last involevment with SMPS in an engineering setting would be the early 1990s, after which, because of project needs, I graduated totally to software instead of being 1/3 HW at the time.  I did more design troubleshooting/solving the problems left over from circuit designers at time (at all levels, including low noise, high speed, etc.)  Even in the early 2000's, when I went to work every week or so, there'd be a stack of serious, unfixable SW/HW mix design problems, and there can be some really, really strange problems.   The same was true through much of my SW career -- solve the troubles created by missing the 'big picture'.

 

I ended up being more of a systems engineer in the middle of my career -- pulling the disciplines together (e.g. video, satellite, studio, customer premesis,  even some really strange areas, like trying to find a lauch vehicle.)  I knew enough to be able to pull things together -- but, then I guess the testosterone decreases, so the desire to 'work really hard' also does :-).

 

My guess is that a lot of circuit designers depend on a 'brick' doing 1/2 their power engineering/design, but as a lot of audio consumers REALLY using the equipment realize, it is more complicated than 'just sending power to the device'.

 

So, you might see my skepticism when I hear of a sole designer, and maybe someone helping them with packaging, is proud of a circuit, and sells a design based on it.  There is a heck of a lot more to a project than 'make it work'.   I have had lots of broken designs in my lap, where the testers bounce a product, and the developers couldn't figure out what was wrong.  It happens all of the time, but without a good support system, then even a genius circuit designer is little more solid than an experienced hobbyist.  "Make it broke' is an important part of the product creation  process -- and I highly respect those people who find bugs/errors in products also.

 

John

 

[Clockmeister]

Hi John

 

No listen Skepticism is very healthy if we did not have this trait then I feel the human race as a whole would be worse off. We need it like checks and balances it keeps us on our toes!.

 

The only caveat I would say is one can be too skeptical and close minded on occasions and sometimes this can cloud our judgement, I am guilty of this now and again especially when I see ludicrous figures banded about that either mean next to nothing and are used a 'chaffing' exercise to divert you form the real issue at hand. Or just a plain pile  of male bovine excretion.

 

The key here as you have pointed on above is about real world experience you know what you were taught at Uni first principles in the lecture theater are a little difference in the real  world. The point you graduate is the point you really start to LEARN what happens after the party is over!

 

In the real world it is mix of basic principles, long term experience with the subject matter at hand with the ability to actually understand what is happening inside the circuit and its connection to the outside world both signal and power.

 

LT Spice and its ilk are very useful modelling tools that can really help designers and engineers, however it fgives a good picture but not the whole one. Modelling transmission lines from start to end  then actually measuring and de embedding both test rig and paraphernalia is an skill on its own.

 

In recent years I have found TDR (Time domain reflectometry)  to be invaluable tool in the designs I work on for high speed digital serial communications, clock circuitry and  power supply modeling both for SMPS and linear as well as the usual measurement suites of power analysis, serial data investigation options (jitter/Eye diagrams/Histograms etc) However these will point you in the right direction, what you do with the data is another matter!

[andrewinukm]

SJK, you seems like a person with sufficient technical expertise.

Instead of demanding others to supply you or anyone with proof, why not build the power supplies and test + listen for yourself? Then discuss your results with the community. I believe this would bring more value to yourself and this discussion.

 

Many of the people above have built or developed various power supplies, measured them, and listened to them... and have thus formed the their opinions. We are all here by our own volition, no one is obliged to provide anyone with free information or proof, but they did out of love of the hobby/industry. So the question one needs to ask himself is: what value am I bringing to this discussion?

[StephenJK]

3 hours ago, andrewinukm said:

SJK, you seems like a person with sufficient technical expertise.

Instead of demanding others to supply you or anyone with proof, why not build the power supplies and test + listen for yourself? Then discuss your results with the community. I believe this would bring more value to yourself and this discussion.

 

Many of the people above have built or developed various power supplies, measured them, and listened to them... and have thus formed the their opinions. We are all here by our own volition, no one is obliged to provide anyone with free information or proof, but they did out of love of the hobby/industry. So the question one needs to ask himself is: what value am I bringing to this discussion?

You can be as insulting as you like, it makes little difference to me and unfortunately is becoming only too common here. 

 

Disagree with someone?  Insult them.  It's cheap and it's poorly done.  

 

As I mentioned to others, my bona fides and experience with design/build of anything was never intended to be a topic of discussion and won't be.  Case closed, because it just doesn't matter.

 

If you, and so many others actually went back and read the OP, it was with a detailed and specific focus on outboard linear power supplies only, not that you seem to know or care. 

 

And, how any linear power supply based on an old school breadboard diode/filter network could or would compare to some overpriced boutique variation that does the same thing for tens or hundreds the cost. 

 

And, because this is supposedly an audiophile forum, and not an Electrical Engineering association, how that could possibly affect the sound.

 

The fact that some decided to migrate into software modelling and switch mode power supplies has nothing to do with the original topic.  

 

Stick to the topic, or start one of your own choice.  

 

Cheap shots, ignorant remarks - too much of that here lately.