Power supplies are equal in importance to amplifier circuits
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I’ve been designing electronic circuits for 50 years. It took nearly half that number of years for me to finally come to grips with the importance of power supplies in circuits.
In my earlier days, I thought of power supplies like most engineers: necessary add-ons to the all-important bit that handles signal. All that was needed was to keep them adequate in terms of current and voltage delivery, clean, regulated, and low noise. The important parts, the circuitry that mattered, was separate.
Knowledge and hubris are powerful cocktails that keep us from learning. I needed to pull my head out of the expert’s books and venture into the wild unknown where discovery and progress are made.
Here’s the thing. Power supplies and signal circuitry are part of a system in the same way your heart and arteries work together: separate, yet each inexorably tied to the other.
The problem for engineers to grasp this concept is made difficult because of the way we see schematics. A typical schematic separates the power supply from the signal circuitry, thus encouraging engineers to ignore them as a system. Take a look at this schematic as an example.
What you’re seeing is the signal schematic. Note the power supply isn’t even shown. Rather, it’s implied with a simple +/-63 volt indication on the far right. If we had the complete schematic we’d have a second page that showed the power supply as a separate and (almost) unrelated diagram. In reality, they are not separated, just like my example of your circulatory plumbing.
When we look at the power supply and amplifier as a unit we suddenly realize the amplifier is a mere extension of the power supply, not the other way around. The valves (be they transistors or tubes) control the flow of what the power supply is capable of delivering. Here, power supply speed, current, transient response, wire or circuit trace impedance, energy storage and recovery, and grounding issues all play into the quality of what we hear.
So, the answer of whether or not power supplies matter as much as circuitry is a simple yes. Hell yes!
For most of the last 20 years I’ve used amplifiers that are defined by the power supply, all switch mode, Primare’s UFPD, Linn’s Chakra and Devialet’s PFC power supply. So I guess they’re important.
Since, in my youth, I enjoyed designing linear power supplies and devoted a lot of effort to it, I am very sympathetic to Paul’s proposition. I would tend to disagree with him on a technicality. The function of a PS is to provide a constant unvarying voltage up to a rated current for other electronic circuits. That is not always easy, but if you have a design which achieves that goal it can be used for many amp designs which have similar requirements.
The PS design is not always independent of the amp it is supplying. Obviously it has to provide the right voltage and current, but you can design further for the particular amp being supplied. Overcurrent detection can be used to protect the PS itself, but it can be modified to suit the requirements of the amp, which may need foldback or shutdown to shield it. The old quasi-complementary class AB amps could profit from a ramped voltage at turn-on to reduce speaker thump. Non-bridged class D amps are sensitive to speaker crossover energy being pumped back into the power rails and need circuitry to compensate for this, This is normally done in the amp itself but functionally it is part of the PS regulation. These are instances where the PS and the amp need to be considered as a whole.
Where I differ from Paul is that I think you need to devote more work to the amp design than to that of the PS to get a good sound. I completely agree with him that, without very effective regulation which matches the needs of the amp, the sound will suffer. Also, to touch on a bete noir of mine, if the regulation is good then you will not need any of that pesky power conditioning.
Chris, you make a very good point, and it goes beyond amplifiers. I had a PS Audio DAC and one of its features was the complex power supply. I replaced it with a British designed DAC with a similar complex power supply.
As to incoming power, my unit’s blurb says: “Power supply is unaffected by the mains … It is universal and compliant with all power grid supplies: 90-240Vac – 50/60Hz. … is automatically protected from anomalies including surges, dips and overloads. On a practical level, functional range is stretched out even further to 50 – 270Vac ~ 40/70 Hz, making … anywhere in the world.” The power supply is by far the largest component in the whole system – the Class A amplifier it feeds is the size of an SD card. Moreover, the power supply was designed by someone in and for the benefit of the telecoms industry, before moving to the audio industry. As a non-expert consumer, I would expect an audio device requiring mains power to function optimally and provide the level of protection required when plugged into the wall. I assume the reason why most devices don’t is cost.
I have a ripping server made by a computer company that came with a smps. When I suggested getting an external lpsu they laughed and said it would be a complete waste of money.
Obviously views vary inside and outside the industry as to what is needed for optimal performance.
I am a believer!
A few months ago, the power supply went out on our mixing console. Out tech replaced a big capacitor in the power supply and the new sound was stunning… stunningly quiet. I don’t remember the console being this quiet in 20 years… the day we installed it.
There are always places we look to get clearer sound. Always obstacles we’re looking to jump over and hoops to go through to get better sound. Most of the time it has to do with “power” .
Good post, Paul! Completely agree.
Cookie Marenco
Blue Coast Music
https://bluecoastmusic.com/
A large electrolytic capacitor or bank of capacitors may be a great ripple filter at 60 hz but not very good at much higher frequencies. The fix is cheap and easy. Just shunt them with a small value capacitor in parallel and it will take out any higher frequency parasitic noises the electrolytics don’t.
Thank you for your response. Not sure if we’re talking about the same thing, though.. this isn’t an amp, it powers our mixing console. There wasn’t a 60 cycle issue (we solve those long ago at the power outlet). But hey, I’m not a tech… I can put you in touch with our tech and he can tell you what it was.. I can tell you it was big and expensive and worked better than what was there before. 🙂
Cookie
Parasitic higher frequency noise can be a problem that large electrolytic capacitors can’t solve. This simple and inexpensive addition could solve those problems. Just saying.
In most of the sites frequented by DIYs there is the criterion stated by you as a certain fact.
But one day I consulted on this topic, (wanting to incorporate in my MC-2300 small by-pass capacitors in parallel with the main caps) with the Engineering Department of McIntosh Laboratory, which we all know are in the amplifier business since the year 1948, and the Head of Design told me that if they had found any improvement with the use of By-pass caps, they would have incorporated them a long time ago. (My MC-2300 came from the factory with 4 caps of 39,000 uF, and so they continue on the recommendation of the manufacturer)
I understand that the manufacturer has a complete audio laboratory to make such a statement. Considering how expensive the devices of this factory are, I do not think that the marginal price increase due to the use of the By-pass Caps could be significant, if when incorporating them, they would have verified a decisive improvement.
I do not believe that the DIYs have the necessary technical means for deeper investigations on this subject, other than their ears, which turns the matter into a sobjectivity.
I consider that this is a case similar to the controversy of using in the different audio circuits, the so-called boutique caps. (ultra expensive)
Well, this is just my experience, since I do not design amplifiers.
First of all I’m a degreed electrical engineer. Second, I’ve encountered this problem in the field. Third, this kind of noise only becomes a problem under certain circumstances and that may not be very often but when it does it can be maddening to fix if you don’t know how. I didn’t get this solution off a DIY site.
You are agreeing with McIntosh’s engineers.
Using them autoformers, surely these by-pass are not necessary because those, act as Hi frequency natural filters.
I have not said at any time that you have obtained the information on the DIYs sites, I have only suggested that you and they agree on this point, which is true.
Something you may want to consider … If your console is indeed 20 years old, you are probably still working with an analogue power supply. It might make sense to update it to a Switch Mode Power Supply.
The advantages are many but the two biggest ones are very tightly regulated voltages and absolutely zero 60 or 120hz hum.
I totally agree with this. I’m fortunate enough to have a friend that makes he own line of stereo equipment. He has constantly tweaked the power supplies in his gear. I listen to the changes as he makes them in his home system. Every power supply change yields noticeable improvements.
The other aspect regarding power supplies is that changing to an external power supply always seems to yield improvements. I currently have my friends amp and preamp. Both the preamp and amp were single units that were later modified to have outboard power supplies. The preamp was first, which yielded great results. The amp was changed as an experiment I instigated. After the preamp, I wondered why amps don’t have outboard power supplies. It looks a bit odd, but it sounds great. I’m not sure if the improvement comes from physical separation, or the fact that the extra space an external power supply affords allows for a more beefy makeup. Most likely both. I’m surprised an external power supply isn’t more mainstream in high end audio.
A good portion of my entire 50 year career starting from my first job has been devoted to power supplies of many types and power distribution. I have spent more tens of millions of dollars of other peoples’ money on them than I can count. I design and build these systems for industrial applications. Mostly I design around already manufactured products although on rare occasions I’ve designed them myself. I also figure out problems and design flaws in these systems and fix them…. if they can be fixed. Otherwise they have to be replaced. But my knowledge only goes up to 15,000 volts. If it were up to 500,000 volts I could get an excellent paying job anywhere in the United States and start work tomorrow.
Of all the industrial and scientific instruments I’ve designed power supply systems for, none of them required a power conditioner of the type a power regenerator supplies to home audio equipment. They all functioned perfectly with the power supplies built into them. That is the job of their power supplies, to solve the problems based on their design and compensate for the anomalies utility power can have that plagues some consumer audio equipment. Power supplies should probably be the most expensive part of high end audio electronics systems. When that equipment costs in the hundreds of dollars you can understand some of the short cuts and inadequacies of them. But when they are in the thousands, tens of thousands, and even hundreds of thousands of dollars, there is no excuse for their inadequacies. Not only should they be able to solve every problem a power regenerator solves, there are other problems they should be able to deal with as well. That they don’t shows one reason why high end consumer audio electronics is a poor value for money. It’s not just power amplifiers, it’s all of the electronics in a high end consumer audio product.
The power supplies themselves are not rocket science. But in complex power distribution networks including utility power distribution networks and mission critical networks that cannot be allowed to fail they can be extremely difficult to analyze and the flaws can be very arcane.
https://www.youtube.com/watch?v=slDAvewWfrA
“But my knowledge only goes up to 15,000 volts”.
LOL. Outstanding. Where else could you find this stuff – except on the world wide web?
I can’t believe that Paul’s willing to devote some his precious time to this endeavor, knowing what kinds of examples of, uh, genius he’s likely to encounter.
“Knowledge and hubris are powerful cocktails that keep us from learning.” Good line Paul. I might add the word “prior” just before knowledge since new learnings become knowledge. Great blog.
Any electrical engineer who isn’t running constantly scared does not have enough knowledge to realize how many variables there are he doesn’t know about that can kill him. After the smoke clears, everyone is an expert and knows exactly where the engineer blundered. There’s probably still argument of how and why the FIU walkway bridge in Florida collapsed.
I wonder if signal circuits are ever grounded in some some fashion within the components or are they always floated to avoid ground loops.
Last year I installed an 800 amp 50 volt GE Tyco Telephone DC power plant. It had three grounds. An NEC AC safety ground, a gigantic DC signal ground, and a DC frame ground.
Common sense dictates that the audio circuitry should be isolated from the power line for the reason you cite… ground loops. For this reason the power supply includes transformer isolation that allows the device’s internal DC ground to float.
However; within a well designed device you will find both signal and DC grounds that often cover more than half of the area of the circuit boards. You will also find RF grounds in sensitive areas where capacitors and ferite beads block EMF from entering circuit inputs.
When you connect two devices together the floating grounds are joined by the cables, ensuring that all the system’s grounds are at the same potentials.
For highly sensitive devices like turntables there is often a separate grounding lead that ensures the turntable and it’s amplifiers share a common ground with the AC ground in their power cords.
So, it’s pretty safe to say that grounding and bypassing are pretty much a done deal … at least in the good quality stuff.
A small correction…
“…ensures the turntable and it’s amplifiers share…”
Should be:
“…ensures the turntable and it’s amplifiers chassis share…”
My bad … sorry.
You take, for example, a $1,500 PS Audio S300 stereo amplifier, and plug it into a $10,000 PS Audio P20 Power Regenerator. The big power plant will make an immediately noticeable improvement to the sound. To my mind, this is no biggie. Yet there are those who use observations such as that as support for an argument that the power supply in the S300 must therefore be inadequate in some way, and that the design of the product must be flawed. Well, duuuh, of course it’s flawed. That power supply is designed to a budget. If Paul had approached the design of the S300 with a flawless power supply, it would be twenty times the price, size and weight (but still with the amplifier circuitry of a $1,500 amp).
Yet the same considerations apply to my own BHK300 monoblocks, at a higher price point. The big power regenerator (in my case, a P10) still makes a big enough difference that I would not be willing to live without it. Has Paul dropped the ball on the design of the power supply in the BHK300? Hell no … even at a retail price of $7,500 each the big monoblocks are still built to a budget. I’m sure Paul would tell you he could design a flawless power supply for the BHK’s amplifier circuit, but the price, size, and weight would balloon astronomically.
I don’t understand why this comes as a surprise to people.
My own experience leads me to believe that very effective regulation, to the point of isolating the DC rails from all but the most extreme mains variations, is achievable without massive cost. However that experience was over 40 years ago, so I am not going to go all didactic about it 🙂
… which begs the question, if you are after an S300 at peak performance, are you in for $11,500?
That may actually be the reality. As you are of course well aware, the leading UK brand Naim, with annual sales of around $40 million, pretty much packages external power supplies with all of their products although they are priced and sold as individual components (and sometimes as a pair). The power supply is usually around 30-40% of the total cost.
You do get horrendous box-counts and a large bill. A dozen boxes is not unusual. This system doesn’t even have a turntable, phono stage or power supply for the phono amp.
https://www.stereophile.com/content/naims-wall-oamplifiers
Well, the S300’s amplifier circuit, powered by a hypothetical $10,000 power supply will definitely sound a lot better than the stock S300. On the other hand, it won’t sound nearly as good as the stock BHK250 at $7,500. That’s the key design goal … to get the best possible overall performance for the price point at which the product will sit.
Naim have been producing separate, upgradable power supplies for as long as I can remember (going back to the early 1980’s). Regardless of the bulletproof rationality of this approach, it is one with which consumers remain persistently uncomfortable. Which is why so few other companies have followed Naim’s lead.
I’d love for Paul to comment directly on this … but he’s on vacation 🙂
Naim is the bread and butter revenue for many UK dealers, but they seem to have a lot of reluctant brand-loyal customers. On my first audio buying trip in 12 years in 2010 I went to a West End dealer and was first offered a rack of Naim boxes. No thanks. Teddy Pardo bought a Naim system 30 years ago and replaced it by building his own units. It performs much the same, if not better, but much lighter on the bank account. He now has a factory and an international business and lots of ex-Naim customers.
I had a Naim 32/250 combo back in the 1980’s, and it was a pretty serious piece of kit, although it didn’t look the part at all. Even at that time, Naim offered a couple of optional external power supplies for the NAP32 (the NAPS and the SNAPS). Both seemed absurdly expensive for an add-on power supply. I was intrigued enough by reports of how good they were that I built my own external power supply using a module from a Maplin catalog. It did make enough of a difference that I used it for as long as I kept the Naim.
The other interesting thing I did with the Naim was to replace its built-in power cord with solid copper mains ‘flex’, soldered directly to the transformer terminals. I was really amazed at the difference that made.
You couldn’t do that now as Maplin went bust 6 months ago. Not enough demand for DIY power supplies, or DIY anything really.
I hope your 32/250 had chrome bumpers. I love ’em. Best, possibly only, good thing about Naim. Dead cool in my book.
Whilst tripping down memory lane, here’s a Naim beater that is still in service in my house. It’s over 30 years old, the best of the super-integrated brought out in direct competition and after a full re-cap and upgrade by Colin Wonfor a couple of years ago it’s like new. Note the ELNA smoothing capacitors.
https://flic.kr/p/NDthJK
https://flic.kr/p/2b1YXU4
I always liked the DYMO tape labelling of the phono switches on the base plate. There was always one inaccessible switch.
Here’s a review for those who don’t know how good this is.
https://zstereo.co.uk/2013/03/28/inca-tech-claymore/
The designer was a power supply specialist, did them for Naim, NASA, lots of audio companies, and of course the famous 300w Class A solid state SECA.
http://photobucket.com/gallery/user/colinwonfor1/media/bWVkaWFJZDoxNDc5MDc3NTE=/?ref=
Oddly enough, I’ve never heard of the INCA amp.
But for stories of the weird and unexpected, you have to get up early to beat this one. There came a time when my Naim 250 died, and I sent it off for a repair estimate. While it was away I needed something else to power my system. I tried a few big name and highly recommended candidates but none of them would float my boat.
As a matter of desperation my friend Richard suggested I try his ancient 1960’s Leak Stereo 30 Plus, one of the first transistor amps on the UK market. It was an integrated amplifier, and all the internal boards were on plug-in cards, including the preamplifier stage. I pulled out the pre-amp card and hard-wired one pair of input jacks directly to the power amp card. To my utter astonishment, this bizarre amplifier, driven by the Naim 32, came closer to the Naim 250 than anything else I tried. It was stunningly close, in fact.
As it happened, the estimate for repairs to the Naim were astronomical, and I decided to pass on it. I think they just wanted to sell me a new unit at only a modest discount. I kept the Leak in my system for a good 2 years before replacing it with a Mission 777 BU (“BU” stood for Beefed Up, as in the power supply). I came to realize that was a mistake, as the Leak actually sounded better.
Now, 30 years later, and well into its 6th decade, the Leak is still doing sterling service in Richard’s house, powering the speakers of his Roland electric piano.
Naim’s loss and your gain. You look in their boxes and you seem to be paying mostly for fresh air. The Inca Tech restore, fix and upgrade cost £125 delivered.
We’re talking 1985 here, and to the best of my recollection, a new NAP250 would sell for £750, and I was quoted £425 to repair my broken (~1978) unit, which may or may not have kept the original low-quality case and connectors at a time when current new products had been substantially upgraded in those two areas.
I’ve been designing electronics for nearly 30 years, repairing stuff even longer and the one thing I’ve always noticed is exactly what Paul has said… Power supplies are an afterthought, not an integral part of the overall system. In fact, most design testing is done with highly stabilised “bench supplies” external to the device and then a quicky draw-up is done for a permanent supply once the device is working as expected. Then it becomes the service tech’s job to fix the resulting hassles caused by under-designed and often inadequate power.
I could probably write a book “Adventures In Rectification” for all the problems power supplies have caused me over the years. But, to make a long story short, I’ve been messing with these little Class D “Chip Amps” from China of late and I have to say that I am completely blown away by the sound quality. But It’s not just the chips themselves that are a big improvement. It is also the move to external power supplies, most often in the form of SMPS “bricks” similar to the chargers for laptop computers (in fact some are the chargers for laptop computers). These little bricks were probably originally adopted for cheapness sake but they also get all the messy AC stuff out of the amplifier’s casing and provide a very tightly regulated DC supply that is refreshed and adjusted in microseconds as opposed to the standard analog power supply’s tens of milliseconds. This purity of power, I’m convinced, makes as much difference as the advances in technology in the audio chips themselves.
I will happily second Paul’s notion that power supplies are just as important as amplifier circuits … perhaps even more so. Even the very best designs and manufacturing will fail if it’s connected to a crappy power supply.
State of the art electronic instrumentation doesn’t require special power conditioning equipment to function properly. That level of filtering and regulation is built into the equipment. It has to be. I’ve successfully designed hundreds of laboratories for everything from electron microscopes and machines that photograph atoms to machines that analyze DNA. Sometimes we use UPSs to prevent corruption of data if there is a power outage but never to condition inadequate AC power from the utility. That is the job of the equipment designer. An aftermarket patch for these problems is usually expensive, often ineffective, and the need for one reflects the inadequacy of the equipment designer unless cost was a factor. In mass market audio equipment it is a factor but in what is purported to be state of the art equipment that costs many times what mass market equipment does the fact that it benefits from improvement by a power regenerator in my mind automatically disqualifies it as a good choice. If it has shortcomings there, then there are likely other shortcomings elsewhere.
While I do take your point, what I was saying is that the !entire power supply! in these little amps is external to the amplifier’s casings.
This is the one I’ve been playing with lately…
https://www.amazon.ca/dp/B07DKZ4RTW
I wasn’t promoting external power conditioners. In fact I agree with you that unless there’s something horridly wrong with the local AC supply, the need for a power conditioner likely does point to inadequacies in the device’s internal supply.
I guess Paul’s philosophy is that, if the purpose of the local AC supply is to power a washing machine, fridge, and TV set (which it is) then it can suffer from all sorts of maladies without being considered to have gone “horribly wrong”, whereas if its role is to power a high-end audio system then a far higher standard of performance is required.
I’d be intrigued if you were to take one of my BHK300s apart (well, perhaps ‘intrigued’ is not actually the right word …) and point out the “inadequacies in its internal supply”. Then we can both sit back and listen for differences when we play it with and without my P10 power conditioner in circuit … 🙂
“I’d be intrigued if you were to take one of my BHK300s apart (well, perhaps ‘intrigued’ is not actually the right word …) ”
Unless you knew me, I’d expect the word to be “Horrified”. (LOL) But the truth is that I have done such tasks in the past. Mostly in line of repair work. From what I know of Paul, I wouldn’t expect to find very much wrong at all. He seems pretty meticulous to me.
With and without the power conditioning would be a perfect A-B test and I would suggest that if you haven’t already you could do that anytime, simply for your own edification.
Believe me, I have most certainly done that. Paul had provided me with a pair of BHK300s to use at the Montreal HiFi show back in 2016. He also sent up a P10 to use with them. After the show, I schlepped them back to my place with a view to auditioning the BHK300s for use in my own reference system.
Initially, I thought I would pass on them because I wasn’t getting as much from them as I was expecting. I hadn’t planned to consider the P10 because I felt where I lived (out in the sticks) I had pretty clean mains power. But it was sitting there glowering at me, so I inserted it in the system. It made a quite astonishing improvement. In fact, it made such a difference I kept both the monoblocks and the P10.
By way of a comparison, I also tried using the P10 with my previous power amp (Classe 2300) and it made a serious improvement to the performance of that as well (but not nearly enough to bring it up to the BHK300 class).
And, just to really mind-f*%$ with you, I sit both my BHK300s and my P10 on individual inflated inner tubes as a crude (but ideal) form of isolation suspension, and this alone has contributed a noticeable refinement in the area of imaging and “air”. Yes, even on the P10. Go figure.
Well, shucks … I’ve heard stuff like this before and it really does mess with my head sometimes.
But I believe the BHKs have tubes, which can be microphonic and vibration damping could actually make quite a difference. Tap one of the tubes with a non-metalic stick while it’s operating and I bet you get a “boing” sound out of your speaker… it’s a common problem with tubes. So your discovery actually does make sense.
Although I won’t dispute it, I’m still a little surprised that a power conditioner would make that much of a difference with a basically ok AC service.
I’ll bet PS Audio would send you a Power Conditioner on a sale-or-return basis. But I don’t recommend you do that unless you would be willing to go through with the purchase. Because, I’m telling you, once you put one in your system for a few days you’ll not be able to live without it … 🙂
They probably would but then I’d end up with something I can’t afford right now. 😉
But I have not seen any test data on an amplifier or other audio component of before and after a PS Power Plant. All the reports are subjective after a purchase.
Are we saying these effects are not measurable? And I don’t mean the scope inside the power plant. The question is not if the Power Plant produces a near perfect low distortion sine wave. I believe it does. The question is if that makes any measurable difference in the operating points of the connected product and if so, how much based on existing power source distortion.
Reminds me of the time many many years ago when I finally could afford a good hi-fi system. But then I realized that most tube amps. were gone replaced by transistor amps the sound of which at that time was nothing to write home about. The bass was prominent mids were sucked out and the highs were brittle and not musical at all. So I decide to make my own amp. It was based on a Mullard circuit with a builtin passive tone control. Boy ! was it good sounding. Then I added a preamp to it and the sound became lifeless. After scratching my head for a while I added a separate power supply to the preamp and the sound became glorious as before in fact better and I had much more control over the sound since the questionable purist approach of no tone controls and balance control were not in existence. That was when I realized the importance of adequate power supply. The power supply should never run out of steam and should be capable of instantaneous response. Excellent bit of information you have supplied. Regards.
Paul, while I agree with your idea that power supplies are just as important as the circuit they are powering, I do not agree with your use of the word “engineer” in you comments.
Take the word “engineer” and replace that with “weekend electronics hobbyist” or ” service technician” and it will then be an accurate representation of today’s subject.
An educated EE most certainly understands the importance or lack there of in some cases of the power supply. That schematic you show is from a service manual. It does not show all the current nodes for one example which a competent EE would take into consideration with the design.
Please don’t assume because you found the importance of power supplies by accident at 25 years into your career, that formal training does not teach this within the first four years. This is the whole point of formal education, be it self researched or by instruction. Where doesn’t really matter much anymore. In fact today with the internet anyone can become a pretty good EE just from self study if so motivated. But 30 years ago we didn’t have that option.
To summarize, today’s post once again suggests the professional engineering community is lacking competence in certain areas but PS Audio knows better. That is not the case. Again the I said the EE community as a whole. There is incompetence in any field and electrical engineering is no exception either.
Not to challenge your statement, because it is largely true …
A good technician has two jobs … 1) To find and replace faulty parts and 2) to try to ensure that repeated failures do not happen. That second goal amounts to “Continuously second guessing both engineering and production departments” and some are pretty darned good at it. Many of the best product improvements to the stuff I worked on were in fact suggested by service techs.
Absolutely. I have worked with technicians by title that can run circles around Phd EE’s. Hence my point that education need not come from university experience. The knowledge is out there especially today. And that is just recently proven by Apple and Google eliminating the college degree requirements. They don’t care where you learned it as long as you know it, that’s what counts for them.
My only problem with the opening post is that it infers EE’s don’t understand power supply importance. Some don’t, but most competent practicing EE’s do.
I don’t think that’s what Paul intended. I think he meant to convey that since power supply design quickly becomes a repetitive task many engineers tend to downplay it’s importance. “I’ve already designed that”…
I didn’t see him challenging competence… more like questioning priorities.
Why is it that machines that photograph individual atoms, machines that verify the potency and purity of drugs meet the standards of the FDA, electron microscopes that magnify to 100,000 power and more don’t need any external power conditioning equipment except for UPSs to be certain they don’t shut down at an inopportune moment but home hi fi amplifiers and other audio electronic equipment do? What do the manufacturers of scientific instruments know how to do that hi fi equipment amplifiers don’t? The answer is that they know how to design power supplies that effectively deal with the anomalies they will encounter and perform to the satisfaction of world class scientists and government authorities who demand equipment approved to be able to certify compliance with laws and regulations. For cheap equipment that would be okay but for very expensive equipment there is no excuse. If a power regenerator improves performance then the designer of the equipment did not do his job as well as he should have. That goes for all of them no matter who or where they are.
Well, lets start by being sure you aren’t comparing apples to oranges…
What types circuitry are we talking about here … the amplifier, at some point, has to be analog… Is your scientific stuff digital or analog?
Now what kinds of power supplies are we discussing … Most of today’s audio gear is still using linear supplies … how about your test equipment analog or SMPS?
What kinds of loads do your gear present that might be different than an audio amplifier with it’s massive swings in current and frequency?
Is there any difference in power delivered to commercial sites from that doled out domestically?
These instruments were available before the digital era. Imagine the degree of precision and accuracy they had to perform to. Variations in voltage or current due to nearby industrial loads, not residential loads couldn’t affect them. Some like early electron microscopes needed rooms that were shielded both electrically and magnetically, two entirely different problems. They had to sit on ground that was completely stable. Imagine what a seismometer has to do to detect tiny earth tremors on the other side of the world to the degree that scientists can tell if it was an earthquake or a nuclear explosion. Think of the instruments used to measure and photograph images of electrons colliding in a cyclotron. Images that had to be synchronized to a millionth of a second like this one in 1945.
https://www.youtube.com/watch?v=KQp1ox-SdRI
First, let me point out that I’m not entirely sold on power regenerators in audio applications. I am however not going to close my mind to the possibility until I see some kind of conclusive proof one way or the other.
I have no doubt your scientific instruments were top notch for their time, but I do hope you appreciate that the power grid was a lot different back then too. It wasn’t being used for NOPL (Network Over Power Lines) or for VLWR (Very Long Wave Radio) transmission, for example.
Things have changed rather a lot since then. So even if only by passage of time you are still at risk of comparing apples to oranges.
I do know two things …
1) SMPS supplies are, in general, far more immune to crap on power lines than analog supplies will ever be.
2) Power regeneration may well be needed in some areas where industrial equipment is messing up the power lines.
Do I think I need it? No. My gear is neither of a power or type where I would expect to find any great improvement.
Do I think those who do find a benefit are playing with self-deception? Maybe.
Is there some snake oil being sold here? Probably.
There is the myth that Shunyata built and sold net filtering devices for medical gear before they entered the hi end market. https://shunyata.com/about-us/
If you scroll down to the bottom and look at the two sets of cardiac traces, then look at the legend in the gray area on the left very carefully, you will see that the traces on the left do NOT correlate to the traces on the right.
Personally I think the traces on the left were made just when the guy had a heart attack and the traces on the right was the residual noise after he was dead 🙂
No, it’s the other way around. They started in high end audio and branched into medical – so they claim. Some very well compensated doctor used Shunyata stuff at home and invited them into a lab off hours to test their power conditioning products in the lab gear. The results they post are of curse not calibrated as always so it’s useless data.
Furthermore these products display no visible safety certifications. Shyunyata claims they are certified but remain unmarked and claimed generic certifications not qualified – tell us the file numbers which are public information. I have asked twice and received in medical facilities with patient attached equipment is absurd. It would not be allowed. The insurance implications are enormous.
Also Shunyata frequently posts fraudulent demonstrations. In a recent test he shoes how his power cords have more instantaneous current delivery than a stock commodity power cord. Yes, he shows a test and we can see the results in his favor. But if you look closer you will see that the stock power cord is 18ga and his power cord is at least 14ga. That is a rigged test. of course a heavier gauge power cord will test with more instantaneous current delivery capabilities. Lets see the test with his power cord against a Home depot Extension cord of thew same length!
I have always assumed a Power Amp is a power supply, with it reference around zero until the dynamic reference was applied i.e. the audio or any phase , frequency and amplitude signal.
My first big PSU designs were large battery chargers for BT, only 100KAmps at 55V but with a crap capacitive load and huge dynamic load changes. My earliest designs were fitted in Harrier Jump Jet and powered the 400V 2A and lower voltage UHF and VHF transceivers, now they were dynamic, running in Class C and nasty aerial loads and being shot at, not good for a PSU.
Then on to SMPSU and specializing in CUK converters. Have a fun read, nightmare maths,
https://en.wikipedia.org/wiki/%C4%86uk_converter
So I love PSU’s and smoke and big bangs. Fun days. So small amp designs of a few hundred watts are not a problem, but getting them to sound right is bloody hard. Now semi retired I have time maybe to write a fun book about them, after the gardening and decorating my wife forces me to do for food, he he sorry M.