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A nightmare, actually. In it, my introductory EE class college professor, E P Morris, came down from heaven to visit his graduates. ‘I come to give you a new testament, a new approach to Electrical Engineering’ he said. ‘All that theory and math was bunk. Experimentation is the new approach. All you need is a few low henrys inductors and low valued capacitors, and a few clip leads from Radio Shack’.
Follow Ups:
Down near the bottom of the thread Henry has simulation pictures that show what is really happening with a low L first choke power supply. Its not too damn hard to understand. While Jeff may have not been the best at explaining it, Henry has done a fine job of explaining it.I have a Biomedical Electrical Engineering degree from Purdue University, and the EE in me would never settle for anything other than this low L first choke power supply. With this approach it is easy to reduce the dynamic impedance of the power supply down to around 65 ohms. The conventional choke input power supply that meets critical inductance normally has a dynamic impedance nearing 400 ohms.
Conventional EE thinking says if you want to feed a load, then you want your source impedance to be no more than 1/10 of your load impedance. Which power supply do you, as an EE, think will be a better power source for a 300B amplifier; the 400 ohm, or the 65 ohm one?
Until you have tried one of these power supplies, I don't think you have any grounds to stand on. Jeff's methods are strange, but he did discover something that the old timers had missed. I believe the primary reasons this has gone undiscovered for so long are the following: 1.) No scientific mind would have followed Jeff's methods. 2.) We did not have simulation software like PSUDII in the 1920's. 3.) This is the year 2007, and new discoveries are occuring everyday.
Rgs, JLH
P.S. As a side note, you did know that in the mid 20th century an attempt was made to close the U.S. patent office under the rational that everything that was useful had already been invented and there was no need to keep it open. Mind you, this was before the PC was invented.
"As a side note, you did know that in the mid 20th century an attempt was made to close the U.S. patent office under the rational that everything that was useful had already been invented and there was no need to keep it open. Mind you, this was before the PC was invented."Urban Legend. Sorry. The oft-misquoted speech was from the Commissioner who was asking for the Patent Office to be expanded, certainly not closed.
> Conventional EE thinking says if you want to feed a load, then you want your source impedance to be no more than 1/10 of your load impedance. Which power supply do you, as an EE, think will be a better power source for a 300B amplifier; the 400 ohm, or the 65 ohm one?Jeff isn't the only one experiencing difficulty in the explanation department. The above statement is crudely simplistic, inappropriate for this application, and wholly ignorant of the dynamics of filtering pulsed DC. I've analyzed the low DCR concept in depth, and I think I have a pretty good understanding of how it works. I am not one of its detractors. Nevertheless, it is only one means by which to reach the finish line. These ongoing claims that it represents a sonic/engineering breakthrough are not only contentious and misleading, but may constitute the worst case of narrow-minded wishful thinking that I have seen here in quite some time.
The 'flywheel' supply (will we ever stop putting it in quotes?) that Henry described is not really what Jeff is pushing. Jeff is advocating low L and low C supplies in a general way, as a desirable approach on its own grounds. The supply that Henry described is a specific application that happens to include low L and low C, but also depends on a balance or 'tuning' (sorry, Henry) that needs to be there or the benefits (as identified by Henry) are lost entirely.To get to the point: it's possible that Jeff built a flywheel supply (no quotes!) but it's VERY unlikely. In fact, I found that I can't calculate the odds because my calculator has only 12 digits. Really, the odds that Jeff and Henry are (were) talking about the same thing is astronomically small. Not that either thing isn't interesting on its own, but they're still different things.
To really get to the point for real this time: Henry did not explain in engineering terms why Jeff likes his particular style power supply.
"Henry did not explain in engineering terms why Jeff likes his particular style power supply."Nor would he admit to it, even if he had! ;-)
__________________________________________________
Boo!
Wow, no one can replace Ivan303 !And to set the record straight, Jeff Medwin certainly didn't develop Low C, HY. DCR supplies, Dennis Fraker did so in his first Serious Stereo SE 2A3 amp, prototyped by him, way back in 1992 , and UNchanged since then ! And it certainly uses NO flywheels.
Jeff built that type of Low C, HY, DCR supply in February 2007, with Greg's 245 SE amp in Kansas City, and reported on the supply configuration and our listening results on-Forum, when it blew us both away !!
didn't it go back further than 92? --
Hi Fred,Well, in the 1980s, I can recall Dennis and Dr. Halijak PhD. EE were having custom made 1.0 HY @ 10 ohm chokes made.
I believe he finished his first S.S. SE 2A3 amp in 1992, but Freddie, that was still fifteen years ago.
in anticipation of having my head removed, but here goes:You make some great points, many of which I tend to agree with (those that I understand, at least), but I would like to tweak one just a little.
> > > 1.) No scientific mind would have followed Jeff's methods. < < <
I would say that *some* scientific or researchers of science, would follow his methods, but that *most* engineering minds (the appliers of science) would not have. There are different methods that are available to researchers – it seems that Jeff's are unconventional, perhaps somewhat original, and may be criticised by the general EE community, however, in time the accumulation of practical evidence may support his findings, despite said criticism.
I am interested in these developments and am approaching them with a relatively open mind, however I do recognise that further evidence is required to support Jeff's hypotheses. For me, evidence must include practical application, in a range of amplifiers. Perhaps I will try Jeff’s latest formula for myself…
That said, I may be full-o-cr*p. I am just a 'mature' final year HSc student with a growing interest in medical research and a past life in quality management. My skills may not translate well to this topic; my assumptions may be way off base...
Kind regards
Raymond
Ultra-consumers: Spending money they do not have to buy things they do not need to impress people they do not like.
between those with pioneering spirit and all the rest. I have always thought that curiosity drives all scientific desire/research and action drives all scientific discovery....and invention.Nowhere is this difference more evident than in the so called 'culture war' of contemporary American politics. But I leave that discussion for elsewhere.
I have yet to see any engineering data that actually describes the sonic differences between various tubes.
What measurement describes how/why thoriated tungsten filiments sound differently than nicad?
What data describes the sound of box [shaped] plates compared with cylindrical plates?
What data explains the different sound of graphite plates as opposed to metal?
Same for sonic differences between steel, nickel and nano-glass core materials. What about core geometry?
For these, one must EXPERIENCE the various designs to even know that a difference exists, much less what sounds best. I have seen discussion where, absent this date, some would argue that NO such differences exists. Hmmmm. :)
Any Philo Farnsworths here?
Your audio-specific examples get my point across better than my more general explanations.There is much evidence - ie. consistent outcomes across a range of applications / subjects / environments - that is not necessarily backed by definitive theories. A little research into the mechanisms of action for drug / phyto / nutrition therapies will soon indicate this.
Yes, a plausible or accurate explanation of a mechanism of action is hugely beneficial to improve our understanding and therefore application and further development, but perhaps the most important (or only) 'evidence' are the results of practical application. Perhaps there is some Zen in science.
.
Hi Mikeyb,Think about the very very BEST designers of SE audio amplifiers in the world..... ( I can name more than a handful of individuals )
How many of them were EEs???
It gets really quiet, doesn't it !!
I rest my case.:-)
as to who are the "the very very BEST designers of SE audio amplifiers in the world". Can you provide a list, please?
There IS a place for the EE. I very much doubt that by expermintaion alone an amplifier could be sucessfully designed. Even you have to have a starting point.
Names ? Yes, but off-line, Email me. I have read some of the EE books covering tubes mikeyb.
"Think about the very very BEST designers......"The very very best design engineers don't give a rats ass about audio.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Very true.
...However, they probably don't give a rats ass about SET amps except maybe as an eccentric diversion from the real world.Don't know about you but I'm impressed with the sound of a lot of the SS building blocks out there these days (decent Op amps, AD/DA converters etc). These were not designed by inspired artists.
There was an interesting article in US N&WR about the unhearlded world of analog chips and how TI has remade itself by concentrating on them. Robert Pease was mentioned. I always considered him as one of the best and he has concerned himself with audio at times IIRC.
would be that artists are going to be interested in it.Doesn't matter what sort of Artist, look at the day-jobs of the owners of hot-rods. For most part the good engineers are going to work where the future is percieved to be. Like when the Aero guys went for fixed wing airplanes in the early 20's instead of the Zepplins. That didn't stop a few brilliant folks like Eckner from staying with LTA. But the best were going to be doing work on things like the ME-109, P-38, and the Mosquito.
As for audio, change the specs the industry is working to, and you'll see product delivered to meet it. Want to make a fortune, figure out how to define and measure what makes an amp sound good, and patent the process, then sell it.
Hi.Isn't every designer in the audio industries trying to "define & measure what makes an amp sound good, patent the process & sell it" since day one?
Has many made a fortune this way yet? I can quote someone in this audio industry for decades & patented hundreds of his designs in the US patents office alone. I guess he got to make tones of fortunes.
The problem is sonics is so subjective. You like it doesn't mean they also like it.
I don't think that MPG technology has actually advanced the audio art.It has made it more portable and ubiquitous though.
Questionable goals at best, unquestionably compromised quality throughout.
Assuming you meant MP3 vs MPG: MP3 may not have advanced the audio art WRT to sonic quality at this point in time. Have to admit though, at high bit rates it can be pretty darn good.As you observe, MP3 has indeed made music more portable and "ubiquitous". Much greater variety is easily available too! IMO, these are not questionable goals at all. They are different than those of a sonic purist but are certainly valid and definitely more viable than pure sonics in a fiercely competitive capitalist environment. I view MP3 and the like as a stepping stone to high quality and maybe lossless compression schemes of the near future where all your music needs (and other stuff too) will be supplied digitally via some cheap and fast broadband connection at a quality level YOU select.
These days it seems that some purists have to limit their musical horizons because their reproduction equipment reveals unacceptable flaws in the source material and they can't listen thru it. Too bad for them. I may be dreaming but I believe those days will be behind us soon. Will highest quality audio be mainstream? Probably not but it never was mainstream in the past. Will high quality audio cost more than lower quality? Probably, both in terms of transmission and storage media and of the cost of the material itself. When/if things settle down, everybody will get just what they want.
as you observed, I actually meant MP3.....I was watching 'Debby Does Detroit pt45'.mpg while typing, that's all.As you pointed out, vurtually all audio developments have been driven by market forces in the last 70 years.
By questionable, I would suggest that we don't actually function better in an environment where while shopping for lumber and tools, we have to hear some schlock hit music on the overhead....or in the elevator.
What about all the restaurants that have TVs playing everywhere and a sound system that plays Musak?
I find it interesting that in all the marketing date for the newest best audio development is framed like 'sounds as good as.....vinyl or tubes.'
I don't mean to disregard all technological developments, but simply point out that they DON'T actually constitute a real improvement in actual audio quality....just delivery and marketing. This fact seems to be progressively lost as we readjust our standards and expectations around these developing technologies...and the assumption that newest is implies improvement.
Later
D
You further observed: "I find it interesting that in all the marketing date for the newest best audio development is framed like 'sounds as good as.....vinyl or tubes.'"In my exposure to audio mass marketing the catch phrase is "...sounds as good as CD" This applies to HD (ha!) AM & FM radio, computer sound equipment and portable MP3 players. About my parts, tubes and vinyl are mentioned in nostalgic lapses but almost never in terms of a reference point for audio quality. The phrase "Digitally Remastered" you do hear as well as an occasional reference to the "master tape". Tape? Must be referring to a time before the hard drive became the preferred digital storage medium.
most good recording are still recorded with analogue tape...if not tube equipment. Those recorded directly to digital are not the same quality...yet at least.If you ever get the chance, listen to some master tapes. Sometimes Paul Stubblebine brings some to shows like CES.
I have compared vinyl to digital on an ultra high resolution tube/horn system. The difference was staggering. It's funny how much we 'forget' in audio....assuming we ever knew it in the first place.
I like your comments though, it reminds me of the 'genuine margarine' that I see in the store these days. We used to joke about the term 'genuine plywood' back in the 70s.....:)
With the WEB, we will soon forget that film photographs look different than JPGs too.
Later
D
More ( and likely better ) SE amps get built by EE's than your little group. Do the numbers if you dare.Good Engineering is art. There is no other way to describe it. Your claim that only artists can build a good amp is just plain ignorant.
Hasn't been my experience at all.But I do see EEs devising CHEAPER ways to make amps....just not better. Been that way since the days of Bell Labs and WE. Those guys designed with no limits and all efforts of EEs since have been to make audio accessible to larger portions of the population through things like miniaturization and economy.
Better audio quality has NEVER been the goal of the engineers since.
The EE's are not at fault. Nor are the scientists. Engineers in all professions are tasked by their managers to innovate for competitive advantage only. The competitive advantage is demanded by the Sales and Marketing Staffs who must have some some way to bludgeon the customer's purchasing department, or the final consumer, who have both been sold on the idea that "cheaper is better". For the EE there is rarely enough time to pursue the limits of measurement analysis, looking for meaning in the grass of the spectrum analysis plot in front of him. Rarely will his engineering manager allow any sort of exploration into territories where mathematical analysis is less than bullet proof. All because that manager has to have performance metrics with which he can wrest a budget large enough to allow enough engineering hours just to do the minimum.... make it cheaper.You need only look at the path of Mackie Designs to see the difference between a visionary owner asking "why not?" and a corporate owner shouting "do not". Bell Labs and WE were one of the few instances where "why not" was the motto, in the engineering and science labs and, most importantly, in the rest of the corporate structure and final consumers.
Somewhere, it seems, that we lost an understanding of the *sharing* of music, well recorded and reproduced at home, can bring to our lives and others.We have been sold and marketeered a paradigm of excessive consumption: miniaturisation, 'improved' pseudo-convenience, fashionable (faddish) appearance, product churn-over. Music, and the equipment that replays it, has been turned into a fast-moving consumer item - appears temporarily fashionable / 'best', but is ultimately unsatisfying. Buy another - got to keep with the fashion / have the best. This is happening at the MP3 end of the market and in high-end audio (facilitated in part by the magazines). We temporarily satisfy short-term desires (thank you instant debt) only to suffer long-term dissatisfaction. Good for business and the economy though - keeps the ca$h, er debt, flowing.
Yes quality means different things to different people - from a (very basic) business POV, it is consistently meeting, perhaps exceeding, the needs and wants of customers. Problem is, the needs and wants of customers are so manipulated by sales and marketeers that we may have forgotten what is fundamentally important. Note: not all sales and marketing people do this!
As for 'best' engineers moving to the cutting edge etc, as discussed in other posts, there are many reasons why people do what they do - it does not just come down to technical ability. Money, family commitments, morals, ethics, health, lifestyle, and opportunity (there are many more). Some of the ‘best’ (whatever that means) will not be at the cutting edge; some of those who are not the best will be at the cutting edge. For moral and health reasons, I turned my back on what many would say was a great career – at the cutting edge, of sorts, to become a student - ideals and practicality need not be mutually exclusive... I digress; sorry.
.
By and large, engineers are paid to design what 'the market' wants, which, unfortunately, is generally small and cheap. Except for TVs, of course, where bigger is better. 5 foot screens - what for???I do design my own tube audio gear for home use, so here the orientation (quality) is more important than price (within reason). Quality is, admittedly, a loose term, subject to wide interpretation. I have my own set of priorities, which include aesthetics as well as sound. Hence the reluctance to use an open frame 'pole pig' style power transformer and cheap open frame chokes.
Dave, you wrote:
Better audio quality has NEVER been the goal of the engineers since.You seem to differentiate between EE's hired to design audio and EE's doing it for themselves. Do you think there are no EE's building valve amps? I meant to refer to EE's building their own, and not industry led folks.
I do like your ref to WE/Bell and their results obtained( by EE's ) when operating with few financial constraints. These gentlemen were working on discovering the best audio. Do you really think that any sort of positive reputation would have been bestowed on them if they hired unskilled laborors?
Ultimately it's all about working to spec and budget. I know what my spec is, and it seems to be rather expensive( and heavy ) to achieve. I think the fault you describe is of the consumer and not the engineers. They're just following orders; they don't have any knowlege of the direction their work is actually taking us.
Hi.Given same conditions, whoever got more technical insight of the relevant disciplines should do a better job, artists or EE regardless.
Knowledge always helps. An artist can self-learn good tube knowledge to build a good sound amp without EE training.
in discussing this at present is we are thinking in arbitrary absolutes: EE vs. artisan. Thing is, to design and build a functioning SE amp one needs some degree of EE's knowledge. Conversely, EEs also need some degree of the artistic when making subjective decisions. These two broad dimensions will vary in strength and balance in each person.Examples:
Jeff & Dennis have read some texts though perhaps do not have the understanding required to consider and implement certain options the EEs may. OTOH, perhaps Jeff & Dennis have enough knowledge to design and builds a competent amp and then without the constraint of 'accepted approach' and through some creative experimentation have discovered an alternative approach to some aspects of design. They are still refining their approaches and can not fully explain them, yet they have been found to offer some promise...
that it sometimes pays to try different color line cords?
and there were not a great variety of line cord colors available. But I would hazard a guess that he would have prefered orange, being a very brite professor.
eminating from those holes in pnp transistors???? What about the effects of Alpha particles on three toed, punce breasted tooney tangagers?
"I take you as you are
And make of you what I will,
Skunk-bear, carcajou, bloodthirsty
Non-survivor.
Lord, let me die but not die out." THE LAST WOLVERINE by James Dickey
but in it Fred Terman came down from heaven and asked:"The transistor was invented in 1947, why are you still messing about with TUBES?"
.
those g-damned thevenin black box theorems, promise of universal crappy 731 opamp and subsequent CD were nuff to wish for a savior...
I've got several colors of them. Low Hy inductors are also good for LC filtered low voltage supplies. They like lots of C though.
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