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Jeffrey D. Medwin

Has ANYONE read EE John SWENSON, and will YOU ?

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[Moderator Edit: The title, removed reference to specific member in the title. Give the poster, it appeared to be derogatory, with this poster it is better to error on the side of caution until interested parties can provide input to moderators]

 

 

I have something wrong with my Member account, so I can not post photos and files up here. Will talk to Moderators tomorrow , Monday, on that.   [I'm sure there they will all be in line to see who can help you with that first]

 

I just read all the Audio Asylum Power Supply notes, ( which I complied in chronological order  ) written by EE John Swenson, when he was actively and initially  exploring Low DCR and Low Stored Energy Supplies, which he wrote about around 2006     This different type of supply was the brainchild of Dennis Fraker, ( Serious Stereo ) in the late 1980s, when Dennis applied the acronym  LSES.  Dennis is is from Montana, and he has said " I used Cowboy Logic " to develop it !!! 

 

 

 

[removed mention of the guy you mention 10X a day]

 

Thankfully, any interested-in-audio person does not have to be an E.E. to read and to understand John's results at all !!!  .  Swenson was independently exploring and " all over the place " in his experimenting, but in EVERY instance, he found the LSES   ( and his experimental derivatives  ) to

 

a) easily outperform on O-Scopes , etc. and b) sound better .  VERSUS 100 plus years worth of "Traditional Critical Inductance" power supplies - the ones that EEs are taught to rely upon. 

 

If you take the time to read ALL Swenson's posts, you will see the difference, in favor of LSES,  which was STARTLING better - his words, listening-wise , in every iteration and  every experiment he did. 

 

Here is the actual post, from the KLIPSCH FORUM, where YOU can download and read EE John Swenson's results, ( if you care about better audio. )

 

( Also download and read carefully John L. Hasquin, another very sharp audio-orientated  E.E., to read his experiments and views ) 

 

 

https://community.klipsch.com/index.php?/topic/182623-kt88-direct-coupled-design/&do=findComment&comment=2373502

 

 

 

Now, I have a public question to ask [totally inappropriate. You really need to start a Youtube channel, you will make a fortune. This is no longer going to be a platform for you. You are welcome to engage in a respectful manner, but your days as the savior of audio are over here, if you and any your followers (I'm being optimistic on your behalf, but who knows, they may be the great silent majority) are offended by that I'm sure you can find another Forum or platform where you can get your views out there. Heck, if you do, I will even link where they can go to watch videos, listen to podcasts, read a blog, whatever]

 

Q1 ) Did you read it ??  Public answer please.

 

Q2) If you read, just Swenson, HOW could you EVER question me publicly about a LSES power supply??   How?? [Seriously? So you just want to have a public debate, the same one one on every forum you have ever been on? Let me take a stab at an answer, someone with zero technical knowledge: How? Maybe because Swenson comes across as being a big a nut as Jeffrey?

 

 

 

So far, in 16 months since I made that information available here, there seems to have been a total of 6 people in this entire world who have downloaded SWENSON, and 17 people who have downloaded John L. Hasquin's compilations.    No one has ever talked about it, recognized it up here, nor talked to me privately.

 

[That strikes you as odd? Have you ever considered that maybe it is your delivery? Or that anyone your regard as knowledgeable or a good designer is automatically rejected because of the tone and tenor of your posts?]. 

 

                                                                                                             - - - - - - - - -- - - - - - -- - -- - 

 

If any of you want to know why I say what I do ( about [removed, hint, about an amp seller]

 

I am getting tired, mighty tired, of people putting zero effort into things, and not ever understanding what end is up !!  [There just are no words. On second thought, again, have you thought about the delivery. You are the quintessential example of the Dunning Kruger effect "DFE"]

 

[Removed, baiting]

 

The new preamp of mine has a kind of LSES supply, recall..... no choke over 7 Ohms DCR, no cap over 50 uF, .....   all film. 

 

Best to all of you, 'am glad to assist folks with this.  Just do your part.  Learn. [More DFE]

 

Jeff Medwin

 

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14 minutes ago, Jeffrey D. Medwin said:

Simply, for yourself, read John Swenson, then John L. Hasquin, both EEs who actually WORKED on this type of supply !!!  John Swenson did two months worth of PSUD2 computer simulations, before he ever even built the first supply.  Read and learn what these two sharp, open-minded  EEs discovered !!  It all makes sense, it is evident.

 

" All truth passes through three stages.  First, it is ridiculed.  Second, it is violently opposed.  Third it is accepted as being self -evident."  Arthur Schopenhauer.

 

My reading of Maynard's reply to you is that he has already read the documents that you allude to, and that he disagrees with them.

 

By the way, one should not make the logical fallacy of of concluding from Schopenhauer's words that all ideas that are ridiculed are necessarily the truth.

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Posted (edited)
5 hours ago, Jeffrey D. Medwin said:

Why don't you personally find out what the truth really is? 

 

Jeff 

 

You speak as if these guys were like Moses bringing down some sacred scripts from the mountain!  They are just a couple of guys with their own understandings, and maybe sometimes misunderstandings and prejudices too.

 

Those documents you linked to are a bit of an undigested dog's breakfast and I really don't have the patience to sift through all the blah blah blah. One thing did catch my eye, where Mr Hasquin is talking about the merits of using smaller rather than larger capacitors in the power supply.  He says that

 

"In all our engineering books we are taught that a high capacitance power supply is good. The authors imply that the low impedance of the capacitor will be able to deliver current to the output tube quickly and prevent voltage sag. On the surface this looks good on paper. However, it could be more wrong. Once the capacitor has used its low impedance to source current, it then uses that same low impedance to hog any and all available current to regain its charge."

 

(I think he probably meant to say "couldn't be more wrong" when he said "could be more wrong.")  He goes on to say that  "the capacitor will always rob the output tube for available current in order to maintain its charge."

 

It sound like he is probably a bit confused here.  The larger the capacitor, the more steady the supply voltage available to the output tube will be.  In the limiting case where the power supply capacity goes to infinity, the voltage supplied to the output tube will be absolutely rock steady.  (A bit like having a B+ supply coming from a set of car batteries connected in series.) 

 

He goes on to say that "This is why over stuffed power supplies always sound slow. The over stuffed power supply prevents the output tube from reproducing dynamics." 

 

Maybe he is trying to say that he considers it desirable, from an audio point of view, to have a supply voltage that is wobbling around in correlation with the demands placed upon the power supply by the amplifier.  I think I have heard it said sometimes that the kind of "audio expander" effect that one gets with a saggy power supply actually sounds quite lively and dynamic. 

If that is what he is really talking about, and he is really saying that the sagginess of a poorly-regulated power supply is what is desirable, then that is absolutely fine, but it is good to be clear about why he is after the properties whose virtues he is extolling.

 

As always, of course, the discussion of such matters is very different for a class A amplifier and a class B amplifier.  For class B, like a typical push-pull amplifier, the net current demand (averaged over the audio frequency timescales) gets much higher when the music gets loud.  By contrast, in class A (like an SET amplifier), the net current demand (averaged over the audio-frequency timescales) is more or less constant, regardless of whether the music is playing loudly or softly.

 

 

 

 

 

Edited by Backfire

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16 minutes ago, Backfire said:

 

You speak as if these guys were like Moses bringing down some sacred scripts from the mountain!  They are just a couple of guys with their own understandings, and maybe sometimes misunderstandings and prejudices too.

 

Those documents you linked to are a bit of an undigested dog's breakfast and I really don't have the patience to sift through all the blah blah blah. One thing did catch my eye, where Mr Hasquin is talking about the merits of using smaller rather than larger capacitors in the power supply.  He says that

 

"In all our engineering books we are taught that a high capacitance power supply is good. The authors imply that the low impedance of the capacitor will be able to deliver current to the output tube quickly and prevent voltage sag. On the surface this looks good on paper. However, it could be more wrong. Once the capacitor has used its low impedance to source current, it then uses that same low impedance to hog any and all available current to regain its charge."

 

(I think he probably meant to say "couldn't be more wrong" when he said "could be more wrong.")  He goes on to say that  "the capacitor will always rob the output tube for available current in order to maintain its charge."

 

It sound like he is probably a bit confused here.  The larger the capacitor, the more steady the supply voltage available to the output tube will be.  In the limiting case where the power supply capacity goes to infinity, the voltage supplied to the output tube will be absolutely rock steady.  (A bit like having a B+ supply coming from a set of car batteries connected in series.) 

 

He goes on to say that "This is why over stuffed power supplies always sound slow. The over stuffed power supply prevents the output tube from reproducing dynamics." 

 

Maybe he is trying to say that he considers it desirable, from an audio point of view, to have a supply voltage that is wobbling around in correlation with the demands placed upon the power supply by the amplifier.  I think I have heard it said sometimes that the kind of "audio expander" effect that one gets with a saggy power supply actually sounds quite lively and dynamic. 

If that is what he is really talking about, and he is really saying that the sagginess of a poorly-regulated power supply is what is desirable, then that is absolutely fine, but it is good to be clear about why he is after the properties whose virtues he is extolling.

 

As always, of course, the discussion of such matters is very different for a class A amplifier and a class B amplifier.  For class B, like a typical push-pull amplifier, the net current demand (averaged over the audio frequency timescales) gets much higher when the music gets loud.  By contrast, in class A (like an SET amplifier), the net current demand (averaged over the audio-frequency timescales) is more or less constant, regardless of whether the music is playing loudly or softly.

 

 

 

 

 


 

I, and many others, have explained this to Jeffrey countless times on here and on other forums as well.  He has been shown proof that choke input filters with inductance of a fraction of the critical value, and low value caps, function as poorly regulated capacitor input filters which is why it will work to some degree in class A service.  I, and others, do not believe that hum which is evident a few feet from a speaker but not at the farther listening position is acceptable.  If I recall correctly, Jeffrey has said that some hum is needed as a carrier of musical information.  He can correct me if my memory has failed on that point.  I don’t know what else to say......

 

 

Maynard

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25 minutes ago, Jeffrey D. Medwin said:

Thank you !!!!   You will have to spend more time, reading it all, digesting it, ...

 

Honestly, it simply isn't worth the expenditure of time and effort sifting through 25 pages of Hasquin and 37 pages of Swenson to see what might be in there amongst the blah blah blah.  I can already see the gist of the thing; it is not that hard to understand what happens if one uses varying amounts of inductance and capacitance in a power supply.  It is all standard EE understanding.

 

If they are really saying that they just happen to like the various colourations that result from having a bit of hum and a bit of sagging, or whatever, then that is fine.  To each his own...

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3 minutes ago, Jeffrey D. Medwin said:

 

 

Maynard at least, read all the material.  I take his word.  He will just have to live happily with his convictions.  Fine with me. 


 

Just to remind you that I am an ET, not an EE, but I certainly think like one having been instructed by some of the best!  After all these decades in the field I can truly say that they were correct, especially when it comes to audio.

 

 

Maynard

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smilie_b_020.gif

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Jeffery D M.

 

I have to ask, what is this fascination of yours to constantly try and get others to believe / understand your theory of how AUDIO components must be built for better SOUND.  I swear it seems so simple to understand. EVERYONE  AND I MEAN EVERYONE has different hearing. Because you, I, Maynard or anyone else decide amp A is better, CAN NEVER become a FACT. This is all based on subjective hearing. EVERYONE  you ever quote is making a decision / comment  based on there own subjective preferences. 

 

Of course it is more likely you simply enjoy stirring a pot, and seeing what rises.......................On with the show

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14 minutes ago, MicroMara said:

smilie_b_020.gif

Early form of gentleman s disagreement

 

 

 

 

 

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4 minutes ago, billybob said:

Early form of gentleman s disagreement

 

 

 

 

 

A gentleman is a man who can disagree... - Quote

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18 minutes ago, joessportster said:

Of course it is more likely you simply enjoy stirring a pot, and seeing what rises.......................On with the show

Maybe JDM is simply bored today.

 

 I am. Been raining all day and I've nothing better to do than read this thread...... 
 

cincy

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37 minutes ago, Jeffrey D. Medwin said:

 

Yo,

 

Don't follow the thread Matt.  Download JLH and Swenson onto your hard drive, and wade through it all, develop your own opinion, based on their work.  I can always help you, if you have any questions !!

 

Jeff 

Thanks, JDM. I'm not that bored. 
 

cincy, not Matt. 

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9 hours ago, Jeffrey D. Medwin said:

" All truth passes through three stages.  First, it is ridiculed.  Second, it is violently opposed.  Third it is accepted as being self -evident."  Arthur Schopenhauer.

I don't believe he ever said that, I think it was incorrectly attributed to him . Schopenhauer did have a paper that included a statement about truth that was written about 20 years before he was first quoted as saying those words. Schopenhauer did say in a paper something along the lines of  the celebration of truth is short lived and lies between two longs periods where it is considered either paradoxical or trivial.

 

 

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9 hours ago, Jeffrey D. Medwin said:

You have that right.  I logically agree with you. 

 

Since I think you are an E.E., why don't you take the time to read these two fellows experiments, and their conclusions. 

 

Results are likely opposite what you think to be true about power supplies in tube amps !! 

 

Why don't you personally find out what the truth really is?  I am happy to help, already have by compiling their work and posting it to see.  Just click on it, download it, and read it.

 

Jeff 

Why on earth would we want him to to do that here. Why not reference all of that mishmash in the forums where it has been discussed?

 

Are you trying to save these people from themselves again. Didn't I tell you we were not smart enough to figure that out and we are all doomed to trust our own ears and we will simply live with the knowledge that you have found the perfect amp.

 

If Fraker wants to discuss this have him get a website, or you get one for him, and talk about why he does what he does. If anyone cares the can go to his website, or the other Forums where you have brought this up.

 

This thread was clearly started by you to:

 

1. Draw Maynard into some sort of debate, which he wisely begged off, but yet you persist, as you always do;

 

2. To get Fraker's name out there yet again (do you have some sort of financial arrangement with him?);

 

3. To tell everyone on the this Forum that what they have equipment and speaker wise is worth having and we are too dumb to understand what you have discovered?

 

This is HISTORY right here, this is where I, as a Moderator, came to the conclusion that Jeffrey's wealth of knowledge and information is just not worth the excess baggage it comes with, and the time to deal with it. Post away and when I get around do it, it might be a day, a week, or a month, but I will approve your posts if they are polite, respectful and you lose the arrogant, condescending attitude. If they are offensive in any shape for form, I won't approve them. They will sit in the ether.

 

To the Forum Members, especially those that hang out in Talkin' Tubes, I apologize to you if you have been coming here to see what new and exciting things Jeffrey has to advise, inform and educate you on. I know many of you wait here on baited breath to see what audio revelations are in store for you so that you can experience the true audio excellence that only Jeffrey has been capable of achieving. Feel free to PM him so you don't miss out on what he has to teach you about. 

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19 hours ago, Jeffrey D. Medwin said:

If any of you want to know why ....,  you only have to read those compilations, and my consistently HONEST years of amplifier descriptions,  should make total sense to you. 

 

I am getting tired, mighty tired, of people putting zero effort into things, and not ever understanding what end is up !!  

You might want to start with buying some poster board and laying out your plans to see if they will fit in the chassis you have intended before getting half way along, you might not be so tired.

 

I know the feeling, I get tired, oh so tired, of trying to help someone understand how things are coming across. Trying in every way imaginable, privately, with other moderators, with other Forum members, and they can't find their . . . well, suffice to say, they don't even understand what an "end" is, and if you say "up" they say down.

 

Feeling quite lethargic and impecunious right now.

 

 

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2 hours ago, Jeffrey D. Medwin said:

 

Yo,

 

Don't follow the thread Matt.  Download JLH and Swenson onto your hard drive, and wade through it all, develop your own opinion, based on their work.  I can always help you, if you have any questions !!

 

Jeff 

Cincy, IMHO, but YYMV, but IME this will be a total and utter waste of time.

 

Just my two cents.

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3 minutes ago, dwilawyer said:

Cincy, IMHO, but YYMV, but IME this will be a total and utter waste of time.

 

Just my two cents.


LMFAO! 
 

Ya think?

 

cincy

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9 minutes ago, dwilawyer said:

Cincy, IMHO, but YYMV, but IME this will be a total and utter waste of time.

 

Just my two cents.

 

I have the document. I haven't had time to do anything but browse a few pages. But from the limited bit I've seen, these fellows are discussing mainstream EE topics as if they actually understand them. Perhaps the discussion goes off the rails further into the document, I won't know until I read more of it. But in what I have read they simply discuss the fact that some of the textbook EE design practices for power supplies don't work well in amplifiers that have poor PSRR (power supply rejection ratio). Their solutions to the problem may well be very clever and even novel, but they are not magical. And why Mr. Medwin feels the need to equate it to magic is a mystery to me.

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16 minutes ago, Edgar said:

 

I have the document. I haven't had time to do anything but browse a few pages. But from the limited bit I've seen, these fellows are discussing mainstream EE topics as if they actually understand them. Perhaps the discussion goes off the rails further into the document, I won't know until I read more of it. But in what I have read they simply discuss the fact that some of the textbook EE design practices for power supplies don't work well in amplifiers that have poor PSRR (power supply rejection ratio). Their solutions to the problem may well be very clever and even novel, but they are not magical. And why Mr. Medwin feels the need to equate it to magic is a mystery to me.

 

Serious question here Edgar, is any of this worth reading?

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