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In Reply to: RE: learn to ignore and move on... posted by drlowmu on March 18, 2012 at 10:14:01
Theorists? I have more project construction under my belt both as a hobbiest and professional prototypes then you can imagine.
You just throw these wild claims out there and hope they stick.
This bantering is getting old. I suggest that you guys kiss and make up, duel it out, move in together, or something. I want to learn about electronics. How to fix and design amps and such wonderful things. So many times I get on here and end up wasting so much time sifting through all the opinions and personal uselessness that I end up learning very little.
When someone has to tell me how smart they are to belittle the other person, then all their credibility goes down the crapper. I don't care what title you carry, where you went to school, who you know, who was your mentor.......means nothing to me.
Education degrees are nice, but when you have to flaunt them it just tells me that you have closed your mind and are decidedly unteachable. I see it happen all the time and when the person is challenged it ultimately results in name calling. That's childish behaviour that's abused by out-of-touch politicians. You don't have my vote.
If someone has an idea that's unconventional then let's give it a try and if it ultimately doesn't work out, then we can move on. It seems that some people have built this power supply that Jeff promotes and it works well for them in their application(s). People have heard the 2A3 amp that Willie Rivers built using this power supply and have liked it. To say it does not work when it has been proven to work is ignorant thinking. You ignore that there have been successes using the low DCR PS.
Now is it your cup of tea sonically? Maybe not. I'd like to try it out and see if it works for me. If it doesn't, then I can move on with conventional builds.
Don't try to police everyone from trying something different just because it does not line up with how things are normally taught. Let people learn how to walk on their own. If they fall down, they'll learn to quit doing the things which cause them to fall. If Jeff is wrong, then word will get out. If you disagree, fine, then state your disagreement, but don't post a page of stuff I have to sift through to learn anything. Like I said, other people have built this PS and it worked well for them. This gives Jeff more credibility than all the nay-sayers.
No one is past the learning stage (unless you're dead). There's always more to learn no matter how much you know, so let's keep this forum at a mature level.
What I'd like to see is Jeff & gusser plus others get together for a blind listening session with six or so different SE amps with neither of them knowing what equipment was playing. Having 2 or 3 of the amps employing the low DCR PS. That would possibly settle the matter for a while. It all may be a matter of what it is we like to hear in our music.
When I was a kid, I used to enjoy making things. For much of my early boyhood I was very interested in model airplanes. I was always working on one plane or another, and it was very frustrating to me that I didn't have the experience or skill to make them come out perfectly like the ones in the magazines. I used to dream about building perfect model airplanes.
When I got to be ten or eleven, I got interested in electronics. My mother enrolled me in a ham radio class at the JCC, and I got my Novice license when I was twelve. I had to work hard to learn the theory and rules, and especially, Morse code.
Around this time I got interested in stereos. My father had a Pioneer SX-828 receiver and the owners manual had the schematic in the back. My mother worked at a public television station and I got friendly with one of the technicians there. I showed him the Pioneer schematic and told him I wanted to build the power amp section. He said to me, "I have a better idea -- take a look at this," and he pulled a copy of Dan Meyers' 1969 "Radio Electronics" Universal Tiger article out of his file cabinet. A hundred twenty-five Watts per channel. My mind reeled.
I had built a few Heathkits up to that point, and had attempted some scratch projects from the ARRL Handbook and "Popular Electronics" with mixed success. The problem was, I could make PC boards and wire up a circuit, but I had no idea how the circuits worked. This bothered me a lot and I became obsessed with the idea of studying electrical engineering in college so I could learn how to design audio amplifiers.
So I got into Stanford and started taking the core EE curriculum sophomore year. I also read everything I could get my hands on about feedback and audio amplifier design. This was an extremely eye-opening experience for me because suddenly I had the design vocabulary, as it were, to understand and analyze circuits. I learned about circuits and also about signal processing and communication theory. And math, of course.
Naturally I also took art and literature and philosophy courses, which, on top of a pretty good high school education left me reasonably well-rounded, if not quite a Rhodes scholar.
My roommate for much of my college career was a mechanical engineer. There was a strong element of creative problem solving in his coursework and practical projects. He introduced me to motorcycling and I learned how to work on engines. After I graduated I owned a dozen bikes at various times, including several BMW flat twins that probably spent as much time in pieces as on the road.
I learned last year that my college friend was driving with his wife and kids in their RV up in a park in British Columbia when a tanker truck going the opposite way lost control and crossed into his lane. Robert and his family were incinerated. Easy come, easy go. I feel pretty bad about that. But I digress.
Another passion I developed early on was writing about technology. In high school I had a crush on a girl a year ahead of me. She went to Stanford (It's not a coincidence that I followed her there. We hardly spoke the entire time, though we're good friends now.) When I was a senior, I used to send her long, typewritten letters describing in great technical detail the projects I was working on. She tells me she enjoyed the letters and to this day is always asking me, "So, what are you writing?"
So, here's the thing. I place a very high value on learning and teaching. You may not know that I am the guy who coined the term "flywheel" to describe an important design feature of Jeff's supply. I was also, to the best of my knowledge, the first person to grasp the significance of the small input choke in the flywheel supply, to do extensive modeling of the circuit, and to explain in detail how it works. I have also built, tested, and measured a flywheel supply, confirming by direct observation the earlier predictions I had made.
I know from reading your comment above that you would prefer not to have to read through a page of explanation to learn something. Having read hundreds and hundreds of pages of textbooks, and having spent thousands of hours in classrooms and doing problem sets, I have to say that knowledge doesn't come cheap, but it's worth the cost. The problem is, it's a double-edged sword: the more you know, generally speaking, the more you realize how much you have left to learn. So, I'm not offended, but actually kind of amused to see you calling me closed-minded.
I've gone out of my way in my two longer posts this weekend to explain my response to Jeff carefully and in detail. I've also offered a whole bunch of useful, objective information that, if you were to make the effort to read and comprehend it, would actually teach you something.
In a sense, you have the best of both worlds here. You can hook up with guys like Jeff, copy their ideas and try them out for yourself. Or you can go to a forum like diyAudio where the population is much more tech-focused and, if you open your own mind and ask intelligent questions, you can potentially learn a hell of a lot more than Jeff could ever teach you.
It's really up to you.
I write for the pleasure of expressing myself. Jeff used to get under my skin, but in my old age I am learning to let go of things I can't control. As someone I highly respect said to me just the other day, on a completely different topic, "You know what you know, and other people know what they know. What you need to do is decide what's important to you. If it suits your purposes to associate with these people, then accept that you can't change them and focus on making the best of it. If you find it's not worth your while to stay with these people, then go somewhere else that better meets your needs."
I think you can see from our respective postings that Jeff and I have very different approaches to solving problems. I do think of myself as being a smidge broader thinker than Jeff, but heaven forbid I should appear to be bragging. I guess it's obvious from the sheer volume of writing I've done that I'm nothing but a self-possessed, arrogant sonofabitch. LOL!
Have a nice rest of your weekend.
Henry, I didn't have you in mind at all when I posted. I thought you presented yourself very well. When I disagree with someone I do not argue with them, I just tell them that I disagree and why and leave it at that. You seem to do the same.
There's a Greek word for stirring up the mind in a negative way, its 'tarasso' I believe. Its kind of a set-up manipulative trap and I see it all the time. Jeff is good at it. I used to do it at work quite a bit to see how quickly I could get people to fly off the handle. Most of the time it was too easy. I think a lot of what Jeff does/says is for his own entertainment. I like Jeff and I think he is a very helpful person, but he has a bit of a devious side like I do at times.
I do read through most of the posts and do learn a lot. Usually, the longer postings have detailed information on a subject when you read them all the way through. My complaint was that I would read a post, then know that the bantering back and forth was next, usually with little useable information.
I'd always wanted to be an EE since my early teens, but my lack of self-motivation and self-worth in my younger years cheated me out of the opportunity to go to college. Later I had gotten married and had a family, changed my thinking about myself, but could not afford schooling then. I'd rather be a good husband and dad than a divorced EE paying child support. So, it ends up that I'm at least having this hobby aspect of my interest in electronics opened up to me by way of the internet.
Anyway, like I said, I didn't have you in mind when I posted and its true that you can't change a person's beliefs easily (or sometimes at all). That's why I try to not argue with people. If they get you to argue, its like they already won.
I am not flaunting my personal credentials at all. It is Jeff who is belittling all EE's as a group.
Myself and others here have modeled exactly how Jeff's power supply works and why it produces the sonic signature it does. I never said it was bad, in fact I have outlined how I use a similar process with an outboard audio processor.
Rather than comment technically on this hypothesis he resorts to the name calling and belittlement. If he does disagree, then lets hear a professional technical rebuttle. Instead all we hear is "you didn't hear it".
I am policing nothing. I am simply offering an opposing opinion based on known principles and practice. It is Jeff who has a problem with that.
Though my last post may have seemed to be totally aimed at gusser and a couple others, part of it also applies to the admittedly overzealous Jeff too. As he said, he likes to stir the pot. I wouldn't let him manipulate you like that. Customers try to do that to me at work all the time. I don't allow myself to get involved in their personal issues or games.
My ears are super sensitive to any brightness/harshness in the upper midrange and high frequencies, but I love to hear the subtle details within a recording. I'd like to hear Jeff's PS in a well designed amplifier to see if its my cup of tea or not. I'm looking for something that is realistic, musical, and listenable for long periods of time. I plan on trying to build an amp with a low DCR PS soon. If it doesn't work for me and is not to my liking and if it can't be remedied to sound right, then that will be the end of it. I'm willing to give it a shot.
I'd like to see you two narrow down your differences by determining if Jeff's ideas work, hands on. Then, if they work, determine where they work, where they don't, what's good, & what's not so good. Like I said, maybe its just a matter of what you like to hear in music reproduction.
I'd like to see it handled on a 'professional' level as you both profess to be, then maybe Jeff's and/or your conclusions can be presented in an credible manner. I tend to believe things presented to me in a professional/logical manner, rather than following whoever shouts the loudest in an argument. I'm fairly new at all this electrical stuff and all I want is help in learning about how it works and how I can make it do what I want it to.
Jeff is not a professional when it comes to electronics. Where do you get that idea?
You just said you are new to electronics. So what qualifies you to make judgements as to others competence in the field?
It's not just the power supply stuff. And for the last time nobody ever said low DCR was not a good thing. The LSES is what is in question.
Forget the power supply. What about these ideas of needing 12ga wire in a 12AX7 plate circuit? How about this hacking up parts to replace wiring provided by a reputable manufacture? What of claiming different parts of music go through different resistors when paralleled? This are just some of the off the wall theories Jeff tries to cram down our throats.
When challenged with the lack of any credible published data to substantiate these claims, we get the EEs are closed minded rag.
Don't you think it's kind of silly for someone with no formal engineering background to make such claims against those who are professionals?
What in the world are you talking about??
You say this:
"What of claiming different parts of music go through different resistors when paralleled?"
Show us WHERE I said or claimed that. (Word search is your friend.) You totally misquoted me, that is not even remotely correct.
I do not want any such inaccurate statements posted from a "professional" like you.
Posted by drlowmu (M) on February 3, 2012 at 11:10:37
In Reply to: Best Damn cathode Cap posted by Neff on February 2, 2012 at 20:48:42:
Dennis Fraker explained this on this Forum, a few years ago, and has it PERFECTLY executed in his Serious Stereo 2A3 DC amps.
1) Never one cap, because the music will tune to that value.
2) Never a electrolytic.
3) Multiple value film caps rule !! Very often five or more in one Rk location.
4) Even though a cap can measure wide band, in cathode bypass duty, different value caps play the speaker in a NARROW band.
5) Put your main film cap value in place. Listen to that. Then, over time, you bypass that cap with lower value caps, determining the values, and the makes of film caps by ear. The process may take you up to a year of break in and listening time, to find the optimum values and types. If your system is mediocre, you may never find it.
6) If and when you optimize it, the results sound wonderful.
No free lunch, you have your work cut out for you, so, open up your wallet and pull out five C-Notes to start. You are in the audio big leagues now Neff, no more cheapo kiddie stuff.
One bypass cap value will do depth. Another cap value will do juiciness on the soprano's lips, and another cap value will do extreme air. Your job is to BY EAR, find the values and the best types.
And it is very audible on high efficiency speakers. Rk bypassing, almost everyone screws it up. Others have attempted it, and sorta half a**ed it, but ONLY Dennis Fraker, in 1989, had it down to a "tee". I hear it in all his amps when I listen at RMAF, assuming his digital source is clean, which is not always the case.
I'll stand 100% by that early post.
If you think about it, you may deduce why this is so Gusser. Listening to it is the way it is done, not with osillyscopes can one get it, nor with spectrum analyzers.
A film cap may measure flat, with simplified sinusoidal sources, but not play back flat under dynamic / music conditions. Different values, and different manufacturers caps, play back different parts of the audio spectrum, as heard at the speaker voice coil.
Nasty to contemplate isn't it !! That is OK, Dennis did the heavy lifting with this. ONLY Dennis did this correct in my experience. Kudos to him, that is just ONE reason why he gets my support.
this whole idea about multiple bypass capacitors and what they do has a very low transfer efficiency into my belief system.
It would be readily audible on high efficiency speakers, when doing all film bypassing.
From what I understand, it takes a minimum of five different values to get it REALLY optimized, which so far, only Dennis Fraker, in 1989 no less, knew how to do. Also amazing to me was his development of LSES or a modern power supply WAY back then, also found in the original 1989 Serious Stereo 2A3 amp.
Myself and a few other amateurs are working on learning this bypassing topic in 2012. It takes good LISTENING on a GOOD high efficiency audio system, and a big pocket-book to do right.
Read the article on the two stage DC SE stereo amp by the two Italian audiophiles in Sound Practices, about 1994 as I recall, re: Rk bypassing. They used three caps on each Rk, a film-only main cap, bypassed with a .22 PIO, bypassed with a .01 uF Silver Mica, three in parallel, LONG time ago. Its there, in print Lew.
I write this to you as "my" side of the topic. Do and think as you would like to, I have no big problem with you doing that.
I have no doubt that Dennis may have found a potion of 5 different capacitors that made HIM happy, listening to his chosen sources and driving his particular set of speakers using his amplifiers. In fact, I stand in awe of his patience and perseverance. But I think you over-state the significance. There is no general conclusion to be drawn from this story. It's just an interesting anecdote. It's not solid data, even in this touchy feely subjective audio universe.
Every time you add a capacitor, you have to take the bad with the good. You cannot say you are using capacitor X because it does a great job on female vocals and capacitor Y because it does a great job on male vocals, and, by gum, when you parallel them both, you get an amplifier that sounds fabulous on male and female vocals. That might happen, but it's a happy accident. It is equally likely that you will get an amplifier that sounds like shit on vocals.
Jeff, I like reading your posts.
I do have to ask, what happened to Dennis F in 1989? Did he get hit by lightening or run over by a farm implement? There seems to have been an epiphany in that year for Mr F. with all things solved at once. You have mentioned a few things that Dennis realized / discovered at that time.
As I understand it, here is my take :
Dennis told me he used to just modify amps, McIntosh 60s, MI-200s, and he had a pretty good reputation then with AudioMart people.
Some person gave Dennis $40,000 to develop a SE amp, and over two years, he came up with the Serious Stereo 2A3, his first-ever total amp design and build. He made four monoblocks, which I can see have hardly changed at all since then.
Film caps would go out of production, and wiring choices got better (Siltech), but Dennis thoughtfully engineered it from the start, optimized the design, so he has only made minor changes over the years.
The basis for the LSES supply came about as he and Dr. Charles Halijak, E.E. PhD. did amplifier mods. These two audiophiles used to get winders to copy the Citation 2 choke, and noticing that smaller chokes worked better, Dennis simply greatly refined the concept.
He is an unusual bird. Always honest. It is a fact he has spent several fortunes owning Hi Fi equipment. Never married, he has owned two good movie theatres, and a movie theatre service company. Besides being trained as a technician (electronics) in the Coast Guard, and working in mines, Dennis worked for Montana Power and many in-the-field / head electrical engineer positions, plus oil refineries with his Dad. Hey, that was Montana, go where the work is.
The power supply is just part of an amplifier, and the entire design and its lay out has to be conceptualized, optimized and built as one total piece. No bread boards. Just define the speaker load, design the amp, and build it in a chassis.
This is exactly what I am now doing in my 6AQ5 DC SE amp - whose photos I put up this week.
So, you don't like a crummy top end, nor do I.
What sort of speaker load do you need to power? What is its efficiency?
If its a high efficiency speaker, you are "golden" because I can email you good information on how to build a simple two stage DC SE amplifier.
You state this, which I strongly object to :
"Myself and others here have modeled exactly how Jeff's power supply works and why it produces the sonic signature it does."
(1) WHAT sonic signature are you talking about ?
(2) And WHO has modeled "exactly" how a modern supply works?? WHO, and using what tools ??
It is UNLIKE traditional power supplies, which HAVE a sound (they sound like a typical tube amp, never quite like the real musical events) because they deliver the "goodies" to the load out-of-time to the music, after it is needed.
The modern supply has VERY VERY little sonic signature, low storage time, and superb dynamic Z, about four times better, compared to the traditional supplies I have heard and PSUD simulated.
You will have NO answer to (1) and (2) above, because it is not true and is a figment of YOUR imagination. I respectfully object to such misinformation.
The properly executed modern supplies out there, enjoyed by their users, attest to the validity of my post.
How do you "time" a power supply to follow music? And let's be sure to acknowledge that music can be a piano solo to a full symphony, to heavy metal.
It works by having minimal storage time in the inductors, and in the caps, so that it can respond on time.
JLH did a great job demonstrating the problem with large Caps at the finals.
As for the L1/C1 portion, our friend Henry Pasternak provided theory and tests to verify that.
John Swenson did a fine job determining the speed of recovery needed, based on music signals.
If you email me your address, I will send you a PDF of Swenson and JLH, chronological, discussing this supply, and you can read that without all the bickering and noise. They are both EEs, like you are. My address is above. Have an open mind.
To me that implies it does not have sufficient capacity for the load. Sure there will always be some voltage variation with unregulated audio power amp supplies. But the design goal, at least the commercially practiced goal, is to keep this wandering to a minimum.
Consider this, if the power supply was a large battery bank, let's say in the case of a 2 watt SE amp, the battery bank is 100 amps. Now will there be a recovery period here?
Now I have no doubt this hypothetical battery supplies amp will sound quite different than a LSES amp. It will be "lifeless" and "dull" to use your words - right? See I do know what is going on here. The LSES is a dynamics enhancer. And that does sound good. But is it real?
Tell us about the processing equipment in your rack at home?
Do you use this equipment at all times?
I have DBX 3BX3 and a 3BX1. These are the later models but there is also the coveted DBX4. I have a relay bypass unit that switches them in and out of the path as needed. The internal bypass switch is fine but I have the relay bypass under remote control from my Ipad along with a host of other system functions.
Keep in mind this is a home theater setup. Older movies and shows benefit greatly from a little dynamic range boost. Modern Bluray disks need no processing.
In my music system I don't even have a preamp. CD player with built in motorized analog volume control direct to the power amp.
DBX made many models of these "companders" in the 1970s. You can always find the earlier units on EBAY. The later units like mine are not as commen but they do come up now and then. The basic upgrades over the years were better and better VCAs which is the heart of the unit.
Batteries on B+ supplies for tube amps, I've been told by people I respect, is NOT the ultimate in sonics.
No Gusser, you really do not understand, but you think you do, and that is the problem.
PLEASE do me and you a favor, (this is the second time I bring this up).
Let me send you a email attachment from EEs John Swenson and John Hasquin, so that you may read it in chronological order. You have bits and pieces, but I can tell - truly not a full grasp.
The modern supply is not an enhancer at all, it delivers the goodies when it is needed, and not after the note has come and gone.
Have an OPEN mind, like a good professional engineer should, and send me your email address, mine is above. It will enhance the common ground we share between us, so ACT now, today !!
You try marginalize me by saying I mock EEs and am I not a engineering professional, so what I say can't matter.
I ask you to keep an open mind. If what I say doesn't matter to you, how about graduate Electronic Engineers??
We have THREE EE professionals who have written about "modern" supplies on this Forum, three who have ACTUALLY built it, and tested it successfully. All three claim it provides SUPERIOR REGULATION Gusser. Two actually listen to them.
Are these three guys, listed below, professional enough for your tastes ???
Two other questions come to MY mind about you :
(1) WHY are you unwilling to read my twice offered compilation of your fellow electronic engineer's work / posting on this subject????
(2) WHAT does that "look like" as far as your own "professionalism" and your open-mindedness to look into a new subject.
Surely, these three following Forum posters, can be considered as "professionals", although NONE touts themselves as being so, like you do :
1) Henry Pasternak (Opus48, No 1.)
2) John Swenson
3) John L Hasquin (JLH)
Good job, good man !!
I do admit, I stir the pot and tease the "straighter" (non imaginative) EEs way tooooo much...its sorta fun. But - it gets me in trouble.
Yes, A-B sessions might help make progress quickly. The guy who is now posting as "rage" just did one last week, with a partially finished amp, and Willie did a "show and tell" with his reference 2A3 DC amp in St. Louis a couple weeks ago. Willie Rivers Jr. (Drummerwill) is COOL, nice person.
Its not just low DCR, but the use of lower HY and lower C that comes into the mix. Respected Engineers and Forum members such as John Swenson and JLH (John L. Hasquin) have used this technique very productively in their amp designs, as has and is Larry Moore of UltraFi. I don't really know who Deathtube is, but he is certainly independent and having a ball with listening, on modest equipment too, which is refreshing.
My current build, a SE DC6AQ5 amp, WAS to have been modest, but I can see I am getting carried away
If you need any application help, or have questions, feel free to contact me.
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