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Hello!
Hello, IŽm planning on buying the Hammond 193Q choke with a rating of 10H/500mA and use it for choke input duties on my amplifier, and my question in that regard is how much more inductance I can expect from the choke when used with "only" 100mA? I guess it will be somewhat larger but how much? Are we talking about a 10% increase or perhaps 20%? I have send an e-mail to Hammond but havenŽt heard anything from them yet.
Regards, Vidar
Follow Ups:
hey,
Unless specifically designed to do so (swinging choke), inductors remain reasonably linear with DC current from 0 to the rated DC current.
By reducing the DC current and increasing the AC current you typically get more inductance due to cores having higher permeability at higher flux levels but with this higher flux the chances of mechanical noise also increases.
It is also important to understand that mechanical noises are a function of build parameters and tell you that you are operating at an AC (or AC+DC) level that the build cannot keep stable.
dave
L1 meets critical inductance for your circuit?L1 is 10H and 53 ohms?
L1 is 14.6 LBS weight?
The choke is enclosed and not open bracket?
Where is the good Drlowmu?
dt 667
Edits: 03/03/12
Please remove it and go here:
Nice try, Wheezer.
How about a Fraker-Medwin/modern power supply forum?
dt667
Mr.Wheezer,With all due respect...
Do you really think that I would allow myself to be marginalized in such a manner?
There is no activity on that Yahoo forum.
I post in the DIY Tube forum until another more appropriate forum is created here on AA.
That is final.
dt 667
Edits: 03/05/12
the kingdom can be yours just ask Rod how you can get the key.
dave
Drlowmu, head of council, awaits his return from the Temple Mount for further commandments.
It was formed by one of our cool and experienced UK DIYers, and it never went further, and it is a dead end.
This is an open Forum, and YOU are not able to dictate policy, only the moderators have such power.
If you don't like my posts, 'skip em. Saves bandwidth up here that is silly.
Hope "we" didn't mess-up your sand box.
Jeff Medwin
OK, but why do you have to highjack another person's thread?Start your own thread.
The original poster was asking questions about "true" choke input filters. Filters that use input chokes that do meet critical inductance.
This thread was not about non-critical inductance chokes.
Stop highjacking threads.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 03/05/12
Tre,With all due respect...
The topic was about a guy that wanted to use a 10H input choke in his PS.
I posted something that could be an alternative for him to consider.
I would suspect that he can determine if what I posted was worth considering or not.
No harm , no foul.
Look at my two recent posts on the flywheel and transfer efficiency of wires.
There were a lot of negative comments and comments not related to the subject matter.
Did I complain or care what you guys posted on my threads?
Did I accuse others of hijacking my threads?
Did I try to censor the opinions of others?
No.
In the future, if anyone objects to one of my posts, feel free to report it to the moderators of this forum.
Allow them to do their job and resolve the issue.
But take note, I will not be marginalized here by anyone.
I am fair with others and expect that in return.
dt667
Edits: 03/05/12
"The topic was about a guy that wanted to use a 10H input choke in his PS.I posted something that could be an alternative for him to consider. "
No, you did not. You posted this,
"L1 meets critical inductance for your circuit?
L1 is 10H and 53 ohms?
L1 is 14.6 LBS weight?
The choke is enclosed and not open bracket?
.................."
Now if you had just said something like,
"Hey, sorry to butt in but you might want to try..................."
that would be one thing but that's not what you did.
Your questions have the air of belittlement as if you are trying to put the original poster down.
Keep doing that and you will marginalize yourself.
marginalize, marginalise [ˈmɑːdʒɪnəˌlaɪz]
vb
(tr) to relegate to the fringes, out of the mainstream; make seem unimportantTre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 03/05/12
Tre,
With all due respect , we have a moderator in the DIY Tube forum.
If anyone has a problem with any of my posts, report it to the moderators.
Let the REAL moderators of the DIY Tube forum determine if the content of my posts need to be removed or not.
I will live with their determination and not complain about it or get upset.
As far as I can tell, vbenonisen did not even bother responding to my posts or Drlowmu's post.
He simply ignored them. Good for him.
That is all you guys have to do if you don't like what you read here.
Ignore the post and move on.
Your lives will be much easier.
Can we get back to our tube circuits now?
dt 667
The moderator typically steps in if certain lines are crossed.
Foul language, viscous attacks, personal marketing etc.
On occasion "a shit stirrer" has been sent on a vacation!
Pick the battles you can win or negotiate
Good luck!
That is a low inductive energy storage thing...plenty of capacitance on hand in 40-50 uF lumps.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
agreed douglas!
LSES would be around 150uf per channel .... ~ 300uf for the entire amplifier if a stereo amp.
"Modern" would be less, around 110uf per channel...roughly 220uf for the entire amplifier. which is what is in my amplifier.
Moderate amounts of C in both supplies.... its really the "distributed in 50uf chunks" that sets it apart....as well as the very small chokes... I like both concepts but realize I don't have an advanced technical understanding.
150uf per channel is a lot of storage for say a 50w PP amp. It's a HUGE amount for a 2w SE amp. Look at the classic HiFi designs of the 1950s and 60s. You had sometimes only 20-30uf and a 2hy choke before the finals. And those amps performed quite well. The Citation 2 was the first amp to really pile on capacitance with around 200uf and it was a late comer in the tube glory days.We use large caps today simply because we can. A 500uf 450v capacitor was simply not available in those days. Today it's a common commodity part thanks to switch mode power supplies.
Remember folks it comes down to watt-seconds or joules of energy storage. A 200w SS amp needs around 40,000uf at 75 volts per rail. A transmitter tube based 200w amp at 1200 volts B+ needs far, far, less capacitance to achieve the same ripple factor.
Edits: 03/06/12
that 150uf value does include the final RC stage feeding the driver, for what its worth.
I don't think Dennis uses 50uf caps (smaller I think) or that much C in his supply, but what I have seen of LSES is two LC stages, .3-.5 henry chokes and 40-50uf caps per stage.
" You had sometimes only 20-30uf and a 2hy choke before the finals. And those amps performed quite well. "
so it was ok in those amps, however presented today in a "gorilla marketing" fashion it no longer works?
I think you guys just like to argue.
Because "building amps" has become a hobby for me, and I realize I'm a "newbie"... I'll build the damn thing and listen.
I'll also build other types. Choke input (l critical), etc... not because I don't believe the doctor -because I want to learn.
as I build more I'd like to get a good understanding for how measure these things.
To me this is far more productive than arguing.
The adamant arguing against these concepts, "LSES and Modern supplies" , pretty much everything drlowmu pushes... is half of what inspired me to build the thing.
The 2a3 DC amp, with Jeff's guidance on the build .......sounds excellent to me.
However non scientific these conclusions were arrived at - they do work....at least from what I hear. Maybe measurements tell a different story. I doubt it.
Then why not listen to the people here with professional electronics backgrounds and education. Otherwise you are just hacking around. And that's fine if this is just a hobby. Some of us here however do electronic design for a living.
Like I said below, if Jeff would simply outline his circuits and tell us he likes the way that sound that would be great. But instead he has a long history here of belittling others designs and spewing out technical mumbo jumbo that is impossible under the laws of physics. I and others have explained several times what is going on with Jeff's "fast power supply" We have explained why it works on an SE amp but does not on a PP amp. We have acknowledged and accepted his description of how it sounds. I for one just don't want my power amp to play the role of a signal processor. Instead of having a technical discussion Jeff just tells us we are clueless and wrong. Yet he has no plausible technical offering himself.
This is why he gets jumped on here so much.
I did think the yahoo group was pretty funny.
Well, a bit of energy storage is dicatated by filter type and the rest of the PS...not to mention how the load's PSRR works with it. If you've got PSRR to burn, one can get away with less filtering.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Douglas,
I was busting...:-)
Actually, a 500mA load would require about a 0.6H choke.(cap input)
Cheers,
W
Edits: 03/05/12
I haven't gotten to 500 mA on a single amp yet. got close to 300 mA with the 600V 813's though...:) Funny...I got no workable solutions from anybody on how to 'improve' that PS.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Hey Douglas,
I've got 330mA on HV A/B triode strapped 6550 stereo amp. C-input. The choke calculates out to about 4H (B+, 500V) including the FE tubes. The proper sized L combines FE plus the % of B. Then another choke for the FE, around 60H, IIRC.
Adding an additional CL section helps kill the ripple and minimize the total capacitance, especially at C1, then C3 IMHE of course.
Just finished a 600mA DAC (LV obviously). The proper sized chokes are 600mH.
The above were built by Jack a while ago.
Choke input is a different beast altogether but we know that...
Cheers.
Deathtube,
Don't ask "me" about 10 HY 500mA. chokes.
That was the first choke size I ever A-Bed in 1982, when designing the supply my very first DIY 2A3 amp. 10 HY. had fabulous low end, but it RUINED the timing of ALL musical events through it !!
Hands down "F-" grade..... for 10 HY (at about 40 Ohms) in 1982 A-B testing. How enlightening that listening session was to me!!
Used a 5 HY 500 mA choke instead, and by 1985, I discovered the ESPEY 3 HY 24 Ohm choke, which I even got Herbie Reichert to use in his Flesh and Blood amps.
Deathtube, since 1985, I have not used over 3 HY / 24 Ohms in any of my audio amps.
In 2012 it is L1 @ 35 mHY - under 1 Ohm and L2 @ 2.2 HY (maximum) - under 7 Ohms.
Don't ask me again about 10 HY Ls in power amps my friend. YUCKIE !!
Jeff Medwin
Drlowmu,The 10H Hammond choke is $85 at AES.
He could get (2) Triad C-56U's L1's and (4) Triad C-40X L2,L3 filter chokes for that money.
Enough for (2) LCLCLC flywheel filters to the finals.
Add another RC for the driver tube plate supply. Simple enough.
From my own listening experience, a very effective filter.
Of course, a PT with a low DCR secondary winding is not always so easy to find.
dt667
Edits: 03/04/12
.
Unless you post a schematic or a link to more info what you posted is effectively worthless.
Put yourself in the position of the neophyte, your fragments of info are impossible to put together.
.
Hi,
You are new up here. I have posted thousands of times in the last eight years on this subject. My message is consistent. To save you trouble and time, email me your address, and I can send chronological attachments of what this is all about. You will find it thought provoking, and it should easily lead to higher performance audio amplifiers for you.
Jeff Medwin
nt
.
Have Fun and Enjoy the Music
"Still Working the Problem"
I did as Jeff asked and contacted him. He sent me information for me to read.
If I started another thread, you, wheezer and others would jump in and tell us how stupid we were. I've read on other forums discussing low dcr power supplies by very knowledgeable people (without all the hostility that happens here)who believe there is merit to the idea...but with issues to be worked out. Isn't that what DIY is all about?
In the end, it's about enjoying the music!
Listening to my 300b's
Have a good day!
"If I started another thread, you, wheezer and others would jump in and tell us how stupid we were."
No, I don't believe that would happen. The trouble in the past has started when a thread is hijacked to turn it into a discussion of something different to what it was intended to be, particularly "LSES" or, to give it its re-baptized name, "Modern PS".
Nobody with any technical background on this forum ever said low DCR is not a good attribute. Although sometimes way too much emphasis is placed on it.But these "tuned" power supplies have some serious engineering issues. Those who choose to spend their money building should hear both points of view - don't you think?
Edits: 03/05/12 03/05/12
"But these "tuned" power supplies have some serious engineering issues. Those who choose to spend their money building should hear both points of view - don't you think?"
I don't agree on the "serious engineering issues" , however I do agree that both points of view should be considered.... maybe even built!
In all the LSES talk it seems one is attempting to tune the power supply to "follow music". Now how do we do that when music can be anywhere from a piano solo, full symphony, to heavy metal. And since an SE amp has a fairly constant current draw, what exactly are we following? Ahh, but that's why it seems to work on SE and not on PP.This idea that audio is "fast" is silly. Your home WiFi is in the ghz range. That's "fast" by electrical engineering standards.
I and others have explained why this power supply makes a "fast" sounding amplifier. It's adding the function of a dynamic range expander to the amplifier. It may sound exciting but it's no longer a true amplifier, it's more of a signal processor.
If you like that, fine. I use dynamic range expanders my self for older material however they are an outboard unit that can be switched out.
Edits: 03/06/12
----And since an SE amp has a fairly constant current draw...
On what sort of time scale? Instanteneously it varies all over the place. A Class A PP amp will have a much more constant loading of its PS in comparison.
As to the rest, the music signal will be effectively random, and the PS should not respond to it. Your singal processor idea is likely pretty close.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
You really don't have a clue Gusser!!!
And furthermore, you never HEARD this, have you ??
You are only theorizing and only just GUESSING.
The proof of the pudding is in the hearing.
Jeff Medwin
I have plenty of clues. These are tools an experienced EE has. The ability to look at a circuit on paper and analyze how it behaves in real life. Of course that's still no substitute for the ultimate test of building a prototype and testing, but analysis tools based on real life experience is what education and experience is all about. When Boeing designs a plane today do you think there is any doubt it will fly?You seem to like PSUD now although I saw a post from you around 2006 discounting it. Well PSUD is a primitive sim tool by today's standards. It's a great tool but hardly sophisticated. My point is much of today's electronic is never even bread boarded anymore. It goes from sim to PC board. The point is these sim tools are based on years and years of knowledge and experience. We now know how a circuit will perform in great detail even before it's built.
You response to this dilemma is to use your own words, "consistant". You have no technical rebuttle because it is you who doesn't understand how it works or what is really going on electrically. You like how it sounds and that's fine. Why not just keep it at that and let those with the knowledge, education, and experience determine why. Note that I never said it sounded "bad". I did say it is not an accurate representation of the input signal minus the gain. That is a fact and quite easy to prove on a test bench.
Telling experienced EEs and technicians they are clueless in circuit analysis with your technical background as a measuring stick is just labeling yourself a fool.
Edits: 03/06/12 03/06/12 03/06/12 03/06/12 03/06/12
hey-Hey!!!,
Random searching has value. I'll give as examples disccovery of the cocoa bean. I am sure lots of folks died in this experimentation; oooops, that isn't good to eat in quantity...this stuff OTOH has promise. Lots of pharmaceuticals arrived this way, curare, opium, tobacco...and so on. This sort of research process does have limitations, and they're pretty well understood( not to mention plentiful ).
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Obviously I don't know the difference, but what I read being discussed was what Jeff is doing. If I had become a EE like I once thought, I'm sure I could discuss it more intelligently.
Yes, all sides should be discussed, but if all things followed "the book", where would innovation come from? I'm like Jeff in my profession, "outside the box"...so I guess I'm sympathetic.
I had a golden that looked exactly like Gus...brought back good memories. Goldens are the best pets ever!!!
"Goldens are the best pets ever!!!"
Golden what? Hamsters? Eagles? Sections?
Pet Goldens of all kinds....Golden Rivers, Golden Beauties, Golden Linings, Golden Ears, and Golden Nuggets.....hehe
golden years....yes I need some...these are my pets...
these golden moments, golden skies, and golden goddesses....mmmmmmmmmmmm....yes now we are talking....
hehe Golden Music, and Golden Good stuff to you,
-3db
How about Tweaks?
BTW, Nobody made reference to "stupid".
Edits: 03/05/12
Its not a tweak, except to those who don't understand it, like you.
Its truly good AUDIO engineering that produces a here-to-fore unobtainable high performance result, immediately heard and appreciated by LISTENERS.
Thats all it is.
Its not for conventional theorists who never LISTEN to it. But post as you like guys, even if you have ZERO practical experience with it.
Jeff Medwin
hey-Hey!!!,
At 100 mA of DC you'll be well into the largely constant inductance zone. You don't say how many volts you'll be applying to it though; with input service the AC component will not be small. I can give you a point at which that particular choke served well. 400-0-400 applied full wave with a DC component of ~170 mA. It stood this w/o complaint like buzzing or saturation. The output DC matched PSUDii well, indicating it was still behaving like a 10 Hy choke.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Thanks! Good to know. Was a bit worried about mechanical noises, but IŽll guess the monstersized choke can handle it.
I have just one more question regarding LC-supplys:
When used as a power supply for the output stage of a single ended amplifier the current in the output transformer swings up and down with the music around the bias point, and the minimum current is a little difficult to pinpoint precisely. Do I just draw the loadline of the output tube and use that as a reference?
Vidar
Vidar,
A SE topology will run class A. You won't see enough current swing to be concerned with your choke inductance range.Draw your load line on the published plate curves. Keep in mind that a Choke input will drop your B+ around 10% down stream.
Stuben
Hi!
Those current swings due to the music signal will be mostly supplied by the last filter cap in your supply, so your input choke will not see them, at least only to a much lesser degree.
I'd recommend a bleeder resistor which ideally ensures critical current draw at all conditions even if the output tube fails and does not draw current. Depending on the voltage this might require to dissipate an unpleasantly high power in the bleeder. In that case make sure your caps have a voltage rating which is able to cover such falut conditions in which the voltage rises by up to 50%.
I'd rather get a choke which is speced for the applicatoin than getting one with much higher current and hoping it will not procude noise
Best regards
Thomas
Hello!
Thank you for your answer. Good to know that the input choke doesnŽt need to "swing" as much as I first thought.
If I follow your recommendations my 300B monoblocks probably need bleeders with a current draw of around 40-50 mA and that will indeed produce a lot of heat. I probably make separate power supplies for the input and driver stage to get better flexibility when experimenting, AND to reduce the risk of destroying everything if something goes wrong.
Regards, Vidar
Vidar,The critical current, in mA., roughly = V/L. When a 10 H. 1st inductor is used, a 10 KOhm bleeder is correct. You take it from there.
Eli D.
Edits: 03/03/12
The more important parameter you should ascertain is what is the capacity of this choke in terms of AC ripple volts if your going to use it as a choke input.
MSL
Builder of MagneQuest & Peerless transformers since 1989
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