Hallo Carlos,
you should not think so. Just because there is already much has been destroyed semiconductor parts and sacrificed a lot of time for debugging and troubleshooting, you should definitely find out the cause of all observed effects.
It is often not a single reason, but the interplay of many things (like core saturation, unexpected and unwanted transition resistance in the transformer winding, external wiring or connectors, sporadic faulty rectifier and many others).
For me, the destroy of so many parts through certainly failures by your transformer is very curious.
If you have the transformer identified themselves clearly as error-causing component, you should never throw away these faulty device so that others can check through certain measurements to the characteristics, which provide such destroyed transients.
By the way - what about your sine wave from the mains connections?
If where are residual dc components or clipping effects you will hear hum or buzzing effects by the most of toroidal transformers.
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it's possible the core of the transformer is cracked if it's got a ferrite core. that would make it's behavior under load unpredictable and erratic. with all the shrink wrap and wire on it it's impossible to tell by visual inspection. either that or there's a bad internal connection in one of the windings that begins arcing when you draw any serious current (or a defective thermal fuse). the way to test it to see how it behaves under load with no rectifier, caps, etc... would be to connect the secondary directly to dummy loads (8 or 16 ohm) and look at the AC waveform with an oscope. other tests would be to measure the capacitances between windings (and don't forget any low voltage windings as well). i'm just as curious as you are to know why. i wasn't really getting on your case about the filter caps. but was trying to go through a process of elimination of any possible causes of the problem. btw the threads on those caps are most likely american 10-32 threads (#10 screw, 32 threads per inch)
Ferrite core for 50(60)Hz mains transformer???????
But at photos it looks like this transformer has core with circular cross-section, and it is very strange for mains toroid...
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I am very happy i give up...i quit about that transformer.
a lot of hard work....many parts lost..... now i am listening my Dx Blame ST...a very pleasant one...lovely sound.
regards,
Carlos
a lot of hard work....many parts lost..... now i am listening my Dx Blame ST...a very pleasant one...lovely sound.
regards,
Carlos
But the problem is in your amplifier, not in the transformer.
Different amplifier circuits designed and built by other people won't fail with this transformer.
A good electronics designer never runs away from problems without fully understanding them and gaining control over the situation.
Me and many people here could build a good amplifier with the "faulty" toroid without any problem.
I get most of my electronics knowledge by facing strange problems like yours until the exact electronic process behind is well understood.
Different amplifier circuits designed and built by other people won't fail with this transformer.
A good electronics designer never runs away from problems without fully understanding them and gaining control over the situation.
Me and many people here could build a good amplifier with the "faulty" toroid without any problem.
I get most of my electronics knowledge by facing strange problems like yours until the exact electronic process behind is well understood.
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I am glad you are highly intelligent and can understand that Wahab
Others cannot.. or they are blind for obvious things....or the need to be boring is bigger than the intelligence....or other reason move them...not nice reasons i suppose.
As you know Wahab, when you quote his words, you force me to read the text..when i have decided not to read them anymore....you could be cooperative and read yourself as you appreciate him.
Inform this gentle person, using a kind name, Eva, that i have already married three times...not more interested in a fourth try..also that i am too much old for her...so...i am sorry not to enter this charming game.... also the one could stop the harassment, the stalking, as i am not interested in her conclusions.... anymore... since i perceived bad intentions.
400 guys ( a little bit more than that... and reported, all them in this same forum..documented with pictures) the ones have built my amplifiers, can say if i am good designer or not...the ones have not listened...sadly have not idea what they're talking about, also their thougths are not considered valuable to me..without listen..no conditions to evaluate things..simulators and calculator machines have not ears.
If one day, i met scope and spectrum analiser, distortion meter and other instruments, walking going to shop electronics..then i will respect theories..for a while, i respect human ears...as humans buy audio equipments.
Send my good bye for the kind lady..wishing her the best she deserves.
regards,
Carlos
Others cannot.. or they are blind for obvious things....or the need to be boring is bigger than the intelligence....or other reason move them...not nice reasons i suppose.
As you know Wahab, when you quote his words, you force me to read the text..when i have decided not to read them anymore....you could be cooperative and read yourself as you appreciate him.
Inform this gentle person, using a kind name, Eva, that i have already married three times...not more interested in a fourth try..also that i am too much old for her...so...i am sorry not to enter this charming game.... also the one could stop the harassment, the stalking, as i am not interested in her conclusions.... anymore... since i perceived bad intentions.
400 guys ( a little bit more than that... and reported, all them in this same forum..documented with pictures) the ones have built my amplifiers, can say if i am good designer or not...the ones have not listened...sadly have not idea what they're talking about, also their thougths are not considered valuable to me..without listen..no conditions to evaluate things..simulators and calculator machines have not ears.
If one day, i met scope and spectrum analiser, distortion meter and other instruments, walking going to shop electronics..then i will respect theories..for a while, i respect human ears...as humans buy audio equipments.
Send my good bye for the kind lady..wishing her the best she deserves.
regards,
Carlos
Attachments
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Bob Dylan said:
Engineering is not about avoiding problems (that's for politicians) - its about solving problems and therefore facing them.
Why do you think, having a profound understanding of what is going on, will prevent you from also using your ears to make things sound good?
The contrary is the case. Only with a profound and deep understanding of what is really going on, you will be able to use your ears as an instrument, that can tell you what you can do to make your design sound better.
So while you accuse those as evil minded with bad intentions who are pointing out to you that there is more to audioengineering than just ears, you slam the door in your own path, forcing you to end up running in circles.
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Joined 2009
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weird things from Toroids....
"Potential Difference Inc Bi-Toroid Transformer Demo"
YouTube - Potential Difference Inc Bi-Toroid Transformer Demo
"Potential Difference Inc Bi-Toroid Transformer Demo"
YouTube - Potential Difference Inc Bi-Toroid Transformer Demo
Priorities only..... i really love amplifiers....today i am building one more
I do not want to spend too much time researching other things than amplifiers, i am already very old to waste time with things are not my personnal priority....if transformer is bothering..then better to junk it and try another one.
I can live my life without some answers..there are a lot of things we have not answers...why we are here...where is God...does God exists really....what is the purpose of life...so...i can stand for one more doubt..the transformer.
The ones that loves..go searching and researching..and if they want to be kind and inform solution...i will be gratefull..will kill my curiosity..not a need...just a curiosity.
A friend from Holland send me a suggestion.. i will give a try...to insert resistances in series with primary and also from the rectifiers to the filters...i will do that...just to try something.....curiosity again....in my mind this will just kill the supply power, with the introduction of series resistances...but.... maybe something happens and will answer my questions.....will do that AFTER finish my new amplifier....a 360 watts unit.
regards,
Carlos
regards,
Carlos
I do not want to spend too much time researching other things than amplifiers, i am already very old to waste time with things are not my personnal priority....if transformer is bothering..then better to junk it and try another one.
I can live my life without some answers..there are a lot of things we have not answers...why we are here...where is God...does God exists really....what is the purpose of life...so...i can stand for one more doubt..the transformer.
The ones that loves..go searching and researching..and if they want to be kind and inform solution...i will be gratefull..will kill my curiosity..not a need...just a curiosity.
A friend from Holland send me a suggestion.. i will give a try...to insert resistances in series with primary and also from the rectifiers to the filters...i will do that...just to try something.....curiosity again....in my mind this will just kill the supply power, with the introduction of series resistances...but.... maybe something happens and will answer my questions.....will do that AFTER finish my new amplifier....a 360 watts unit.
regards,
Carlos
regards,
Carlos
Attachments
Hi Destroyer;
I had a closer look to the curve with the old transformer in.
The rising edge looks perfectly ok, while the falling edge is thinner, indicating a faster transient. It seems to have a slight ripple too.
I`d examine the voltage gain stage, especially the miller caps.
Possibly that amp is slightly undercompensated.
Regards
Arne
I had a closer look to the curve with the old transformer in.
The rising edge looks perfectly ok, while the falling edge is thinner, indicating a faster transient. It seems to have a slight ripple too.
I`d examine the voltage gain stage, especially the miller caps.
Possibly that amp is slightly undercompensated.
Regards
Arne
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Thank you Yeti..... this schematic, the compensation, use a different idea
When using from base to colector, usually 27pf, 33pf or 39pf is perfect...when doing this way..from the second VAS to the first one, we use bigger values, and this method does not destroy the signal the same way the traditional method does.
When we enter with a sinusoidal signal and then we go increasing frequency, with the previous, standard and normal method, the Miller capacitor installed using the more traditional values, then above 60 kilohertz you start to have the former sinusoidal waveform beeing transformed in triangular waveform.
With 100pf, seems it is undercompensated...or... at least this is the effect we have..i can increase frequency till 200 Megahertz and the waveform continues to be perfectly sinusoidal.... so... that transformation in triangle does not happens same way....... this can happens if we reduce the capacitor value in the traditional way (from colector to base).
Installing there 3 pf, or 5pf, or even 8pf.... so..undercompensating..also we have not the waveform transformed in triangle when you enter sinusoidal and go increasing frequency.
So...seems to me not a real undercompensation, but a relative undercompensation, or a undercompensation result ... some kind or or undercompensation resultant...the same undercompensation effect..... say...clean and not distorted (transformed in triangle when you enter sinusoidal) waveform.
thanks,
regards,
Carlos
When using from base to colector, usually 27pf, 33pf or 39pf is perfect...when doing this way..from the second VAS to the first one, we use bigger values, and this method does not destroy the signal the same way the traditional method does.
When we enter with a sinusoidal signal and then we go increasing frequency, with the previous, standard and normal method, the Miller capacitor installed using the more traditional values, then above 60 kilohertz you start to have the former sinusoidal waveform beeing transformed in triangular waveform.
With 100pf, seems it is undercompensated...or... at least this is the effect we have..i can increase frequency till 200 Megahertz and the waveform continues to be perfectly sinusoidal.... so... that transformation in triangle does not happens same way....... this can happens if we reduce the capacitor value in the traditional way (from colector to base).
Installing there 3 pf, or 5pf, or even 8pf.... so..undercompensating..also we have not the waveform transformed in triangle when you enter sinusoidal and go increasing frequency.
So...seems to me not a real undercompensation, but a relative undercompensation, or a undercompensation result ... some kind or or undercompensation resultant...the same undercompensation effect..... say...clean and not distorted (transformed in triangle when you enter sinusoidal) waveform.
thanks,
regards,
Carlos
Probably *meant* kilohertz. But if it were 200 MHz, it would probably *look* like a sine wave on the scope, even if it were highly distorted. Bandwidth limitations - everything looks like a sinewave.
the slew rate is defined by the maximum current the LTP inputstage can pass to the VAS and the value of the miller cap (under the premise the VAS is designed properly).
We get SR = I/C_miller.
For the slew rate it makes no difference if the VAS consists of one ore two transistors, as long as both versions are designed properly.
If you get a higher undistorted frequency with the higher miller C, then you have either had a lower outputvoltage, or a higher maximum input current, or both. (or something else, but only if the premise of a properly designed VAS was violated)
So, what where the conditions, Carlos?
Without naming them, your statement is worthless, because it describes an unexpected result, that asks for an explanation.
We get SR = I/C_miller.
For the slew rate it makes no difference if the VAS consists of one ore two transistors, as long as both versions are designed properly.
If you get a higher undistorted frequency with the higher miller C, then you have either had a lower outputvoltage, or a higher maximum input current, or both. (or something else, but only if the premise of a properly designed VAS was violated)
So, what where the conditions, Carlos?
Without naming them, your statement is worthless, because it describes an unexpected result, that asks for an explanation.
Carlos is saying this problem shows on different several dissimilar designs when powered with this toroid, not just one particular configuration.
If this is the case, then this is what makes it such an interesting issue... but the clue will be in observing closely the DC rails, and in all the grounding.
The evidence will be there... it's just finding it.
It may only take a volt or two of "ripple" on the rails mirroring the output signal to cause gross instability... and I proved this to myself years ago unintentionally by inductively coupling the plus and minus DC rails in my own Lateral FET amp during design and development.
Quite how a toroid could accomplish that when it feeds a substantial reservoir/smoothing arrangement I don't know... but it seems "something" is happening from the evidence of several designs being similarly affected.
Perhaps even 'scoping the AC from the secondaries may reveal something when the amp is loaded.
200 kilohertz is the correct frequency, of course, a mistake
My poor scope does not show me 200 Megahertz.
I will try to scope the transformer...i have something to try on it....but will do it without dead line.
But first, i will find some time to finish another amplifier...then will be watching the transformer once again.
It is very powerfull this transformer......nice one electrically...also works cool (cold)...different than others can stay all day long without overheat the metal core....sadly produce strange signals.... i will also try it together this new ampllifier (other kind of board..different board)... then i will produce more pictures.
The picture i have posted does not show the "ghost" i have watched..something very strange that reminded me the good old days i worked in television station... looked alike one line of video (1H)..showing sync pulse, chroma pulses, video and black level.
I am just an advanced amateurs....skilled to listen things, to build amplifiers and to force them to operated....i am good to compare amplifiers..but i am not an engineer Krachkiste, there are several things i do not understand...i cannot answer you.... all i can say is what i have measured..the value was decided by Douglas Self...you can see the same value in his Blameless...this amplifier started copying the blameless and then tweaking it.... it is not too much different...since the very beginning i had troubles......i think was the transformer... i could not use the CCS to the VAS.... was a hell on earth..fuses burning...transistor overheating...oscilation i think...i had not time enougth to scope the thing before it has burned.
I cannot make statements based, or explained in theories...i do not know most of them..also, for a destiny accident, i do not like them..... if i do not like them because i do not know theories is possible...also that i do not like then because they have not helped me too much.... all results i can post are observation of what's happened.
Sorry, you may want me to produce some tests..... i understand you may not be too much happy with me....i may do some tests, not all them, i have already explained, i have another priority than to inspect this transformer..there are a lot of things i want to make in advance..will be doing, some tests, slowly.
Dear Mooly, you are always friendly...will eat more chicken...less cow beef.
regards,
Carlos
My poor scope does not show me 200 Megahertz.
I will try to scope the transformer...i have something to try on it....but will do it without dead line.
But first, i will find some time to finish another amplifier...then will be watching the transformer once again.
It is very powerfull this transformer......nice one electrically...also works cool (cold)...different than others can stay all day long without overheat the metal core....sadly produce strange signals.... i will also try it together this new ampllifier (other kind of board..different board)... then i will produce more pictures.
The picture i have posted does not show the "ghost" i have watched..something very strange that reminded me the good old days i worked in television station... looked alike one line of video (1H)..showing sync pulse, chroma pulses, video and black level.
I am just an advanced amateurs....skilled to listen things, to build amplifiers and to force them to operated....i am good to compare amplifiers..but i am not an engineer Krachkiste, there are several things i do not understand...i cannot answer you.... all i can say is what i have measured..the value was decided by Douglas Self...you can see the same value in his Blameless...this amplifier started copying the blameless and then tweaking it.... it is not too much different...since the very beginning i had troubles......i think was the transformer... i could not use the CCS to the VAS.... was a hell on earth..fuses burning...transistor overheating...oscilation i think...i had not time enougth to scope the thing before it has burned.
I cannot make statements based, or explained in theories...i do not know most of them..also, for a destiny accident, i do not like them..... if i do not like them because i do not know theories is possible...also that i do not like then because they have not helped me too much.... all results i can post are observation of what's happened.
Sorry, you may want me to produce some tests..... i understand you may not be too much happy with me....i may do some tests, not all them, i have already explained, i have another priority than to inspect this transformer..there are a lot of things i want to make in advance..will be doing, some tests, slowly.
Dear Mooly, you are always friendly...will eat more chicken...less cow beef.
regards,
Carlos
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Ahh... the good old days of front porches and sandcastle pulses.
The TV and repair trade (you were on the engineering side... transmission ?) gives a good background... you see faults and strange things all the time. I spent many years as a bench engineer in the repair trade 🙂
Your findings will be of interest.
The TV and repair trade (you were on the engineering side... transmission ?) gives a good background... you see faults and strange things all the time. I spent many years as a bench engineer in the repair trade 🙂
Your findings will be of interest.
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