I have learn in other forum, that some rubber, antivibrating may stop ringing...ahaha
Also that ceramics from Stuttgart makes chips sounding more treble.
Having fat aluminium panels, the sound will turn fat...with "body"
If you put resistor directly over the chip, the electrons that are tired, will have easier chance to move.
That some fat electrons are good because use jeans pants, that's the reason why the electron tube has that blue ligth.
If you use a 100 Amps. power supply, amplifier will drain more and more current, and will be more powerfull...ahahahahahah!
Have to clean all board twice..... to have clean highs!
If nothing of that produce the result...blame the factory!.....hummmm the chip was defective!
And this was not captured in the Chip forum....nothing from our guys.... someone told me, in confidential mail....ahahahahahha.
World is wonderfull...people are very interesting.
But do not forget...using some precious wood to construct amplifiers,not only the sound will turn "precious", but also will damp the speaker ressonances....something connected to wood respecting the other wood!
I was forgetting he also said...but as a secret...so...do not talk other forum guys...rigth?.... that he is Napoleon Bonaparte...that he had some drug, and have much more than 100 years old...much more!
This i did not agree!.....as I AM NAPOLEÓN.... i was kidnnaped by an Orion space craft and i returned last years.....i land directly in the middle of this forum!
regards,
Carlos
Also that ceramics from Stuttgart makes chips sounding more treble.
Having fat aluminium panels, the sound will turn fat...with "body"
If you put resistor directly over the chip, the electrons that are tired, will have easier chance to move.
That some fat electrons are good because use jeans pants, that's the reason why the electron tube has that blue ligth.
If you use a 100 Amps. power supply, amplifier will drain more and more current, and will be more powerfull...ahahahahahah!
Have to clean all board twice..... to have clean highs!
If nothing of that produce the result...blame the factory!.....hummmm the chip was defective!
And this was not captured in the Chip forum....nothing from our guys.... someone told me, in confidential mail....ahahahahahha.
World is wonderfull...people are very interesting.
But do not forget...using some precious wood to construct amplifiers,not only the sound will turn "precious", but also will damp the speaker ressonances....something connected to wood respecting the other wood!
I was forgetting he also said...but as a secret...so...do not talk other forum guys...rigth?.... that he is Napoleon Bonaparte...that he had some drug, and have much more than 100 years old...much more!
This i did not agree!.....as I AM NAPOLEÓN.... i was kidnnaped by an Orion space craft and i returned last years.....i land directly in the middle of this forum!
regards,
Carlos
I do not constructed using the board...my output coil is in the opposite side related
Input....my army Seargeant...Ottmar Albert Furrer, from Sweden, that turn Brazilian because interested my government had on him....gênius he was..... he told when he remove the pipe from his mouth.
"My dear Carlos.....be attention and never forget....output cannot be near the input...if you can...put input in North pole and output in south pole"
Please Carlos...can you repeat to me what i have said!
Well...i have this in memory...i use to tell others....but they do not care.
There are "very good, skilled, intellectual, PHD, Doctored, experienced"...that do not believe in magics....as well i do not believe in "some" magics too......what can i do?
nothing!
regards,
Carlos
Input....my army Seargeant...Ottmar Albert Furrer, from Sweden, that turn Brazilian because interested my government had on him....gênius he was..... he told when he remove the pipe from his mouth.
"My dear Carlos.....be attention and never forget....output cannot be near the input...if you can...put input in North pole and output in south pole"
Please Carlos...can you repeat to me what i have said!
Well...i have this in memory...i use to tell others....but they do not care.
There are "very good, skilled, intellectual, PHD, Doctored, experienced"...that do not believe in magics....as well i do not believe in "some" magics too......what can i do?
nothing!
regards,
Carlos
Carlos,
it oscillated without output coil, to no load.
This is not about belief, but measuring the phenomenae. The oscilloscope is a must to be able to say anything, no experience can substitute it.
The basic point is to be able to distinguish between magic and science. That's why pseudoscience in audio is so popular - most people cannot tell the difference.
it oscillated without output coil, to no load.
This is not about belief, but measuring the phenomenae. The oscilloscope is a must to be able to say anything, no experience can substitute it.
The basic point is to be able to distinguish between magic and science. That's why pseudoscience in audio is so popular - most people cannot tell the difference.
Carlos,
you wanted for me to make an independent analyse. In fact it seems it is the last thing you really wanted. Look at your posts about Hermann, his dog, cold electrons in Eastern Europe, doctors, PhD etc. Really very valuable and "friendly" posts (you expect you are friendly, don't you??). What are you trying to do?
you wanted for me to make an independent analyse. In fact it seems it is the last thing you really wanted. Look at your posts about Hermann, his dog, cold electrons in Eastern Europe, doctors, PhD etc. Really very valuable and "friendly" posts (you expect you are friendly, don't you??). What are you trying to do?
Try a ferrite bead in one of the transistor leads....as cannot be bad, use it in all
Transistors.... the base is better because sensitive...those ring ferrite beads that you know.
I was kidding Pavel.... do not take serious...having fun!, to reduce the frustration i am feeling, the damned work you are having....so...i invited you not to test (that is really happening is different), you are repairing the unit for us....and this was not my intention when invited you.
To produce job for you..... responsability to fix..... you can stop when you decide to....to not bother yourself to fix that, as you have to take care of your family first!..... finish the construction and evaluate the sound, and that will be much more than i hope for, and finished, the waveform and sound reproduction will show,and will appear something, that is consequence of the oscilation...will be good to know how this amplifier will sound with this problem....maybe the same as driff, will confirm what we are supposing related his problem and helping him too.
We want to know, is that:
If you like the amplifier or not?
If even having this small amplitude oscilation, if the amplifier is good?
Can be much better without that oscilation that appeared?
Mine is sounding good....have not oscilation!....many others too!
Of course you already check if not capturing your instruments clock oscilators...the VTVM, Scope or some Radio Frequency generator you may have..... the computer also..... swith all home off...only scope and amplifier....well...you already done that..for sure!
Do not loose patience with me....i do not deserve, only because kidding....kick the amplifier, as it is only a board and some pieces of metal...This amplifier is not a representative of my value or my honor, or Michael's honor.... and not your honor too.... a hell with it if disturb you life and produce in yourself some bad feeling, or disconfort, working with feaver....forget that thing...life is better!
Let's have a beer...or mineral blue bottle water my dear.
regards,
Carlos
Transistors.... the base is better because sensitive...those ring ferrite beads that you know.
I was kidding Pavel.... do not take serious...having fun!, to reduce the frustration i am feeling, the damned work you are having....so...i invited you not to test (that is really happening is different), you are repairing the unit for us....and this was not my intention when invited you.
To produce job for you..... responsability to fix..... you can stop when you decide to....to not bother yourself to fix that, as you have to take care of your family first!..... finish the construction and evaluate the sound, and that will be much more than i hope for, and finished, the waveform and sound reproduction will show,and will appear something, that is consequence of the oscilation...will be good to know how this amplifier will sound with this problem....maybe the same as driff, will confirm what we are supposing related his problem and helping him too.
We want to know, is that:
If you like the amplifier or not?
If even having this small amplitude oscilation, if the amplifier is good?
Can be much better without that oscilation that appeared?
Mine is sounding good....have not oscilation!....many others too!
Of course you already check if not capturing your instruments clock oscilators...the VTVM, Scope or some Radio Frequency generator you may have..... the computer also..... swith all home off...only scope and amplifier....well...you already done that..for sure!
Do not loose patience with me....i do not deserve, only because kidding....kick the amplifier, as it is only a board and some pieces of metal...This amplifier is not a representative of my value or my honor, or Michael's honor.... and not your honor too.... a hell with it if disturb you life and produce in yourself some bad feeling, or disconfort, working with feaver....forget that thing...life is better!
Let's have a beer...or mineral blue bottle water my dear.
regards,
Carlos
Carlos,
I think Pavel can distinguish EMI from real oscillation...
An amplifier oscillating, even with few mv can not sound good !
You'll get exactly what Dimitris described.
I am very glad Pavel is caring, he is more experienced and has the better testequipment, and i am sorry that he stumbled into the problem with the Toshibas. He can't evaluate any audible qualities before having solved that problem, right now i can not help too much as i don't have the Toshibas, and will take some time to get some.
The guys building gainclones, what else than peeling the electrolytics and things like that can they do to improve the sound ? They can't open the chips and replace some silicon caps by micas... 😀
Mike
I think Pavel can distinguish EMI from real oscillation...
An amplifier oscillating, even with few mv can not sound good !
You'll get exactly what Dimitris described.
I am very glad Pavel is caring, he is more experienced and has the better testequipment, and i am sorry that he stumbled into the problem with the Toshibas. He can't evaluate any audible qualities before having solved that problem, right now i can not help too much as i don't have the Toshibas, and will take some time to get some.
The guys building gainclones, what else than peeling the electrolytics and things like that can they do to improve the sound ? They can't open the chips and replace some silicon caps by micas... 😀
Mike
Carlos,
thank you for clarification, which I was unable to find in the posts .. 😉
Back to oscillations - as you know, I do not have them if I keep Iq low. Any amp must not HF oscillate, as this is always timed bomb for the future. Several people confirmed the problem, especially dtrif, whose amp has almost gone for the oscillation problem. HF oscillations is a problem with which I am not able to live as a circuit designer. And they also do affect the sound.
I will do listening tests after I complete the 2nd channel and will play with stability for some time, it will be in 1 week or so.
Regards,
Pavel
thank you for clarification, which I was unable to find in the posts .. 😉
Back to oscillations - as you know, I do not have them if I keep Iq low. Any amp must not HF oscillate, as this is always timed bomb for the future. Several people confirmed the problem, especially dtrif, whose amp has almost gone for the oscillation problem. HF oscillations is a problem with which I am not able to live as a circuit designer. And they also do affect the sound.
I will do listening tests after I complete the 2nd channel and will play with stability for some time, it will be in 1 week or so.
Regards,
Pavel
Carlos,
in our communication I would greatly appreciate clear facta with evidence. If I have oscillations that start above Iq 25-30mA and increase with Iq to amplitude of 2V, then please do not try to speak about EMI. If it was 2mV, same for turned-off and turned-on amp, it would be another story.
Please never try to mystify or underestimate, as this would never help the circuit or product.
in our communication I would greatly appreciate clear facta with evidence. If I have oscillations that start above Iq 25-30mA and increase with Iq to amplitude of 2V, then please do not try to speak about EMI. If it was 2mV, same for turned-off and turned-on amp, it would be another story.
Please never try to mystify or underestimate, as this would never help the circuit or product.
My amps were built with the transistors as per the original schematic (p to p, as shown earlier in the thread) and biased per it also. I haven't had any obvious signs of oscillation, though my detection scheme is very crude - only my dull ears and AM radio close to the circuit. So I can't rule out oscillation but it can't be close to what Dimitris has found. (If I keep at this hobby I'll have to get a scope and learn how to use it.) Pavel, you haven't specifically mentioned the MJL3281/1302 type as being problematic. Is the difference in input capacitance between those and the Toshiba transistors sufficient to avoid the problem in your models?
Sheldon
Sheldon
Sheldon,
yes, the problem occured only for Toshiba 2SA1943/2SC5200 output devices. They are faster than Toshiba 2SA1302/2SC3281. The problem arose at me (I fixed with aid of oscilloscope) and dtrif (he almost lost 1 channel). Another problem was at jarkaa, his input about output devices would be appreciated.
I do not have MJL1302/3281, so I did not test them. When I did a recherché 3 years ago I found devices similar, but Toshiba 2SA1943/2SC5200 better.
I will compare in detail Toshiba and MJL datasheets for these different devices.
I have several ideas how to increase stability margin, but would probably loose some of symasym advantages.
Pavel
yes, the problem occured only for Toshiba 2SA1943/2SC5200 output devices. They are faster than Toshiba 2SA1302/2SC3281. The problem arose at me (I fixed with aid of oscilloscope) and dtrif (he almost lost 1 channel). Another problem was at jarkaa, his input about output devices would be appreciated.
I do not have MJL1302/3281, so I did not test them. When I did a recherché 3 years ago I found devices similar, but Toshiba 2SA1943/2SC5200 better.
I will compare in detail Toshiba and MJL datasheets for these different devices.
I have several ideas how to increase stability margin, but would probably loose some of symasym advantages.
Pavel
Yes, of course i recognize Pavel as an expert, reason why i invited him to evaluate,
as he can do a good job...and fast he could find something strange, a confirmation of his capacity to study those amplifiers deeply.
He obviously know EMI and Radio Frequency Interferences,he nows about detection, harmonics, parasitic capacitances, wire inductances and all those complicated things...i was just remembering, because i already had problems with that.
No problems to understimate or overstimate equipments...and i usually cannot do that...but this have connection to numbers....i am just a listener...i like the sound i am listening or i dislike, the reason why this happens, you all scientists will have the capacity to answer me......if i ask....because the most probable is that i will not ask....because really apreciating the sound, i will not care of what is going on in it's microcosmos.
regards,
Carlos
as he can do a good job...and fast he could find something strange, a confirmation of his capacity to study those amplifiers deeply.
He obviously know EMI and Radio Frequency Interferences,he nows about detection, harmonics, parasitic capacitances, wire inductances and all those complicated things...i was just remembering, because i already had problems with that.
No problems to understimate or overstimate equipments...and i usually cannot do that...but this have connection to numbers....i am just a listener...i like the sound i am listening or i dislike, the reason why this happens, you all scientists will have the capacity to answer me......if i ask....because the most probable is that i will not ask....because really apreciating the sound, i will not care of what is going on in it's microcosmos.
regards,
Carlos
Jarkaa used the MJL4281/4302, the high voltage brothers.
Hi Carlos, this is not really about numbers, but measuring shows flaws/errors, removing them always helps improving sound.
In this case it showed up that stability margin is too small, this could lead to instabilities by thermal variations or even aging...
Mike
Hi Carlos, this is not really about numbers, but measuring shows flaws/errors, removing them always helps improving sound.
In this case it showed up that stability margin is too small, this could lead to instabilities by thermal variations or even aging...
Mike
Sheldon and Michael,
the Toshibas have considerably lower Cob capacitance. That is good, but probably not for the symasym. I can try to get the devices to same league by putting 220 pF across Toshibas, but I don't feel good to try it, I will give back my supply rail resistors.
Pavel
the Toshibas have considerably lower Cob capacitance. That is good, but probably not for the symasym. I can try to get the devices to same league by putting 220 pF across Toshibas, but I don't feel good to try it, I will give back my supply rail resistors.
Pavel
All these transistors have approximately the same parametres, I had no problems with replacing Toshiba's instead Motorola's. But as I know, on the market are many plagiats....
Pavel - Yes, they have very similar parameters, with small exceptions, like Cob.
600pF for MLL,
200/360pF for Toshiba (same meas. conditions)
For amp with high stability margin this is probably no problem. For symasym that is "close to the edge" it may bring problems.
600pF for MLL,
200/360pF for Toshiba (same meas. conditions)
For amp with high stability margin this is probably no problem. For symasym that is "close to the edge" it may bring problems.
By my opinion isn't good to make amp close to edge. I was looking at Mike's schematic: 'cos output transistors have big " beta ", you can get there higher value of serial resistor ( 2R2 or 3R3 instead 1R2 ), which make amp more stabil. Also for stability is good give to the drivers CB's low value cap ( 22-33 pF ).
And still one notice : Is good connect in series with " rail " resistors 22 R diode - if one fuse blow and one of output transistors will be broken ( and output relay will be " off " ), on all structure of amp will be only one polarity voltage, which cause, that one of 100 M cap ( beside 22 R ) will explode, 'cos get reversal voltage.... 😉
Upupa Epops said:
Hi Upupa, yes you're right, i did not know that it is that close to the edge, i observed no problems with mine and so was happy !
I already suggested to dtrif increasing the basestoppers to the output-bjts. The drivers itself are stabilized by the 22ohms, removing them made them oscillate with 35mhz...
These high beta high speed devices are really a pain in the a.. !I ordered some Toshibas to be able to investigate...
Mike
This is disadvantage of constuctions for amateurs, Mike... People think, that sound depend on " superquality " of devices....Only some knows, that it depend also on other things... 😉