Heatsink temperature changes, depending the environment temperature
the type of audio program and the volume you use... the VBE multiplier is there to compensate, to control the stand by bias.
When heatsink goes too much hot, them the VBE multiplier senses and voltage from colector to emitter is reduced, this way reducing the iddle current to the output...when this happens you will measure different voltage in the series protective resistances used to adjust stand by bias.
Heat reduces transistor internal resistance, this increases current, and increasing current you have as a consequence heat increasing.... but the VBE multiplie... reduces, so you may have a small modification in your reading... depending how good is your VBE multiplier thermal tracking... the resultant can be more or less different than the cold measured current.
AB current use to be small, but we can increase the way we want, the way we feel the sound result better ... a good idea is to check having a very low volume to see if you are not underbiasing, also the check emitter resistances (power) to be sure power transistors are conducting..and then go incresing, while listening, till you find the sound better..... till 100 miliamperes is considered normal and very standard, but this does not mean you cannot go higher than that..it is up to you, and may obbey your ears, your own evaluation about.... 100 miliamperes, or a 10 volts reading over the 100 ohms series resistance, means you will be wasting 7 watts as heat, during stand by..... it is fine, as some class A dissipates 200 watts during stand by.
The suggested current, to start up, is 3.3 to 4.5 volts measured over the protective resistance, this means the waste will go from 2 to 3 watts... depending your selected and adjusted voltage..but this is a suggestion only....just as start up..then the owner take their own decisions about.
You may find the same iddle current for years long, maybe for a decade, or 10 years latter, if you measure the amplifier cold, early morning, and if your home temperature is stable...then you will measure the same.
6 hours latter, after sunrise, if your home changes temperature (not having automatic thermal control, heater or these things) then you measured stand by current may be sligthly different.
I also do not like heat, as when we notice the heatsink is 45 degrees celsius, this means the junction may have higher temperature while transfering heat, so, there are peaks of temperature in the junction and this may reduce the transistor life..... transistor use to be alive or dead...and when goes hot can die ....but this does not happens when cold....will survive you, your sons, your grandsons, and so on.
All i do i use to keep human body temperature when iddle, i do not accept hot amplifiers...class A is not for me...i really do not like the idea of waste all that power if we can do things different.... better to accept some crossover distortions (Class AB) to have low power and enormous heat inside your home.
Heat can be good for Europe, when you have snow and cold, but here...heheheh.... is a suicide.
Perfectionists, the ones loves precision, may feel bad with analogic audio amplifiers, as one day you may measure 3 milivolts in the output (offset) and the other day you may measure 5 or 1 milivolts.... this use to show you overflow also, and if you do not short the input, then the amplifier shows higher overflow depending the input sensitivity.... also mains voltage variates, temperature variates..... readings goes variating too.
I am sorry, really sorry to have to comment these very basic things, some between you may feel offended as you may think i have the belief you do not know these things.... not reality, i believe 99 percent know that deeply, the problem is the resting one percent, not knowing can be confused in in panic start to spread posts that may discourage beginners to build..... i am explaining to that 1 percent, to avoid them to create distrust about an amplifier... and they do that not because they are bad, they do because they feel scared with these unexpected (for them) things.
Each guy that write:
- "I felt something wrong with this or that"
results in 3 guys that give up (more or less...in my imagination....happened this way those last days) to build.... three of them confirmed that has worries, feel scared about the bias.
regards,
Carlos
the type of audio program and the volume you use... the VBE multiplier is there to compensate, to control the stand by bias.
When heatsink goes too much hot, them the VBE multiplier senses and voltage from colector to emitter is reduced, this way reducing the iddle current to the output...when this happens you will measure different voltage in the series protective resistances used to adjust stand by bias.
Heat reduces transistor internal resistance, this increases current, and increasing current you have as a consequence heat increasing.... but the VBE multiplie... reduces, so you may have a small modification in your reading... depending how good is your VBE multiplier thermal tracking... the resultant can be more or less different than the cold measured current.
AB current use to be small, but we can increase the way we want, the way we feel the sound result better ... a good idea is to check having a very low volume to see if you are not underbiasing, also the check emitter resistances (power) to be sure power transistors are conducting..and then go incresing, while listening, till you find the sound better..... till 100 miliamperes is considered normal and very standard, but this does not mean you cannot go higher than that..it is up to you, and may obbey your ears, your own evaluation about.... 100 miliamperes, or a 10 volts reading over the 100 ohms series resistance, means you will be wasting 7 watts as heat, during stand by..... it is fine, as some class A dissipates 200 watts during stand by.
The suggested current, to start up, is 3.3 to 4.5 volts measured over the protective resistance, this means the waste will go from 2 to 3 watts... depending your selected and adjusted voltage..but this is a suggestion only....just as start up..then the owner take their own decisions about.
You may find the same iddle current for years long, maybe for a decade, or 10 years latter, if you measure the amplifier cold, early morning, and if your home temperature is stable...then you will measure the same.
6 hours latter, after sunrise, if your home changes temperature (not having automatic thermal control, heater or these things) then you measured stand by current may be sligthly different.
I also do not like heat, as when we notice the heatsink is 45 degrees celsius, this means the junction may have higher temperature while transfering heat, so, there are peaks of temperature in the junction and this may reduce the transistor life..... transistor use to be alive or dead...and when goes hot can die ....but this does not happens when cold....will survive you, your sons, your grandsons, and so on.
All i do i use to keep human body temperature when iddle, i do not accept hot amplifiers...class A is not for me...i really do not like the idea of waste all that power if we can do things different.... better to accept some crossover distortions (Class AB) to have low power and enormous heat inside your home.
Heat can be good for Europe, when you have snow and cold, but here...heheheh.... is a suicide.
Perfectionists, the ones loves precision, may feel bad with analogic audio amplifiers, as one day you may measure 3 milivolts in the output (offset) and the other day you may measure 5 or 1 milivolts.... this use to show you overflow also, and if you do not short the input, then the amplifier shows higher overflow depending the input sensitivity.... also mains voltage variates, temperature variates..... readings goes variating too.
I am sorry, really sorry to have to comment these very basic things, some between you may feel offended as you may think i have the belief you do not know these things.... not reality, i believe 99 percent know that deeply, the problem is the resting one percent, not knowing can be confused in in panic start to spread posts that may discourage beginners to build..... i am explaining to that 1 percent, to avoid them to create distrust about an amplifier... and they do that not because they are bad, they do because they feel scared with these unexpected (for them) things.
Each guy that write:
- "I felt something wrong with this or that"
results in 3 guys that give up (more or less...in my imagination....happened this way those last days) to build.... three of them confirmed that has worries, feel scared about the bias.
regards,
Carlos
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To novice,the really beginners!
Thermal control, heat sensor, VBE multiplier or any type of control cannot make miracles, even an enormous fan cannot help if you have small heatsinks to your power ratio...also the VBE multiplier transistor, the thermal sensor unit, must be attached to the heatsink, using insulator if needed and thermal compound.
Bad use, amplifier exposed to sunligth, amplifier covered with another amplifier, cloth over the amplifier ventilation grid..... in other words, all impeachment to convection cooling may destroy your amplifier.
To use undersized heatsinks, 4 ohms loads, continuous steady tone, square waves continuously and in the maximum power, may destroy your transistors if they are overheated....also harmonics generated when you overdrive amplifiers using square waves, will kill your tweeter, as it will receive not more 10 percent (more or less) or the entire audio program power, they may receive 80 percent this way.
Tweeter use to be low power...in a 100 watts speaker enclosure you may have a 60 watts bass driver, a 30 watt midrange (squawker) and a 10 watt tweeter..this was used in the past and i suppose they continue to do this way because this makes sense and saves money, as factory does not imagine someone will play distorted square waves, continuously, full power, if they are healthy in their minds.
A big trouble will be find the one is perfectly healthy.... i am not!
ahahahahahah!
regards,
Carlos
Thermal control, heat sensor, VBE multiplier or any type of control cannot make miracles, even an enormous fan cannot help if you have small heatsinks to your power ratio...also the VBE multiplier transistor, the thermal sensor unit, must be attached to the heatsink, using insulator if needed and thermal compound.
Bad use, amplifier exposed to sunligth, amplifier covered with another amplifier, cloth over the amplifier ventilation grid..... in other words, all impeachment to convection cooling may destroy your amplifier.
To use undersized heatsinks, 4 ohms loads, continuous steady tone, square waves continuously and in the maximum power, may destroy your transistors if they are overheated....also harmonics generated when you overdrive amplifiers using square waves, will kill your tweeter, as it will receive not more 10 percent (more or less) or the entire audio program power, they may receive 80 percent this way.
Tweeter use to be low power...in a 100 watts speaker enclosure you may have a 60 watts bass driver, a 30 watt midrange (squawker) and a 10 watt tweeter..this was used in the past and i suppose they continue to do this way because this makes sense and saves money, as factory does not imagine someone will play distorted square waves, continuously, full power, if they are healthy in their minds.
A big trouble will be find the one is perfectly healthy.... i am not!
ahahahahahah!
regards,
Carlos
Attachments
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Hi Carlos long time no see
i got a little suggestion
- remove socket ( the thin make your amp sound a liitle bit hard )
- remove fuse
- try to found elna elect caps for supply
- change the ceramics resistor with wirewound
Perfect Sound will be come to your Ears
Rgds, jeff
i got a little suggestion
- remove socket ( the thin make your amp sound a liitle bit hard )
- remove fuse
- try to found elna elect caps for supply
- change the ceramics resistor with wirewound
Perfect Sound will be come to your Ears
Rgds, jeff
Thank you Pocoyo..your suggestions will be tried in the next model
The one will be released March,28..... IF, sound really better than this one offered for our forum.
Your suggestions will be tried, will be installed, will be listened, and will be used if change something in sonics or in the scope waveform.
regards,
Carlos
The one will be released March,28..... IF, sound really better than this one offered for our forum.
Your suggestions will be tried, will be installed, will be listened, and will be used if change something in sonics or in the scope waveform.
regards,
Carlos
Hello Luka,
what type of capacitor are you using as the input cap (C1)?
Is it a non-polarized one?
Best regards - Rudi_Ratlos
what type of capacitor are you using as the input cap (C1)?
Is it a non-polarized one?
Best regards - Rudi_Ratlos
Dx blameless excellent audio.😀
adjustment bias is to 63ma on each side of the source and off set 0.12mv the circuit and very stable. 🙂
adjustment bias is to 63ma on each side of the source and off set 0.12mv the circuit and very stable. 🙂
Very good Beto..thank you very much.
I am happy it is stable the way you did...long wires to power transistors use to unstabilize...and this have not happened...so, the amplifier is stable.
Long wires under the board, sometimes unstabilizes too....and it is stable even this way.
Thank you very much, was good to know that.
And there we go with our basic english, and communicating perfectly..our school basic english.... "The book is on the table"..... goooood!
Nice resistances you have... the standard colour code.... i do not like the chinese ones with that crazy colour code and the blue base colour.
regards,
Carlos
I am happy it is stable the way you did...long wires to power transistors use to unstabilize...and this have not happened...so, the amplifier is stable.
Long wires under the board, sometimes unstabilizes too....and it is stable even this way.
Thank you very much, was good to know that.
And there we go with our basic english, and communicating perfectly..our school basic english.... "The book is on the table"..... goooood!
Nice resistances you have... the standard colour code.... i do not like the chinese ones with that crazy colour code and the blue base colour.
regards,
Carlos
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We have already more than 10 units built and working fine
this is a very good start....in two years, we gonna have more than hundred!
Good that... all over the world...from Alaska to Patagonia.... from Russia extreme North to New Zeland..... all continents..... this will be Dx invasion, a peacefull and pleasant invasion, bringing you pleasure and good moments.
Yessssss.... this makes me feel good.
regards,
Carlos
this is a very good start....in two years, we gonna have more than hundred!
Good that... all over the world...from Alaska to Patagonia.... from Russia extreme North to New Zeland..... all continents..... this will be Dx invasion, a peacefull and pleasant invasion, bringing you pleasure and good moments.
Yessssss.... this makes me feel good.
regards,
Carlos
Attachments
The ones have build, the majority are Brazilians, and very close friends
reason why the popularity.... the ones have built:
Sergio Vaz - Brasil
Renato Comerlatte (2)- Brasil
Me (3) - Brasil
Egberto - Brasil
Beto - Brasil
Funky2x _ Syria
Ekkart - Germany
The ones are still building:
Luka from Polland
Rudi from Dx Corporation - Germany
And there are others that said will build.... when someone from US build..then a lot will come too..and then my beloved country, the Star and Stripes country, will be playing Dx amplifiers too... also, if someone from the "hermanos" countries, the spanish language countries that are neighboors from Brasil, just one, and then, several "hermanos" will build too.... i need just one to give the happy example!
Wait, for next monthes, the miracle of multiplication, the "divine" amplifier will be multiplied!
Dear Rudi will go using his happy submarine.
regards,
Carlos
reason why the popularity.... the ones have built:
Sergio Vaz - Brasil
Renato Comerlatte (2)- Brasil
Me (3) - Brasil
Egberto - Brasil
Beto - Brasil
Funky2x _ Syria
Ekkart - Germany
The ones are still building:
Luka from Polland
Rudi from Dx Corporation - Germany
And there are others that said will build.... when someone from US build..then a lot will come too..and then my beloved country, the Star and Stripes country, will be playing Dx amplifiers too... also, if someone from the "hermanos" countries, the spanish language countries that are neighboors from Brasil, just one, and then, several "hermanos" will build too.... i need just one to give the happy example!
Wait, for next monthes, the miracle of multiplication, the "divine" amplifier will be multiplied!
Dear Rudi will go using his happy submarine.
regards,
Carlos
Attachments
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Er, Carlos ?
Which is the definitive schematic for the DX Corporation Blameless amplifier ?
I want to build a 50w stereo to compare with my old Kyocera receiver, and am mulling over your design, Steve Dunlap's Krill, or the Viscode design that uses a complementary/cascode Darlington input stage.
Which is the definitive schematic for the DX Corporation Blameless amplifier ?
I want to build a 50w stereo to compare with my old Kyocera receiver, and am mulling over your design, Steve Dunlap's Krill, or the Viscode design that uses a complementary/cascode Darlington input stage.
Well.... i am sad about Kyocera...was a very good amplifier before faced the Dx Blame
About my friend, the one made Krill, a very good amplifier (I had off set) and this other one..... i think will be better not to comment,.... they are friends..you will know the amplifier is the best.
In this thread, go back and read and you will collect the last version, also you can go to Greg Erskine home pages, there are some dedicated to the Dx Amplifier.
But i would like to suggest you not to compare with your Kyocera if it is heavy to transport to the junk box.
I would like to say, that 10 guys have assembled and two have faced problems....read the entire thread.
Greg's Web Site
ahahahahahah!
Er,... to you too man!
Carlos
About my friend, the one made Krill, a very good amplifier (I had off set) and this other one..... i think will be better not to comment,.... they are friends..you will know the amplifier is the best.
In this thread, go back and read and you will collect the last version, also you can go to Greg Erskine home pages, there are some dedicated to the Dx Amplifier.
But i would like to suggest you not to compare with your Kyocera if it is heavy to transport to the junk box.
I would like to say, that 10 guys have assembled and two have faced problems....read the entire thread.
Greg's Web Site
ahahahahahah!
Er,... to you too man!
Carlos
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Cleaning the PCB
... with ISOPROPANOL 70% (Do NOT drink 😀) and tooth-brush:
Very important! Wipe away grease and solder flux!
I will be back, Carlos, if I get my own BlameES running - or vanish forever!
Rudi_Ratlos - Ex-Vice-Admiral of DX Corp. Intl. German Division
... with ISOPROPANOL 70% (Do NOT drink 😀) and tooth-brush:
Very important! Wipe away grease and solder flux!
I will be back, Carlos, if I get my own BlameES running - or vanish forever!
Rudi_Ratlos - Ex-Vice-Admiral of DX Corp. Intl. German Division
Vanish forever not fine!...board is not the same!
Please, if have troubles, them build Taj board... and remove extra circuits.
ahahaha..if worked fine with small distance lines, then you have fun with me.. saying your inductive and capacitive board worked, that i do not know these things, that you was write and i was wrong.
Well.... Volker boards were made this way too...so....your one will work too..i am already prepared, with the back sit against the wall,
Well, i will be so happy if you suceed that i will not bother if i was rigth or wrong
ahahahahahah!
regards,
Carlos
Please, if have troubles, them build Taj board... and remove extra circuits.
ahahaha..if worked fine with small distance lines, then you have fun with me.. saying your inductive and capacitive board worked, that i do not know these things, that you was write and i was wrong.
Well.... Volker boards were made this way too...so....your one will work too..i am already prepared, with the back sit against the wall,
Well, i will be so happy if you suceed that i will not bother if i was rigth or wrong
ahahahahahah!
regards,
Carlos
Attachments
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People does not understand why brazilians are so happy
Here you see my daugther (one of them..ahahahaha!) , and also other girls...my daugther is the left one in the group.
With this weather, with these lovely girls.... we cannot be sad..it is impossible!
Daugther will be married soon..also will come to see me before the marriage, to ask me to get married.... she has 27
regards,
Carlos
Here you see my daugther (one of them..ahahahaha!) , and also other girls...my daugther is the left one in the group.
With this weather, with these lovely girls.... we cannot be sad..it is impossible!
Daugther will be married soon..also will come to see me before the marriage, to ask me to get married.... she has 27
regards,
Carlos
Attachments
I was about to make a joke prizing the quality of the "bottom end" of Brazilian amps 😀
but I prefer to remain silent, he, he
M
but I prefer to remain silent, he, he
M
Be confortable to say whatever you want...these amplifiers are absolutelly ridiculous
I hope they (forum folks) do not confuse these amplifiers quality with my beloved amplifiers, this is the only risk, to confuse me with my country amplifiers.
I have learned from this forum, so my know how comes, mainly, from this place...this forum,
I am glad and sad to know i have more knowledge than my people, in special the ones are not designing amplifiers here..they should, but they are not. this is a shame...really i feel very bad with enormous disconfort about this.... they copy even the resistance values from Marshall Leach.... also the board number ID.
I do not know about modern, very new designs, but i have strong suspections they are doing the same using chips in the input or error correction...so, a make up from the double simetrical amplifier, the full simetrical, these one use double differential, one PNP and other NPN.
Ridiculous.... problem is they may think i am so retarded that way.... retarded to be copying in the place to be calculating.
I do search and researches to make my franksteins, i am always scanning (50 years long) amplifiers made everywhere, building testing and arranging, forcing to work and comparing, i am not only copying the way my people use to do.
About "bottom end"..for sure i understood you..but daugther will not feel happy watching these kind of comments, she is very decent and serious, will not be happy people watching only her bottom end.
She had only two boy friends whole life, and even to married she will come to present the guy and to ask me permission..so...as you see... so decent as your family... the one i know as very decent.
But really... this we have.. a lot of bottom end........ amplifiers and much more.
regards,
Carlos
I hope they (forum folks) do not confuse these amplifiers quality with my beloved amplifiers, this is the only risk, to confuse me with my country amplifiers.
I have learned from this forum, so my know how comes, mainly, from this place...this forum,
I am glad and sad to know i have more knowledge than my people, in special the ones are not designing amplifiers here..they should, but they are not. this is a shame...really i feel very bad with enormous disconfort about this.... they copy even the resistance values from Marshall Leach.... also the board number ID.
I do not know about modern, very new designs, but i have strong suspections they are doing the same using chips in the input or error correction...so, a make up from the double simetrical amplifier, the full simetrical, these one use double differential, one PNP and other NPN.
Ridiculous.... problem is they may think i am so retarded that way.... retarded to be copying in the place to be calculating.
I do search and researches to make my franksteins, i am always scanning (50 years long) amplifiers made everywhere, building testing and arranging, forcing to work and comparing, i am not only copying the way my people use to do.
About "bottom end"..for sure i understood you..but daugther will not feel happy watching these kind of comments, she is very decent and serious, will not be happy people watching only her bottom end.
She had only two boy friends whole life, and even to married she will come to present the guy and to ask me permission..so...as you see... so decent as your family... the one i know as very decent.
But really... this we have.. a lot of bottom end........ amplifiers and much more.
regards,
Carlos
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