Pery.... i am just avoiding to say what i think...to let people
cooperate with ideas.
But, in advance, not beeing too much arrogant, i know exactly the sonics this will produce.
I have already watched this "movie"....so...i know how the movie ends.
I will try...of course i will do...but the chances are small, even tuning the resistance...18 ohms, 20 ohms, 22 ohms...result will not be good.
thank you Pery.
Isso vai soar mau que nem bufa dentro de elevador...this will sound so bad as someone producing annoying noises inside a crowdy elevator.
We will see that.
regards,
Carlos
cooperate with ideas.
But, in advance, not beeing too much arrogant, i know exactly the sonics this will produce.
I have already watched this "movie"....so...i know how the movie ends.
I will try...of course i will do...but the chances are small, even tuning the resistance...18 ohms, 20 ohms, 22 ohms...result will not be good.
thank you Pery.
Isso vai soar mau que nem bufa dentro de elevador...this will sound so bad as someone producing annoying noises inside a crowdy elevator.
We will see that.
regards,
Carlos
I really feel that VAS limiting will be audible at lower, safe volumes. I cannot answer for the Baker clamp, haven't heard them, but I understand they are widely used on very powerful amps.
Since Carlos' amp is just 60W, I don't feel it's needed here, though I realise lots of people will disagree, but that is their prerogative.......
So I reckon this amp is ready to roll - more power to Carlos!!
Hugh
Since Carlos' amp is just 60W, I don't feel it's needed here, though I realise lots of people will disagree, but that is their prerogative.......
So I reckon this amp is ready to roll - more power to Carlos!!
Hugh
The site below is a help for beginners (like me) who would like to know what is CCS , VAS , and many other details of a power amplifier design:
http://members.tripod.com/valveaudio/Membuatsendiri.htm
http://members.tripod.com/valveaudio/Membuatsendiri.htm
Thank you Hugh... i do think in the same way... you have agreement.
I think will disturb sonics.. i am near to be sure...of course, near future, i will check that, will adjust to avoid that...i will bias in a better point to avoid sonic disturbance.
But as you see... i cannot imagine those circuits without disturb..they are clear a disturbing...of course...they limit...audio will be limited..this will appear into dinamics.
Diodes also limits, depending the way you install them... but also they clip the wave shape... this one compresses.
Alike automobile and trucks speed limiters...they do the job, but truck and car performance goes down.... they are breaks!
This protection seems to me:
- "You fix here to destroy performance there"... not a very good result.
regards,
Carlos
........................................................................................................
Pery
I can help, a little, and in our own language if you need some.
Beeing inside my knowledge you can ask me directly
Qualquer coisa estou na área...agora menos ocupado um pouco.
I am around, needing some help.... now i am less busy.
Doubts to direct mail:
panzertoo@yahoo.com
regards,
Carlos
I think will disturb sonics.. i am near to be sure...of course, near future, i will check that, will adjust to avoid that...i will bias in a better point to avoid sonic disturbance.
But as you see... i cannot imagine those circuits without disturb..they are clear a disturbing...of course...they limit...audio will be limited..this will appear into dinamics.
Diodes also limits, depending the way you install them... but also they clip the wave shape... this one compresses.
Alike automobile and trucks speed limiters...they do the job, but truck and car performance goes down.... they are breaks!
This protection seems to me:
- "You fix here to destroy performance there"... not a very good result.
regards,
Carlos
........................................................................................................
Pery
I can help, a little, and in our own language if you need some.
Beeing inside my knowledge you can ask me directly
Qualquer coisa estou na área...agora menos ocupado um pouco.
I am around, needing some help.... now i am less busy.
Doubts to direct mail:
panzertoo@yahoo.com
regards,
Carlos
Hi Aska,
The current limit is *not essential* but might be worthwhile to cover use with a wider range of available devices.
Hi Carlos.
The present HR has a current limit on the +ve going output, this being the bootstrap chain @ ~10mA. However, there is *no* current limit on the -ve going drive where the VAS transistor could momentarily saturate and pull 100mA through the base of the PNP driver under overload conditions !
Thus there is a greater chance of sonic disturbance when playing loudly without a current limit fitted.
With 22 ohms in its emitter lead the VAS can control output stage driver transistor input through +/-10mA without triggering the current limit transistor. This would be normal full output. Until the VAS emitter current exceeds 20mA, the current limit transistor cannot influence reproduction.
I noted Nordic's comment to 'the two of us', and I am not wishing to argue with anyone. However, my suggestion has been argued against, so I merely point out the circuit operation.
This is a minor point in relation to sonics, but could influence reliability and reputation. There is nothing more embarrassing than an amplifier failing when someone else runs it very loudly, especially with young-uns who tolerate output clipping as part of the 'sound'.
Cheers ........... Graham.
The current limit is *not essential* but might be worthwhile to cover use with a wider range of available devices.
Hi Carlos.
The present HR has a current limit on the +ve going output, this being the bootstrap chain @ ~10mA. However, there is *no* current limit on the -ve going drive where the VAS transistor could momentarily saturate and pull 100mA through the base of the PNP driver under overload conditions !
Thus there is a greater chance of sonic disturbance when playing loudly without a current limit fitted.
With 22 ohms in its emitter lead the VAS can control output stage driver transistor input through +/-10mA without triggering the current limit transistor. This would be normal full output. Until the VAS emitter current exceeds 20mA, the current limit transistor cannot influence reproduction.
I noted Nordic's comment to 'the two of us', and I am not wishing to argue with anyone. However, my suggestion has been argued against, so I merely point out the circuit operation.
This is a minor point in relation to sonics, but could influence reliability and reputation. There is nothing more embarrassing than an amplifier failing when someone else runs it very loudly, especially with young-uns who tolerate output clipping as part of the 'sound'.
Cheers ........... Graham.
I understood, it is clear Graham...the negative going to hell
Guys working into clipping can kill the lower driver and lower output.... all rigth.
I will do the testings, and will make my strongest efforts to produce the VAS protected that will not bother sonics.
But i will not do that fast, not now.... i want to let room to our friends to construct, to keep Nordic board as standard and not changing nothing.... giving to people a stable amplifier related schematics, not a mutant that we never know what will happens tomorrow.
Off course, the first that had output burned, than, as a fire soldier, to extinguish fire, we will introduce the protection, into the schematic, as an emergency solution till i do the testings or other one does....real testing...burn testings... sacrifice of one output pair in the name of the reliability.
I will keep...will hold...will maintain, with all my forces and efforts, the amplifier, the way it is today, to have more constructors...and i want to do that for 3 monthes minimum time since the High Resolution II schematic was published.
Well..if emergency comes...Ecat, or Nordic with burned output.... not fake outputs, not beeing errors of constructions, shorts caused by the constructor or something that killed the amplifier... reinforcing the idea that this VAS may be dangerous...than....we will move fast.
regards,
Carlos
Guys working into clipping can kill the lower driver and lower output.... all rigth.
I will do the testings, and will make my strongest efforts to produce the VAS protected that will not bother sonics.
But i will not do that fast, not now.... i want to let room to our friends to construct, to keep Nordic board as standard and not changing nothing.... giving to people a stable amplifier related schematics, not a mutant that we never know what will happens tomorrow.
Off course, the first that had output burned, than, as a fire soldier, to extinguish fire, we will introduce the protection, into the schematic, as an emergency solution till i do the testings or other one does....real testing...burn testings... sacrifice of one output pair in the name of the reliability.
I will keep...will hold...will maintain, with all my forces and efforts, the amplifier, the way it is today, to have more constructors...and i want to do that for 3 monthes minimum time since the High Resolution II schematic was published.
Well..if emergency comes...Ecat, or Nordic with burned output.... not fake outputs, not beeing errors of constructions, shorts caused by the constructor or something that killed the amplifier... reinforcing the idea that this VAS may be dangerous...than....we will move fast.
regards,
Carlos
Dear Nordic, adjust your trimpot to 5K
This will keep around 700 microamps to each differential transistor.... this is to use with those transistors into the differential colectors.
If you decide to try resistances, then you will see how usefull will be trimpot.
regards,
Carlos
This will keep around 700 microamps to each differential transistor.... this is to use with those transistors into the differential colectors.
If you decide to try resistances, then you will see how usefull will be trimpot.
regards,
Carlos
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Hey Graham, it was more of a joke....... Ideas need to be discussed freely if we want to make "better" future versions
Thanks Uncle Carlos...will dial in 5k.... I have one more 5k pot...
Do you use the mutiplier or just resistances.... ?
P.S. If my dvd player didn't damage the amp, I doubt anything short of hooking an active source like an electric guitar up, is not going to cause harm.
Thanks Uncle Carlos...will dial in 5k.... I have one more 5k pot...
Do you use the mutiplier or just resistances.... ?
P.S. If my dvd player didn't damage the amp, I doubt anything short of hooking an active source like an electric guitar up, is not going to cause harm.
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Yes....BC639 and BC640 (PNP) can be used into many positions
in this amplifier..... exception will be VAS and drivers.... they need more power.... working as VAS or driver those BC639 and BC640 will burn.
They are the same die of BD139 and BD140.... difference is the enclosure only...same transistor, dissipation reduced because small transistor...also maximum current...but all data may be the same.
They are good, but, as you know, they do not have 350 of gain...this makes difference too....also they have different construction, the base is not into the center, this will create a lot of errors...because of those things i did not have used those ones.
Send me a message.... i want you adress once more.... problems here with my adress list...using new browser Nordic...even an empty message will be good....needed is your adress...but pictures are good too...hehe
regards,
Carlos
in this amplifier..... exception will be VAS and drivers.... they need more power.... working as VAS or driver those BC639 and BC640 will burn.
They are the same die of BD139 and BD140.... difference is the enclosure only...same transistor, dissipation reduced because small transistor...also maximum current...but all data may be the same.
They are good, but, as you know, they do not have 350 of gain...this makes difference too....also they have different construction, the base is not into the center, this will create a lot of errors...because of those things i did not have used those ones.
Send me a message.... i want you adress once more.... problems here with my adress list...using new browser Nordic...even an empty message will be good....needed is your adress...but pictures are good too...hehe
regards,
Carlos
Thanks uncle Charly, I will temporarily use it then, as it seems to be the only component missing, to finish this board... I saw from the datasheet I will have to bend the first pin to act as pin 3... will use some heatshrink on the pin for isolation...
The first time I powered up I got this transistor the wrong way around.... it poped open in 2 halves.. no I know what they look like inside.
The first time I powered up I got this transistor the wrong way around.... it poped open in 2 halves.. no I know what they look like inside.
Oh!... envy!!!...envy!!!... we have not heatschrink tubes here.
I knew them because of Sony Japan..but here....hummm...have not.
All rigth Nordic...go ahead..they will play a good sound too.
Well..you know..those folks goes more than 100 Megahertz..hehe...this can be a problem..also capacitance to those folks are not the best ones...but will work.
I am starting to arrange things...electronics already half way organized.
regards,
Carlos
I knew them because of Sony Japan..but here....hummm...have not.
All rigth Nordic...go ahead..they will play a good sound too.
Well..you know..those folks goes more than 100 Megahertz..hehe...this can be a problem..also capacitance to those folks are not the best ones...but will work.
I am starting to arrange things...electronics already half way organized.
regards,
Carlos
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I'll get my wife to make you a christmas card with some.... I'm getting quite addicted to the stuff... have many difirent diameter ones....
Baah my input stages survived me putting in the single to92 in the wrong way around... blowing the sc5200, blowing both drivers... all my fault, not the amp's... you gotta learn somewhere... I learn by reading, and breaking stuff...
Baah my input stages survived me putting in the single to92 in the wrong way around... blowing the sc5200, blowing both drivers... all my fault, not the amp's... you gotta learn somewhere... I learn by reading, and breaking stuff...
My VAS is this...my VAS is that...it is small..not a good VAS
My VAS will burn.... Vas will go negative..ahahahhaa.
to compensate my frustration....will eat more today.
My VAS is all rigth... but a good reason to eat Chocolate Cake.
Of course kidding.... Vas is working folks!
regards,
Carlos
My VAS will burn.... Vas will go negative..ahahahhaa.
to compensate my frustration....will eat more today.
My VAS is all rigth... but a good reason to eat Chocolate Cake.
Of course kidding.... Vas is working folks!
regards,
Carlos
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I do not use BC639, despite they work fine, because i use to invert them and burn
a lot of transistors.
My name "destroyer"... was elected because of that.
You have learned, dear Nephew...not a good idea to use BC639...we use to do those things...very normal...very common.
Also..never switch power one without protective resistances and fuse into the output...to avoid shorts into the output because of our own mistakes.... the fuse will save the speaker...i have already burned many....now i have learned that speaker and fuse are something matched, married..they have always to be together.
regards,
Carlos
a lot of transistors.
My name "destroyer"... was elected because of that.
You have learned, dear Nephew...not a good idea to use BC639...we use to do those things...very normal...very common.
Also..never switch power one without protective resistances and fuse into the output...to avoid shorts into the output because of our own mistakes.... the fuse will save the speaker...i have already burned many....now i have learned that speaker and fuse are something matched, married..they have always to be together.
regards,
Carlos
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