Dx Blame ES .... based into the Blameless, i am trying a new amplifier

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Poison is for me, never mind my dear

She looks that is criticising the schematic diagram, latine root languages can be this way...electric layout not good can be understood and designer made ship....you know, the way the circuit was arranged, how was connected, the technicall decisions..not the board, not how it looks...layout for latine root people can be understood, also, as a draw, a sketch, the topologie....things alike this...not sure about her intentions, but looks criticism, a clever one, no one can judge, as can be several things.

hehehehe... she looks likes me, but i have not made what she want me to do..this is the main trouble.

I have not followed all her instructions... so, may not be too much happy with me.

Your work, your board, your layout is BEAUTIFULL, very professional and no one is crazy to criticise, as this will look super stupid to the one try to do that.

But a poor simple guy, that have learned burning fingers, well, this one can receive some shots.

No problem, i have a shield (big belly holds punches)

regards,

Carlos
 
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Your work, your board, your layout is BEAUTIFULL, very professional

Ha ha. Yeah, it's a breathtaking work of art. The Mona Lisa of PCB layouts. :crazy: I'll call it "Frameless".

Seriously, I want to know how to improve these type of layouts. Is anything too far away from anything else, too close to anything else, tracks too long, tracks too parallel, too narrow, too wide, more ground, less ground, etc.

..Todd
 
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Yes John, we all know she use to help, also that she is very skilled

no doubts about that, reason why i use to accept, from time to time, things that looks rude...well.... looks rude, but we never know if this is a consequence of our latine language english version, say, the language, can make that.

Husband and wife...this is very rude in my language...we do not call this way..never!, it is extremelly rude, is "esposa"

Young girl, using the mother language, the Portuguese from Portugal is "rapariga", here this means prostitute.

Sakis is very friendly with me, but his posts are smashing, really rude, i think his mother language may be too much direct, some short way to speak.

I have born, and educated in a French town, we had french invasion in Rio, and their we have created a new way to talk, longer but more kind.

We do not say:

- Will not rent the appartment for you

We would say:

- We are trying to find solutions for some bureaucratic troubles we are facing, and these things are, now a days,a impeachment for use to rent the appartment to you, we hope we gonna find a way to find the best solution for both of us, ... you that want to rent and we that have the mission to rent that appartment.

Use of language, one is hard and direct, other is easier and left one door opened behind, a possible future negotiation, a hope.

regards,

Carlos
 
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That friend that is building several Dx Blame ES boards, and now using the correct

dimensions, not more enlarged, felt the absence of the " L " shape adaptor terrible.. i do think the same...the transistors, the power ones, with their long legs seems Octopus attacking the board parts.

Carlos
 

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The problem, dear Taj, is we can turn ourselves obsessive doing that

and this finishes beeing a "never ending story"

I really think that some basic things must be used, and i suppose they are enougth.

Avoid too much long lines, copper lines

Avoid lines too much close one related the other when they run in parallel, as this produces a capacitor, the two lines are the two poles, the capacitor electrodes

We need thick copper lines where we have high current, a large one to the drivers and a even larger one to the power output colectors.

IF we have to decide to go surrounding the board to connect two parts, better use a jumper than to run long run of copper track.

Lines in parallel must be avoided, in special if too much close, 1 milimeter width track and 2 milimeters with free space in between..yes, this enlarges the board.

Copper lines in parallel are capacitors...long copper lines are inductor...when we have inductor and capacitors, we have tuned circuits, if this value is big, then the frequency is low and can reach 100 Megahertz.... transistors can oscilate, or operate, in this frequency, so, if we offer these ressonant parts, and the transistor can work, for sure they will work and oscilate... in a ressonant circuit, when you reduce the capacitance or the inductance, the frequency goes up, this means goes to 300 megahertz..... transistors (normal ones) cannot work in 300 megahertz, and because of this they do not oscilate..because they cannot..board will offer ressonance, but they will not oscilate..the cannot!

Ground place is nice, but seems a small capacitor in all connections (0,1pf), depending the connection, you must put the amplifier to oscilate in the place to stop it.

Lines crossing is much better than parallel, despite ugly they are better, so, jumpers we hate are the best solution.

Input must be very distant from output, to avoid coupling.

Some parts, as electrolitic condensers or other coiled capacitors, generates electro magnetic fiel surrounding them...if you install a condenser too much close to another, you may pick and this means trouble... and this was the reason why Japanese stopped to make things too much small, when small you reduce length, but increase coupling.... they were clever, they used transistors that could not operate in Very High Frequencies (VHF), this way they have avoided oscilations and they have increase board length...in the past (sixties) parts are so nearby one each other that seems was glued..and some really used some glue to make easier to invert the board to solder without having parts falling down.

These basic rules are enougth to be rid (free) of troubles.

Nothing is perfect, so the board you feel perfect today you will find errors tomorrow..i Michelangelo was obsessive this way, doing and doing again, and making it better..maybe no frame was ready his entire life..we must be carefull about that..time matters too...life goes fast to be wasting too much time with a single board, better to make several.

regards,

Carlos
 
Then in 1980 the troubles return to our lives, amplifier less stable once again

Someone, do not know where, had the inspiration that very high speed transistors applied to audio frequencies (imagine that, 200 Megahertz transistor used to work in 20Khz)... they said the square wave rising time was smaller, the slew rate very big, to make the square wave better.

But we do not listen square wave!... audio is not square wave, of course shows harmonics, of course is a hard signal to be amplified with precision and of course shows some qualities from the amplifier you are measuring.

But, we do not even listen square waves, we have mechanical to electro chemical processing, it is slow, reason why you burn your finger and you feel that several miliseconds after the burning starts...the delay, what the delay does to a square wave?...you can imagine what enters our brain.

This means. why worries about square wave, we do not even listen them as square waves..inside the brain, what enters the brain is not a square wave!, the rising time is slow, it is more a cutted peak mountain, a not tall mountain, more alike a sinus!

But they enter that new tech moment, the high speed transistors were used and the sonics became awfull, harshing, tiring....we could not be listening for too long...those High Speed Kenwood were a tragedy in sonics during the early eigthies (my personnal opinion), the ones that used the big transistors, those green ones the dutch has a lot (people say they are keept hidden inside the matress, he sleep with these transistors and never use them, do nto give them and do not use them....the dutch...you know the one i am talking about..that lovely crazy dutch)

To avoid these things to oscilate they were overcompensated, sound was not fine..so, to be stable, they have made a slow down into earlier stages, because in the first chance the units started to oscilate triggered by the signal, that oscilation superimposed to the horizontal portions in the square wave observed in the scope display.

MJE340/350 are terrible, i have lost several because of oscilations...and i could not even notice while they were starting the self suicide, as i use BD139/140 that are very stable, i was not worried about the VAS, using already some overcompensation, a big miller there..and i was having fun doing some research, some tweek, some tries in prototypes..without worries about the VAS stage, as worked fine with BD139 without troubles AND using smaller capacitor..then the crazy transistors overheated oscilating, i have not perceived what was happening, they gone!... paft!

I do think that some "inspirations" would be better if was "perspirations", some hard work and swet can fast show you that some inspirations are harmfull, the use of radio frequency transistors, in audio amplifiers was a tragedy, a terrorism against our ears.

regards,

Carlos
 
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Why this happened and more clever folks have not go against that?

I was thinking those last years about that and two cultural things shows me the answer.

In Recife, one of the oldest towns in Brazil, people developed an idea that you cannot eat pig meat when you have diseases, in special when you have scares, or wounded, or cuts in your skin... they use to say the pig meat helps infection, that it is infected by itself...that is dangerous, can be bad, may kill you...and toaste desinfecte salted meat is told this way!

But in other towns people does not think this way.... but even Doctors here say that..when the one goes to the Doctor and ask if can eat pig meat during his disease, while is inside the healing process, the doctors says NO!

Why they say no?

That belief is so strong in my culture, say, this town, this state, that if you decide to go against will face reactions, the people will say you are not a good doctor, that you know nothing, that you are stupid...you will lost the confidence from others, they will not trust in you and you will not have more people to help with your Medicine expertise...so, social forces..social pressure.... social myths and beliefs...not technically well explained.... food when enters stomach and receive acids,dissolved,diluted, became chemical products, hard to detect if that meat was from pork or not..just carbon, salts, grease, iron an other things, no one having the name "pig" printed on it.

In Rio de Janeiro people may remove the glass having Mango fruit mixed with milk,,,aqnd with violence!...this is to save your life (Ice cream has Mango with Milk an no one says a word against)..they say you gonna die drinking that.... you see... try to say the opposite!, they will say you are mad, crazy, someone that scaped from a Psycho hospital!. This happened during the slave times.... early morning, the slaves that use to collect milk from cows to latter produce cheese, use to drink more than half the milk together Mango they collected from trees, mango here is alike grass, Mango trees is everywhere, they fell down over your cars..they stay in the streets pavement till people remove the trash (hehehehe)... this was bad for the farmers.... ONE day, one slave died, and he have eated a lot of Mango with Milk..the clever farmer said Mango with Milk kills..then this was spread into whole town and whole state...now a days a Doctor, even knowing this is foolish, if you ask him, he may say cannot eat Mango mixed with milk.

So, this happened in eighties with our beliefs.... the rule was:

low speed is bad!, high speed is good!, good square wave is sign of good audio reproduction, slew rate must be enormous...and so happened, even not beeing truth, happened, because we are humans, we are social, we live in groups, we want to be accepted and respected and the group use to create it's rules.

Dx amplifiers, all them, works better when using lower speed transistors, square wave is good, but even beeing not perfect, i am sure you will appreciate the sonics.

regards,

Carlos
 
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There's always something we can do to make a good thing becomes even better

You see, transistor holes when triangle shape, not aligned, not in a line (strip) form, is much better, you solder and the transistor remains in the position,... tripod is a better support.

So, we can go producing modifications to make things better, but is good not to exagerate, or we will never finish things.

regards,

Carlos
 

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Bending the leads of a transistor too close to the body may result in early failure, particularly in an unbranded part like this.

btw: I have used these transistors that are labeled "CBC" in pink noise generators with quite a lot of success, parts from On-Semiconductor and other known brands didn't produce enough noise 😀

Be aware that this is not usually manufactured to BC546 specs, it's just a generic die labeled BC546, it could be BC547, 548, 549, 550, or even 639 and 337... Capacitances, Ft, noise, and beta are uncontrolled.
 
I prefer SMD transistors because the TO-92 and TO-126 market is flooded with generic dies with unpredictable performance labeled as whatever you are expecting to get, because the original parts are usually discontinued by almost all the reputable brands that were making them 10 or 20 years ago.

Our lovely BC546/556, BC547/557, BC550/560, BD139/140 almost no longer exist.

I still keep some dozens from On-Semi and Philips that sometimes I use for breadboarding things before they become SMD (and also many dozens of generic/fakes).
 
I still keep some dozens from On-Semi and Philips that sometimes I use for breadboarding things before they become SMD (and also many dozens of generic/fakes).


the BD139/140 pair from philips is the best one,
with a typical Ft of 160 mhz at 100mhz frequency test..
if you have some left, better to not waste them,
they deserve to be implemented in high perfs amps..
 
I love those BD139, and i have more than 20 pairs ready to use

It is hard to see and use and solder SMD, seems i will need special solder to flow more, maybe lower temperature solder, or the one keep melted for longer time maybe, special tools, hot air maybe...well...it is a technology very modern to my gray hairs... to see them, read them, i need special magnified lenses to work with them, and a third hand or tripod to hold the magnified lenses for me..... very different way to do things.... will be strange alike learn to walk once again.

These transistors, the old BC standard series, BC547,557,546,556... also BD139/140... these ones we find here everywhere, all shops have these ones, they are alike Volkswagen beetle during the seventies, you could find them everywhere... they are very cheap 6 for a dollar the small ones and 80 cents of a dollar BD139/140.... we do have also 2N3055, made by an old computer company that used these transistors, there are stocks of them, despite were made down the eighties.... were used in ancient supplies to computers... easy to find, alike Coke.

Will finish someday, but no troubles about that, there are several substitutions, BC847 is one we can use, well, we can use a couple of thousand models that will have almost same gain, same maximum voltage, almost the same graphic of transference, same maximum frequency, power dissipation and maximum current.

I do not think/believe, Brazilians will give up to transistors soon, my people do not trust in "black boxes", when burn you loose the entire black box, also you do not know exaclty what is inside, you cannot modify an stage for instance... also Fets are not popular, only the ones used to fix PC supplies.

We have and we had factories, from Phillips , Texas and some others here, so, if market ask more, we gonna have more.

Of course SMD invaded, but, people still prefer units that has more discrete and less computers, they do not buy Aiwa systems anymore, they are buying some Sony Receivers and Philips systems that love to use discrete...my Class D system is full discrete in the power amplifier, only the headphone amplifier is made by small smd chip.

We think, me and my friends, the audio group, that has people of several ages, the smd and chips are made to work for some time only, disposable gods, while discrete is for life.... audio is passion and we do not want passion for a week long... good passion is the one burns alike fire resting for all life long.

regards,

Carlos
 
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Very pretty and shinning boards dear Rudi, Mr. Vice President from the Corporation,

German International division.

I am glad you are here, showing your enthusiasm and pictures dear Rudi, send the best regards to dear Volker.... and the other one, i think his name is Juergen, also Christian and all member of your lovely meeting group for audio evaluation and testing.

regards,

Carlos

regards,
 
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