Dx Blame ST - Builder's thread - post pictures, reviews and comments here please.

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I do not think he intended to say this way dear Wahab

I know Omar very well.... i am sure was not that way he posted...not the way you understood...language is a problem dear Wahab...Omar has Academic degree...he made College, he is a teacher...he works for a famous international company, he is respected in his place.... a highly intelligent man.

He knows that designers, to make a good job, needs to know everything....theories to support decisions, to know how to use simulator, must know how to use Distortion Analiser, Spectrum Analiser, function Generator and Osciloscope (at least these ones), to be skilled constructing things and knowing tips and tricks too.... good if the one is old enougth....good if had study in schools of electronics and in College too... good if has other electronic knowledge, alike some basic knowledge of Digital Electronics, also Radio Frequency, also video...the more the guy knows, more complete he will be.

He may intend to say the one have practice can do things, and make it work...the ones only have book knowledge can think about.

He may intend to say that the one has all the knowledge written above, may have some advantage compared to Academics..

He is thinking alike me....you can plug a book in the outlet..it will not play music....say...theories only,.... this does not play music..needs an amplifier..needs someone skilled and able to hold soldering iron and transform ideas in reality...producing things!...... both are important..but better if we can have one guy doing both things... a more complete man i think.

You are an example Wahab...you know how to build..you are a builder, also have college degree...so... you know that you have advantage compare to the ones knows to solder only..and advantage when compared to the ones knows to design only... do you remember the 220 ohms resistance you got fast, first, and correct.... that after a lot of research and calculations i found your value perfect?

Practice gives you more tools....if you want to tune an amplifier...you can solder a trimmer or padder... a variable capacitor, you can adjust, listen and inspect in the scope...others does have this solution...they will calculate and will believe the result of calculation will work great....the first will guarantee the unit will be tuned..the other will "believe" it will be.

I have to thank you Wahab...you gave me support...you where fair and above your feelings..we had our disagreements..and even this way you was superior...you found that was not fair to go villifying uncle charlie and you have posted....thank you...you are a real man.... we find friends in places we have never imagined.... the ones use to say are my friends, a lot of them.... said anything... the one had to punish me, i am sure, made it with broken heart..others, some close friends, felt nothing.

John Blackburn said that missed me....Omar said that hate sinbin singy... Anatech said i should have made something correct, because my amplifier was working...niss_man (Simon)... and few others, gave me some support too...i would like to thank you all.

Omar said that simulators does not plays music... he is rigth..we have to listen to evaluate..simulator produces graphics and numbers only.... indicates that may be good..but cannot guarantee.... ears will check the stuff.... audio is for humans... we could never see Scope and Generators going shopping audio amplifiers.... music is not for them... simulators cannot listen and evaluate..they are just machines..software running...just tools!

We do not see equipments shopping (sketch) because audio amplifiers was not make for them.... they were made for the audio amplifiers...tools only!

regards,

Carlos
 

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Wow , catching this late , a lot has happened here i see ..... :(

"Experience is what we gain when we do the work, Knowledge is what we gain when we read the book "



Metal could you please give us more details on your DX amp , what are you listening to it on ? is your speaker 8 ohm or 4 ohm? estimated power output?
 
It is fine..... the amplifier goes clipping when we drain 2.4 amperes to each rail

You see dear Meanman...this means 35V multiplied by 2.4A to each rail...or 84 watts consumption to each rail...means 168 watts both rails.

This simple calculation is because power is the result of the multiplication of voltage by the current... we have calculated above each rail power..then we have to add to know both rails power.

The calculation take into account the voltage you have in iddle...the real thing is that you may loose, at least, 5 percent.... some transformer may have bigger voltage drop...maybe 10 percent and i could find 15 and 20 percent too... depending how huge the unit is....so... the power consumption will not be that big Meanman...in the reality will not be...first because you have not continuous tone...so...your supply voltage will be "fluctuating"... the voltage will have constant overflow...may reduce to 31 Volts each rail while playing loud....with music that has a lot of bass..... this way you current will not be 2.4 anymore too...maybe 2 amperes...the consumption will be 120 watts total...i really think your transformer, if can supply your with 160 watts, will do a very good job into these amplifiers.... you may not have full 100 watts, as this depends on fixed supply voltage..and this does not happens in real life.... also... real life music is average... you will not reach the maximum power while listening normal music....maybe with distorted guitars full volume, or synthetizer...some Hammond Organ playing.... or feedback from microphone....but normally not.

When people wants to have exactly that 100 watts, they should select transformer that will supply 200 watts or more (reserve of power)...and also reserve of voltage (30 plus 30 volts AC transformer...200 or 250 watts unit)... a bigger transformer, with bigger power and bigger voltage, will give you more DC voltage...maybe 42 Volts.... and this will face the normal voltage drop when operating....so..you will have 35 or more volts to each rail while operating....your peaks of power will be higher than 100 watts... your average wil be higher too... and you will operate the amplifier using the real voltage the one was designed....compensating the normal voltage drop this way...increasing the voltage in a such way when reduced by the consumption will reach almost 35V as designed.

The amplifier can operate using 42 volts without problems.... condensers should be substituted by 50 volts units only... even BD139 will survive as i have tested them here with 55 volts...but...people can substitute BD139 by MJE15034 if they feel some scare about the BD139... to the drivers you can use MJE15034 and MJE15035....please, avoid MJE340/350...they are easy to oscilate..good but dangerous transistors.

BD139 can face 80 volts...and 42 volts supply (voltage without audio entering..this voltage is only stand by voltage) will not produce more than 80 volts peak to peak....also the transistor has 80 volts as "guaranteed" voltage..it has not a zener inside to drain if you have 81 volts applied.... the factory had guaranteed 80 volts...but this does not mean it cannot face 83 or 84 volts without problems.... well.... the supply will drop down..and the transistor will not have rail to rail voltage bigger than 70.... dinamically will never face 80 volts or more...... repeating...i have an amplifier using 55 volts... working...normally..and inside there are BD139/140 in the driver position and in the VAS position.

Theories says cannot work with more than 80 volts..but we should make interpretation, to engage brain and think about...if has a zener and the unit will be self destroyed if you hae 81 volts for instance applied in these units...if the voltage is absolute alike SOA...or if it is a guaranteed voltage... a reference voltage....or something they can publish (we guaranteed the transistor will survive at least with 80 volts)...this means can go more!

So...you can use 42 volts...no modifications....a good idea may be use the stronger MJL4281A and complementary...well..it is indicated anyway, because it is huge and was tested too.

The amplifier shown in the video is a Dx Blame ST, working with 55V supplies, with 2 output pairs for safety reasons.... and operated with 4 ohms speaker...so.... this was the torture.... and survived!... real test..real life test is a guarantee of reliability, even when using higher voltage than indicated.

"Reserve of quality and reliability"

http://www.youtube.com/watch?v=6T58F3PkD-Q
http://www.youtube.com/watch?v=nYbiN1CQNQE
http://www.youtube.com/watch?v=DynJ8yKHCXI
http://www.youtube.com/watch?v=QNjZKbz3YL8

regards,

Carlos
 
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........................i have an amplifier using 55 volts... working...normally..and inside there are BD139/140 in the driver position and in the VAS position.

Theories says cannot work with more than 80 volts..but we should make interpretation, to engage brain and think about...if has a zener and the unit will be self destroyed if you hae 81 volts for instance applied in these units...if the voltage is absolute alike SOA...or if it is a guaranteed voltage... a reference voltage....or something they can publish (we guaranteed the transistor will survive at least with 80 volts)...this means can go more!
I have tried so hard not to enter any of DX originated threads since his return, but I can't let this passage go without comment.
Theories do not say "cannot work with more than 80 volts".
The datasheet from the manufacturer says that the device will be reliable if you follow their recommendations for use.
That is not "interpretation" nor "engage brain", that is reading what the manufacturer is telling the customer.

I can't explain the reference to "zener" in a BJT.

Look at the ONsemi BD140 datasheet. It shows a graph in fig1 titled Active-Region Safe Operating Area.
Does it say the device will go "poof" if the Vce is taken above 81Vce? I can't see that confirmation.
Now SOA @ 25degC shows the BD138 & BD140 can pass a continuous 75mA when Vce=50V. It also shows that the same devices can pass a single shot transient that is much higher than the DC rating. They quote 140mA for 5ms and 600mA for 100us, both at Vce=50V.
The duration and repetition have an enormous effect on the maximum stress the device can take. This one example shows that at 25degC and 50Vce that the device can pass between 0A and 600mA dependent on the type of signal that is passed.

I cannot see where the manufacturer says his devices "can go more"

As for "we guaranteed the transistor will survive at least with 80 volts", I read this as saying the manufacturer guarantees that if you don't abuse the device one can expect a normal rate of failure of just a few in a thousand (or maybe better) and that that rate of failure will increase with time. It is also implied that abusing the device or taking it outside it's SOA that the rate of failure will increase. It is not a guarantee that no device will ever fail.
 
Of course AndrewT, the ones does not want to abuse

them will not do that way...no one have the power to force them to do that way... the ones does not want to take the risk, then they can use MJE15034 and MJE15035 or others, alike 2SC4793 and it's complementary... and this was suggested...read the text.

The amplifier is rated to 35 volts and can face 42 volts supply without problems as i have tested here.

The use of 55 volts is an exception, not a rule, this amplifier is asked to work with 35 volts as you can see in the schematic diagram.

I am just informing folks they can feel safe with 42, as i have tested with 55V. and i have tried two different brands of BD139/140.

No one is saying data sheet is wrong or they are lying, i am say we must engage out brain to make some interpretations, not only to read...the engagement means to think about after you read descriptions... we need that... a fast reading may not inform the power transistors dissipation was measured with the transistor keept at 25 degrees celsius...so.... that 250 watts we see in datasheet is not the real thing..we have to read with care, the small lines...this is "the brain engagement" to think about if we gonna have all that dissipation in our homes, in my home the environment temperature is 30 degrées average..not 25 degrées celsius..also, i cannot keep these transistors in a stable temperature..only factory can do that...so...this is what i mean...not only to read..to think about... we will never reach all that dissipation in real life use...so... we have to make interpretations, not only go reading without make reflections about.... this is what makes human different from computers...machines read things..we think about.

No one is stimulating builders to use 55 volts...my torture test was made to drive them confident the unit have suffered torture, so..if they decide to use 41 or 41 volts, they will not be scared... the schematic has printed 35 volts.

No one force you to read my threads Mr. AndrewT, this is up to you...if you dislike, well, better to be happy not reading them.... i will forgive you in advance, as you will loose the chance to learn something from the other side of the knowledge, the practice side.... the nice adventure to know what happens in real life...say...outside the book.

I think it is not a good idea to me to be reading your posts, as they use to give me some work, to produce work explaining you such things we all know and you may know too...so... spending my time with that is not a good thing...i have other amplifiers and other things to do...anything uncle charlie post is product of "belief"... it is all tested, and videos prove that...so..it is diferent than beliefs... it is real world..reality.

My farewell ...you have uncle charlie's blessings to leave this thread if you want....have a good trip to the happy side of the forum not reading Uncle Charlie tested foolishes;)

There's a unsubscribe button somewhere..just click there and Uncle Charlie will disappear from your life.

Carlos
 
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Hey Andrew, mine worked with +/-47V, but this is not safe. I listened to it for a couple of hours, no problems. But I did not want to mention this over here because it is not alright to do so as the datasheet suggested, I took the risk, and it is thundering. Still I don't recommend it, neither Carlos recommend it. It is against datasheet and is "not safe".

Calm down, don't push your self too hard to come here, whatever makes you think are welcome here Andrew?
 
I have been testing my amp today and am in need of help adjusting. On Gregs website it says to adjust the voltage across the 100ohm resistor to be between 3.3 - 6v or 33ma to 60ma standby current. After adjusting the voltage to 3.3v or 33mA standby current I place the fuses into the rails.

I have also checked the current across the power transistors or Ie. I have seen somewhere that this should be around 10mA Ie. Mine is 17mA which equates to .6w wasted each transistor or 1.2w total.

Should I be adjusting only the voltage across the 100ohm resistor to 3.3v or should I adjust so the power transistor Ie is 10mA.
When I adjust so that Ie is 10mA across power transistor emiter, the voltage across 100ohm res drops to around 2.2v which is under the recomended 3.3-6v.

What needs to be done?
 
Adjust to obtain 4.7 volts reading over the rail series protective

resistances.

This adjustment was modified listening... was a tuning made by German group...some Germans also uses 7 to 8 volts.... this is a result of listening tests.

Do not worry about the current measured over the power transistor emitter resistances...check only the voltage over the rail resistances and adjust them to 4.7 volts and be happy.

regards,

Carlos
 
4.7v over 100ohm resistor it is then.
resistances.

This adjustment was modified listening... was a tuning made by German group...some Germans also uses 7 to 8 volts.... this is a result of listening tests.

Do not worry about the current measured over the power transistor emitter resistances...check only the voltage over the rail resistances and adjust them to 4.7 volts and be happy.

regards,

Carlos
 
Here you have high resolution, high quality recordings in FLAc you

can download for free....the quality is excelent..and the amplifier that shows that quality is the Dx Blame ST and ES.

When i play MP3 320K or Flac in other amplifiers, i feel the same quality..as amplifiers are not able to show the difference.

But when i play MP3 320K or Flac in the Dx Blame i feel strong emotions..the music came alive and they enter my room and play in front of me!...the difference is clear and the superiority of Flac encoding and the Dx Blame is evident.

Download here..it is for free...i think was Gaetan that found that and sent me:

Ryan Adams Live at Das Haus on 2006-10-17 : Free Download & Streaming : Internet Archive

So...enjoy the difference.... "Vive la differènce!"

Dx Blame ST brings the band into your home!

regards,

Carlos
 
Be prepared Castro!...be aware you will experience new emotions!

The first second this amplifier will play your prefered music, will bring you the magic experience to be teletransported to the site it was previously recorded... you will feel the brigth, transparent and present sound in your body hairs...your bones and your breast case.

Satisfaction guaranteed!

A really mature amplifier.... awsome sonics..... plays loud and clear, precise and almost perfect.

Do you have something in your home, an old amplifier or something alike?....have room in your closed to locked it in?... you will not listen it anymore...you gonna be playing the Dx Blame ST and will not tolerate others anymore.

I am disconneting my own Troyan....nice and good sonics the Troyan.... super powerfull..the house is shacking..windows shacking, doors, keys, cell phone moving over the table...i am afraid to have cracks in my wall...i am felling the huge power in my body....but the monster is submerged in deep shame when compared with the Dx Blame....no chance to the Troyan.... no chance....the life performance from the Blame, the emotions are unbeatable.

Doctor Self made a really great job, i do think amplifiers inspired on his design may sound very good after some tweaking...the original sounded stérile..... very good but clinical, alike a steak not well fried, an almost crude piece of meat, also not having salt enougth.... you know, that bloody piece of junk, a bad prepared steak ..cold..not soft and not tasty.

I put the spice on it...some grey pepper.... the correct portin of salt.....i left the steak to burn a little to produce a toasted cover.... was fried in butter...that brown burned butter that taste and smell great!..... the Blame is alike a well fried steak..soft and tender, rose colour inside... dark brown toasted outside...and goes perfect with fried potatoes, or immaculated white rice....together an ice cold Coca Cola!... got it?.... got the feeling?...the sensation?

I am proud..very proud..unabashedly happy as have cooked that steak!..i have made the Blame even better compared to the original..i am owned by the splendor of having achieved something special while burning my finger, as i had overcome my own prejudice about this amplifier i had assembled several year ago, when i found it a piece of junk...i changed my mind, now i think the opposite.. i'm deeply happy that i have found the one!... the first and the best audio amplifier in my point of view, that made me confident to say to brazilians that i gonna eat it if loose in a comparative.....i do think i left my finger print in the audiophile communitty that will never be removed.

Prepare yourself for strong emotions.... have a good company, a nice woman... the one you love please..that one and no other!, a good food, have a nice and fresh shower and dress your best shirt... a confortable shoe..or better to remove the darn shoe.... and prepare yourself to dance with the rithm.

See the picture, even a dead one can return from the thumb, and ressurrect to dance together the magic of this lovely Dx Blame ES and ST amplifiers!

regards,

Carlos
 

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