I do not agree Netlist...but i was a military, and as a soldier i use to obbey orders
If you want me to do this way..then i will give my best to read them.
regards,
Carlos
If you want me to do this way..then i will give my best to read them.
regards,
Carlos
"So I need not drive to Conrad tomorrow, Krachkiste, and can use my 16V caps?
Best regards - Rudi "
If thats the conclusion you draw for you from my measurement results, then you won't have to drive.
Do the measurement on your caps to see where they break through in reverse polarisation.
If this breakthough voltage (absolute value, no minus!) + the voltage rating of the cap (e.g. 16V) is sufficiently greater than the supply rail voltage you should be safe.
Best regards - Rudi "
If thats the conclusion you draw for you from my measurement results, then you won't have to drive.
Do the measurement on your caps to see where they break through in reverse polarisation.
If this breakthough voltage (absolute value, no minus!) + the voltage rating of the cap (e.g. 16V) is sufficiently greater than the supply rail voltage you should be safe.
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The very purpose of this forum is to learn from and help each other in this great art called audio.
If you want Personal Glorification from sheep-like followers, diyAudio is the wrong place to come to.
I want this nonsense to stop immediately.
/Hugo
If you want Personal Glorification from sheep-like followers, diyAudio is the wrong place to come to.
I want this nonsense to stop immediately.
/Hugo

Use 25 volts units Rudi....it is safe this way
Using 16 volts condensers will work too...because they can tolerate higher voltages than specified.
regards,
Carlos
Using 16 volts condensers will work too...because they can tolerate higher voltages than specified.
regards,
Carlos
Hi, Carlos, I'm also here to improve my skills regarding this wonderful amp!!!
I'm sure the study of this thread together with your tips at HTForum in Brazil, will help me to do a better job assembling my own DX Blame ST!!!
Regards and Grande abraço! rsrs
Adriano Dias
I'm sure the study of this thread together with your tips at HTForum in Brazil, will help me to do a better job assembling my own DX Blame ST!!!
Regards and Grande abraço! rsrs
Adriano Dias
Netlist,Using 16 volts condensers will work too...because they can tolerate higher voltages than specified.
is this the nonsense you want stopped?
before that K posted this
and followed up withA worst case scenario would suggest that the amp provides the full rail voltage constantly, thus confronting the series of C1 and C1* with this voltage.
and Rudi saysIn conclusion both caps have to be able to withstand at least the full rail voltage in this configuration.
What do we do with nonsense like this being advised to beginners who cannot yet know better?Thank you for your advise and best regards
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We all know (it has been pointed out a myriad times) that caps should not be used at higher voltages then rated. Nor should transistors or resistors or coils.
I see both sides, people who build and offer countless free hours and designs to the forum and others pointing at possible errors and flaws.
Its delightful to read a thread when both are symbiotic.
/Hugo
I see both sides, people who build and offer countless free hours and designs to the forum and others pointing at possible errors and flaws.
Its delightful to read a thread when both are symbiotic.
/Hugo
Aldotin, read the rules:
Threads about site moderation are not allowed and will be closed and deleted. Please handle questions and comments about how to improve the site or moderation via the "Report Post" button, PM, or the contact form.
/Hugo
Threads about site moderation are not allowed and will be closed and deleted. Please handle questions and comments about how to improve the site or moderation via the "Report Post" button, PM, or the contact form.
/Hugo
Thank you asdiax..... very kind your presence here
Friends we evaluate them in the bad moments..... i will memorize your presence my dear.
regards,
Carlos
Friends we evaluate them in the bad moments..... i will memorize your presence my dear.
regards,
Carlos
There's no technical error in my potentiometer...this was used in several
amplifiers...and they are working and no audio source was damaged...so....this is real world result..not "i think so" or "the book says"...a reality my dear friends .. this much more important than beliefs and some rigid rules....or status quo (stablishment)
If we go keeping ancient ideas without try options....criticising new ideas and approaches..them we would still believing the world is square...and beyong the horizon there are monsters that eat entire ships.
We usually do not keep the potentiometer cursor at ground...because this does not make sense...amplifier is to produce audio, so, at least you have some resistance to ground...and more than 100 ohms, usually does not let transistors burn... even if they have not DC blocking condensers..... you have always some resistance to ground.... this is real world practice...day by day real sittuation.
Muting circuits shorts output and stages to ground too without damage.... do not worry about that....people twist things and confuses because they want..if you think about you gonna see this is not that problem.
Also...you can install in a different way if you want....not with my blessing but you can of course... you're free to decide...up to you folks!
If you feel afraid..them install a series resistance into the potentiometer wipe, the cursor... them no short to ground will be possible...just that.
All that noise has other reasons than technicall perfectionism.... and all of you are watching this clearly.
regards,
Carlos
amplifiers...and they are working and no audio source was damaged...so....this is real world result..not "i think so" or "the book says"...a reality my dear friends .. this much more important than beliefs and some rigid rules....or status quo (stablishment)
If we go keeping ancient ideas without try options....criticising new ideas and approaches..them we would still believing the world is square...and beyong the horizon there are monsters that eat entire ships.
We usually do not keep the potentiometer cursor at ground...because this does not make sense...amplifier is to produce audio, so, at least you have some resistance to ground...and more than 100 ohms, usually does not let transistors burn... even if they have not DC blocking condensers..... you have always some resistance to ground.... this is real world practice...day by day real sittuation.
Muting circuits shorts output and stages to ground too without damage.... do not worry about that....people twist things and confuses because they want..if you think about you gonna see this is not that problem.
Also...you can install in a different way if you want....not with my blessing but you can of course... you're free to decide...up to you folks!
If you feel afraid..them install a series resistance into the potentiometer wipe, the cursor... them no short to ground will be possible...just that.
All that noise has other reasons than technicall perfectionism.... and all of you are watching this clearly.
regards,
Carlos
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are these optional to assemble power transistor below the board?
I think so...very clever decision from you and Omar...i really could not see these details when inspecting the board.
You include side holes for screws to... this seems optional not to hold the board by a "L" shape adaptor.
Congratulations Rudi and Omar.
You have made a really great job.
regards.
Carlos
I think it can be used to mount MT-200 shaped transistors, as the Sanken units.

Yes... i think so.... they had a good idea.... optional feature
So, the one want that or other way can make it .... both options.... "L" adaptor and no adaptor...Universal feature to all kind of taste.... transistor above, transistor below... power transistor connect using wires....so....very good that.
Congratulation Omar and Rudi
regards,
Carlos
So, the one want that or other way can make it .... both options.... "L" adaptor and no adaptor...Universal feature to all kind of taste.... transistor above, transistor below... power transistor connect using wires....so....very good that.
Congratulation Omar and Rudi
regards,
Carlos
Regarding C1 and C1* rated voltage, I would advise everyone to use 16V capacitors maximum, if you use electrolytic types.
I don't know if you are aware of this, but electrolytic capacitors only start working properly when they are under a voltage of at least 10% of it's rated voltage.
So, this capacitors are in series with the input signal. Considering a 1V RMS input, then it's much better to use a capacitor that's rated for 10V. Otherwise, proper functioning is not guaranteed.
Film capacitors don't show this behaviour, and are much better for audio portions of the circuit. Using film capacitors here is much better than electrolytic.
Again, don't use hihger voltage electrolytic capacitors for the input capacitors. Stay at 16V tops!
AndrewT can confirm what I just said.
I don't know if you are aware of this, but electrolytic capacitors only start working properly when they are under a voltage of at least 10% of it's rated voltage.
So, this capacitors are in series with the input signal. Considering a 1V RMS input, then it's much better to use a capacitor that's rated for 10V. Otherwise, proper functioning is not guaranteed.
Film capacitors don't show this behaviour, and are much better for audio portions of the circuit. Using film capacitors here is much better than electrolytic.
Again, don't use hihger voltage electrolytic capacitors for the input capacitors. Stay at 16V tops!
AndrewT can confirm what I just said.
Define "working properly"
The electrolytic caps I use all work to my satisfaction at every voltage from 0V to the voltage rating of the cap.
This youtube video shows what can happen if you stress a 10V rated cap to 22V.
YouTube - capacitor explosion 10V 220uF
There are lots of such videos.
If you like fireworks and the smell of sulfidic acid in your living room, listen to Mitchel.
The electrolytic caps I use all work to my satisfaction at every voltage from 0V to the voltage rating of the cap.
This youtube video shows what can happen if you stress a 10V rated cap to 22V.
YouTube - capacitor explosion 10V 220uF
There are lots of such videos.
If you like fireworks and the smell of sulfidic acid in your living room, listen to Mitchel.
krachkiste,
I never said to use a capacitor over it's rated voltage. In fact, you should always leave a safety margin of 20%.
What I said is that when you use electrolytic capacitors on signal path, considering that the signal is about 1V RMS, you should use the lowest voltage rated capacitor you can find, preferably 10V.
Don't you put words in my mouth, as I never said what you think I said ...
I never said to use a capacitor over it's rated voltage. In fact, you should always leave a safety margin of 20%.
What I said is that when you use electrolytic capacitors on signal path, considering that the signal is about 1V RMS, you should use the lowest voltage rated capacitor you can find, preferably 10V.
Don't you put words in my mouth, as I never said what you think I said ...
I can't....................... electrolytic capacitors only start working properly when they are under a voltage of at least 10% of it's rated voltage.
Can Anyone confirm what I just said?
I don't recall reading that in any manufacturer's datasheet.
Mitchel:
"krachkiste,
I never said to use a capacitor over it's rated voltage. In fact, you should always leave a safety margin of 20%.
What I said is that when you use electrolytic capacitors on signal path, considering that the signal is about 1V RMS, you should use the lowest voltage rated capacitor you can find, preferably 10V.
Don't you put words in my mouth, as I never said what you think I said ... "
The application we are talking about is Rudis DC protection. This protection must survive the conditions it is exposed to. In this case it is supposed to protect the speaker under all circumstances including the full rail voltage over these 2 caps. You say yourself, capacitors are not to be used over their rated voltage. Yet you propose to do so in this application.
Still, what is the explanation for that I "should use the lowest voltage rated capacitor you can find" in the context of your post.
What happens if I didn't?
"krachkiste,
I never said to use a capacitor over it's rated voltage. In fact, you should always leave a safety margin of 20%.
What I said is that when you use electrolytic capacitors on signal path, considering that the signal is about 1V RMS, you should use the lowest voltage rated capacitor you can find, preferably 10V.
Don't you put words in my mouth, as I never said what you think I said ... "
The application we are talking about is Rudis DC protection. This protection must survive the conditions it is exposed to. In this case it is supposed to protect the speaker under all circumstances including the full rail voltage over these 2 caps. You say yourself, capacitors are not to be used over their rated voltage. Yet you propose to do so in this application.
Still, what is the explanation for that I "should use the lowest voltage rated capacitor you can find" in the context of your post.
What happens if I didn't?
By Niss man - Keep up the good work Carlos and don't let a few bad egg's bring down this highly informative thread.
I don't want to be a bad egg , but here goes. When I first joined forum , I saw DX amps ,wanted to build. I have a hard time finding BC xxx parts here , have a lot of KSA/c's, Mpsa's, etc. I suggest maybe modifications to use different parts ,get shot down (told to only build it with BC's). 😡 All the DX amps work , very well ... as they are based on simple 60's RCA design. This is another issue I see while visiting the DX amp site , These amps can not be copyrighted by "DX corp." 🙄 , they are USA inventions the same as transistors and tubes and most everything else in the world!!!
I acknowledge the "DX" part can be copyrighted (maybe ) but that is it . I got reamed out for just posting a ESP audio circuit , so why does Carlos get away with posting other peoples work like this one from Doug self ? Just replace all with BCxxx's and call it your own.
The good thing is that all amps work and will not burn down the house or oscillate (I have all the sims and most DX amps are overcompensated).
ALL THIS over one input level control... 😱
OS
krachkiste,
Sorry, I thought you were talking about the input caps on the amplifier.
What I have learnt is that electrolytic capacitors work better if you use them under a voltage that is at least 10% of it's rated voltage.
So, if your voltage is 3V, you should use 35V capacitors, and not more. Again, if you're using it for audio signals of about 1V, you should use 10 or 16V capacitors, and not more.
What isn't good is using a 63V capacitor on a 1V signal circuit path.
Again, I don't recomend using a capacitor on a voltage that exceeds it's rated voltage. In fact, I always put a 20% margin of safety. Therefore, if the circuito is 40V, I will use a capacitor rated for at least 50V.
I will try to find a paper that confirms that, but I thought it was already common knowledge.
Sorry, I thought you were talking about the input caps on the amplifier.
what is the explanation for that I "should use the lowest voltage rated capacitor you can find" in the context of your post
What I have learnt is that electrolytic capacitors work better if you use them under a voltage that is at least 10% of it's rated voltage.
So, if your voltage is 3V, you should use 35V capacitors, and not more. Again, if you're using it for audio signals of about 1V, you should use 10 or 16V capacitors, and not more.
What isn't good is using a 63V capacitor on a 1V signal circuit path.
Again, I don't recomend using a capacitor on a voltage that exceeds it's rated voltage. In fact, I always put a 20% margin of safety. Therefore, if the circuito is 40V, I will use a capacitor rated for at least 50V.
I will try to find a paper that confirms that, but I thought it was already common knowledge.
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OK.
In best case, the reference you find would be able to clear the question I posed in #337
"rule": don't use electrolytics with a dc voltage below 10% of their rating
(is that what it sais?)
question: what happens if one did?
In best case, the reference you find would be able to clear the question I posed in #337
"rule": don't use electrolytics with a dc voltage below 10% of their rating
(is that what it sais?)
question: what happens if one did?
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