In the real world of today (apart some class D amps) everybody is using symmetrical designs. No need of caps in the signal path. (May-be one in the input line of the power amp ?)
For protection of the loudspeaker, it is a bad solution. You need to use large caps if you need to play low frequencies with no phase effect. If you burn (in short cicuit) one of your push-pull output transitor, the hp output will goes on the + or - rail. The big cap will be charged with a big current across your loudspeaker.
The loudspeker will not like-it. Or it will burn, or the moving coil will hit the back plate of the magnet (do not know the world in English) and the voice coil will be rubbing in the gap (again, my English !): No more boomer.
I use a relay to protect my amplifier from sending any bad or dangerous signals to the speakers.
Just comparing input and output signals, and cutting a relay on the output if too much a difference. ( Amplifier has to be a strait line with gain).
It protect very efficiently from power-on/off "clocs", Hf oscillations, clipping, DC current in the output. It is faster than sensing the DC across any integrating filter solution and simple to design . Protection will react fast as light.
If any is interested, i can publish my shematic on my web site. Needs a cheap quad op-amp, two transistors to drive the relay, and very few components around. It include a delay on power on and cut output on power off.
For protection of the loudspeaker, it is a bad solution. You need to use large caps if you need to play low frequencies with no phase effect. If you burn (in short cicuit) one of your push-pull output transitor, the hp output will goes on the + or - rail. The big cap will be charged with a big current across your loudspeaker.
The loudspeker will not like-it. Or it will burn, or the moving coil will hit the back plate of the magnet (do not know the world in English) and the voice coil will be rubbing in the gap (again, my English !): No more boomer.
I use a relay to protect my amplifier from sending any bad or dangerous signals to the speakers.
Just comparing input and output signals, and cutting a relay on the output if too much a difference. ( Amplifier has to be a strait line with gain).
It protect very efficiently from power-on/off "clocs", Hf oscillations, clipping, DC current in the output. It is faster than sensing the DC across any integrating filter solution and simple to design . Protection will react fast as light.
If any is interested, i can publish my shematic on my web site. Needs a cheap quad op-amp, two transistors to drive the relay, and very few components around. It include a delay on power on and cut output on power off.
Last edited:
I agree with all except follow:
Have a look about the PDF-Files by post #2 about
http://www.diyaudio.com/forums/soli...ter-reference-amplifier-schematic-wanted.html
This company makes custom made MKP caps up to 20.000 uF.
If space and money dosn't matter, the ultimative choice for power amplifier power supplies.
now the home page from this special company also in english available:
http://www.electronicon.com/en/prod...lectronics/capacitors-with-large-capacitance/
Have a look about the PDF-Files by post #2 about
http://www.diyaudio.com/forums/soli...ter-reference-amplifier-schematic-wanted.html
This company makes custom made MKP caps up to 20.000 uF.
If space and money dosn't matter, the ultimative choice for power amplifier power supplies.
now the home page from this special company also in english available:
http://www.electronicon.com/en/prod...lectronics/capacitors-with-large-capacitance/
Last edited:
Sadly I fall in the group that hears difirences between capacitors, which tend not to be price related, thank g_d. And by that I don't mean I could generaly tell from changes in every amp and every position. Just sometimes in some positions in some amps, the changes are to me as clear as diffirent flavours of chips.
I have to say that I also have a preferance for higher voltage caps.
Higher voltage caps tend to almost as a rule have lower ESR, but as they physicaly get larger they also have higher inductance. When useing a good quality cap on a rail, I am though seldeomly able to hear any addition of film caps.
However in passing signal, I realy do not like useing electrolytics on their own (or at all if there is a choice). Antiparallel is a step up, but best (value for money) is any polyprop bypass then.
Sadly most of my experience is annecdotal, and the multiple of annecdote is apparently not data.
I have to say that I also have a preferance for higher voltage caps.
Higher voltage caps tend to almost as a rule have lower ESR, but as they physicaly get larger they also have higher inductance. When useing a good quality cap on a rail, I am though seldeomly able to hear any addition of film caps.
However in passing signal, I realy do not like useing electrolytics on their own (or at all if there is a choice). Antiparallel is a step up, but best (value for money) is any polyprop bypass then.
Sadly most of my experience is annecdotal, and the multiple of annecdote is apparently not data.
I understand that some don't like the additional resistance a relay can add, reducing damping factor. So you have to chose a over-sized very good one for this purpose.
reliability is not an issue. ( my amp is more than 10 years old). Faillure will be on the contact side, relay is off by default, so unless the contacts sold themselves...
I do not want to read all that stuff Dudainc.... as you are a very close friend
please, tell me the conclusion.... does it sound or not? ....say... the one wrote the paper said it sounds?
"Me dá um resumo...Haja paciencia para ler essa coisa imensa impresso com letras pequeninas e com côres exdrúxulas."
translation:
"Give me a summary ... can not find the patience to read this huge thing with tiny letters printed with strange colors... the lack of contrast does not help an old man vision."
It's a little hard for me to focus and spend time reading a treatise of this size, to know what this guy thinks ... and understand the techniques he used to set the test .. finally .. a complication of hell to check something that, quickly and easily, we discover when we replace a dozen capacitors in the input of an amplifier.... after a couple of minutes we conclud that they all offer absolutely the same result.
Yesterday i did that.... was a dozen.... no difference...and i did it for one hour long.... if there's a difference, only instruments will detect..human ear does not detect.... or my personal ear cannot detect.... if human ear cannot detect..then they do not sound different.
It would be easier to uncle charlie to believe that someone i found inside a Psychiatric hospital, an an internee, that goes stating and telling me he is Napoleon Bonaparte, than to believe a capacitor sounds.
regards,
Carlos
please, tell me the conclusion.... does it sound or not? ....say... the one wrote the paper said it sounds?
"Me dá um resumo...Haja paciencia para ler essa coisa imensa impresso com letras pequeninas e com côres exdrúxulas."
translation:
"Give me a summary ... can not find the patience to read this huge thing with tiny letters printed with strange colors... the lack of contrast does not help an old man vision."
It's a little hard for me to focus and spend time reading a treatise of this size, to know what this guy thinks ... and understand the techniques he used to set the test .. finally .. a complication of hell to check something that, quickly and easily, we discover when we replace a dozen capacitors in the input of an amplifier.... after a couple of minutes we conclud that they all offer absolutely the same result.
Yesterday i did that.... was a dozen.... no difference...and i did it for one hour long.... if there's a difference, only instruments will detect..human ear does not detect.... or my personal ear cannot detect.... if human ear cannot detect..then they do not sound different.
It would be easier to uncle charlie to believe that someone i found inside a Psychiatric hospital, an an internee, that goes stating and telling me he is Napoleon Bonaparte, than to believe a capacitor sounds.
regards,
Carlos
Last edited:
read this informations carefully:
Capacitor plague - Wikipedia, the free encyclopedia (engl.)
Capacitor Plague ? Wikipedia (German)
Capacitor plague - Wikipedia, the free encyclopedia (engl.)
Capacitor Plague ? Wikipedia (German)
Tiefbass thanks for the atached link to this two interesting article !
BTW , my experiences with Elkos from this PC units is that this elkos & PC unit failure was mainly directly depend from quality of few small value elkos placed on the primary side of SMPS PC power supply unit .
Way of Failure mechanic is usually next :
When this few small elkos lose the nominal capacitance SMPS PSU start to goes wild , raising often secondary side DC voltage significantly and schifting primary & secondary nominal designed working frequency significantly up.
PSU secondary side elkos than start to suffer from abnormal voltage & frequency shift and start to deteoriate prematurely , in one moment the whole PC unit will fail .
Same things usually happen in other SMPS powered electronic units , TV`s , monitors , ....etc.
Regularly even today when I by some `no name` brand new PC PSU box I change this few small elkos with high quality fresh ones , that`s small modification extend both PSU & PC unit life significantly ! ,
For example when I start to repair some broken TV or...., first thing I made is to replace SMPS PSU primary side few small elkos with fresh ones and only than I proceed with repairing unit in other failed regions .
Best Regards !
Best Regards !
BTW , my experiences with Elkos from this PC units is that this elkos & PC unit failure was mainly directly depend from quality of few small value elkos placed on the primary side of SMPS PC power supply unit .
Way of Failure mechanic is usually next :
When this few small elkos lose the nominal capacitance SMPS PSU start to goes wild , raising often secondary side DC voltage significantly and schifting primary & secondary nominal designed working frequency significantly up.
PSU secondary side elkos than start to suffer from abnormal voltage & frequency shift and start to deteoriate prematurely , in one moment the whole PC unit will fail .
Same things usually happen in other SMPS powered electronic units , TV`s , monitors , ....etc.
Regularly even today when I by some `no name` brand new PC PSU box I change this few small elkos with high quality fresh ones , that`s small modification extend both PSU & PC unit life significantly ! ,
For example when I start to repair some broken TV or...., first thing I made is to replace SMPS PSU primary side few small elkos with fresh ones and only than I proceed with repairing unit in other failed regions .
Best Regards !
Best Regards !
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.