About make an audio power amplifier.

[large_ghostman]

Turns out I have alot of different ones, but the ones I was talking about are these.

The others I dont know are these

 

[audioguru]

Some people have seen Japanese "green caps" and I also have some reddish-brown ones. I think your yellow capacitors are old Philips ones.

 

[large_ghostman]

Are either of them Audio types or just high voltage?

 

[large_ghostman]

I think they are polycarbonate

Update they are polyester decoupling timing caps apparently

**broken link removed**

 

[Nikolai Petrenko]

Thanks AG for detail about that cap.
Epcos caps in stores only available high capacitance for power supply filter, some are super cap like 5V 2,2F, no for coupling ones.

 

[Nikolai Petrenko]

You need to consider what professional audio equipment uses - and it's NOT silly priced capacitors that make imaginary claims about how they 'sound'.

Many people said like you. But it is not my thinking about caps.
I will buy 1 cap first to try. If it can make conspicous difference from cheaper cap, I will buy more. If the difference is negligible or even no, I will not throw away any small pennies.

 

[Nigel Goodwin]

Many people said like you. But it is not my thinking about caps.
I will buy 1 cap first to try. If it can make conspicous difference from cheaper cap, I will buy more. If the difference is negligible or even no, I will not throw away any small pennies.

You need to try them in double-blind tests, otherwise you simply imagine that they sound better as they cost more.

 

[spec]

No softwave, just paper, pencil and rulers.

Nikolai,
Why not use Google SketchUp or any number of other free CAD packages. Yes, the initial learning curve may be steep, but most packages are not difficult to learn, expecially SketchUp. Getting your designs into a CAD will pay big dividends in the future as you develop your designs. Instead of having to start over again, as with paper, you just build on your previous work.

 

[spec]

Just a general word about capacitors:

The absolute value of most capacitors in audio amps is not important, as most are decouplers, either low or high frequency. For these capacitors you can always go up in value, but make sure your circuits are balanced (ie negative and positive supply rails have the same value capacitance). Also, you can always parallel capacitors to make up a value, but not put them is series.

It is only frequency response shaping capacitors and Zobel network capacitors that need to be accurate to within 10%, or better as specified.

Within reason, you can also go up in value for coupling (in signal) capacitors too.

In terms of working voltage, it is best to operate solid capacitors no higher than 90% of their voltage rating, taking into account temperature. You can always fit a higher voltage solid capacitor but beware that some high voltage solid capacitors bring extra baggage that may make them less suitable for audio work.

It is best to operate aluminum electrolytics between 60% and 90% of their rated voltage, once again taking into account temperature. The reason for this tighter voltage range for aluminum electrolytics is to keep the insulating film well formed and to ensure that there is sufficient voltage to blast away weak areas and give a nice clean insulating barrier. This does not apply to tantalum electrolytic capacitors.

In terms of reservoir capacitor ripple current, the less the better, and do not exceed the maximum rating, taking special care to derate the ripple current in accordance with temperature effects which can be quite large.

Often it is not realise that aluminum electrolytic capacitors are lifed components and should be changed after the data sheet specified period has been reached- typically 5,000 hours. This is especially applicable to reservoir capacitors, have a hard life. Apart from military and special equipment though, this is rarely done. Aluminum electrolytic capacitors' are available in 85 deg C and 105 deg C rating. Roughly for every 10 deg C increase in temperature the life is halved; it is the actual electrolyte temperature that counts, not the ambient temperature.

Some cap references.
https://www.mouser.com/pdfdocs/ELNAReliabilityAlumElecCaps.pdf
https://www.cde.com/resources/catalogs/AEappGUIDE.pdf
**broken link removed**
**broken link removed**
https://en.wikipedia.org/wiki/Electrolytic_capacitor

 

[Nikolai Petrenko]

Ah, Epcos, Vishay and ERO caps also available 1uF


Most WINA are ran out.
I also search for unpolarized 22uF cap (for Rod Elliott preamp)

 

[spec]

Ah, Epcos, Vishay and ERO caps also available 1uF


Most WINA are ran out.
I also search for unpolarized 22uF cap (for Rod Elliott preamp)

Can't read the capacitor type Nicolai, but if they are what I think they are they will be good. Can you post the capacitor part number?
spec

 

[Nikolai Petrenko]

Vishay 1uF-63V
Ero 1uF - 63V
Epcos 1uF - 63V
All are polyester. Only WIMA is polypropylene but empty in store.

 

[large_ghostman]

I got some of the ones on tape not sure of the values I will try and dig them out later and have a look.

 

[audioguru]

I have some Wima 1uF/63V polyester capacitors. I looked on their website to see how much bigger the 100V one is but it looks like they do not make it anymore. Their similar-looking polypropylene capacitors are made as high as only 0.01uF with the 0.01uF/63V polyprop capacitor having exactly the same size as the 1uF/63V polyester cap.

 

[Mikebits]

I been looking for one of those polyprop assortment kits, and maybe polysty, but I have not found any. I like AG's choice of EPCOS, I have read these caps are real good.
On a side note, I came across this website the covers cap selection in great detail and may interest some readers. A lot of this info is new to me as I just recently started working in the audio range due to a project I am working on with one of my sons. (Trying to reconnect as he is 33)
Cap Selection web Link

I think a lot of this info was derived from the venerable Mr. Bateman Jedi Cap Master
I had got this article from the web, but can't remember where so here is the PDF, notes it is a fuzzy copy, but is authorized to share on the web. Oops, file is too large, sorry.

 

[Nikolai Petrenko]

Ok. I will wait until summer-when the store may received Wima from suppliers. Those Wima only slightly expensive as other brands.

 

[Mikebits]

Greetings, I found the link to the pdf file, understanding capacitors.pdf that I tried posting earlier. Hope you find it useful.
https://www.google.com/url?sa=t&rct...F13xNMgCT8G6Dw&bvm=bv.115277099,d.cGc&cad=rja

 

[spec]

Greetings, I found the link to the pdf file, understanding capacitors.pdf that I tried posting earlier. Hope you find it useful.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=13&ved=0ahUKEwiI2eWV4JDLAhVMxmMKHabgAg44ChAWCCYwAg&url=https://www.foxcomputer.se/Understanding%20Capacitors.pdf&usg=AFQjCNHMXIwjx2DfO_OLueApSrpCibaNfQ&sig2=LrPwil4kF13xNMgCT8G6Dw&bvm=bv.115277099,d.cGc&cad=rja

Nice link Mike,
I will enjoy reading that
spec

 

[tvtech]

Throwing a question here to you Guys....NAD 3020A was a beaut....I have one. Has balls and enough punch to control any speaker.

2Ohm load no problem...

Regards,
tv

 

[Mikebits]

Throwing a question here to you Guys....NAD 3020A was a beaut....I have one. Has balls and enough punch to control any speaker.

2Ohm load no problem...

Regards,
tv

So what was the question?