They work but they are intended for mains use ( these are only ones that don't blow on 230 V AC ). I once used 1 uF X caps from Rifa for audio with good results but I avoid them in general. Please do a small study yourself on what makes a cap a X or Y version at a manufacturers site for correct understanding.
Standard MKP or the pulse variants FKP are good in audio so that's what I use.
Standard MKP or the pulse variants FKP are good in audio so that's what I use.
Don't forget PPS
Polyphenylsulphide is an increasing available dielectric, that sounds excellent.
Technically it's up there with polystyrene and polypropylene, with the added advantage that you can get quite large values in sensible package sizes quite readily. I've used Panasonic and Evox Rifa, in SMD and leaded format.
Andy.
Polyphenylsulphide is an increasing available dielectric, that sounds excellent.
Technically it's up there with polystyrene and polypropylene, with the added advantage that you can get quite large values in sensible package sizes quite readily. I've used Panasonic and Evox Rifa, in SMD and leaded format.
Andy.
Well I looked thru all of farnells Polyphenylsulphide caps and all they had was SMD, this isnt really a problem for my next project, but as an upgrade to my current Active xover I cant really add SMD. The polyprop caps that farnell had that I liked the look of were these, are these suitable, as I would be after 3.3 and 4.7 nano versions to replace the trebble and mid legs in my active xover.
http://uk.farnell.com/jsp/catalog/v...=017011&categories=UK0-AC~017000000~017011000
What a URL
"edit" look at that DIY shrinks the URL 
I wouldnt bother with the bass section for obvious reasons all it produces is thump which is does well enough as it is.
http://uk.farnell.com/jsp/catalog/v...=017011&categories=UK0-AC~017000000~017011000
What a URL
"edit" look at that DIY shrinks the URL I wouldnt bother with the bass section for obvious reasons all it produces is thump which is does well enough as it is.
shoog
Anyone know the quality of MPE as these are what I am using as my DC blocking caps in my preamp. I am using old fashioned round Wima golden clear caps in my Power amp, but there is no indication of dielectric. Any ideas on both types.
Shoog
Anyone know the quality of MPE as these are what I am using as my DC blocking caps in my preamp. I am using old fashioned round Wima golden clear caps in my Power amp, but there is no indication of dielectric. Any ideas on both types.
Shoog
Cheers for that I found them now, there nice and cheap to in comparison to what people say they are paying for MKP wimas. If they sound excellent then I think I will order a few, next time I need something from farnell, minimum £10 order etc. pity they are not on 7.5mm pitch as thats what my PCB is now 🙁 I can cope mind you 😀
I don't want to contradict what has been said before but :
It is true the better the capacitor the bulkier it is,
generally, and consequentially the more it costs.
And the accepted ranking is : (though PC/PP is argueable)
(ignoring metalised / foil differences)
Mylar / PolyEster
PolyCarbonate
PolyPropylene
PolyStyrene
hideously expensive
I would have thought effective pairing of the different types
to cover a wide range of required values is more sensible
than advocating a particular type.
For example :
PS is the best.
Next is PP with PS in parallel.
Next is PP.
Next is PC with PC in parallel.
Next is PC.
Next is PE with PC in parallel.
Next is PE.
But the obvious question is PC||PS better than PP,
and what ratio's of values are needed ?
Or do you need to parallel all four types ? (for high values)
I've no idea. Though I'm sure parallel combinations
are more cost effective and I use combinations that
appear to be ~ sensible to me.
🙂 sreten.
It is true the better the capacitor the bulkier it is,
generally, and consequentially the more it costs.
And the accepted ranking is : (though PC/PP is argueable)
(ignoring metalised / foil differences)
Mylar / PolyEster
PolyCarbonate
PolyPropylene
PolyStyrene
hideously expensive
I would have thought effective pairing of the different types
to cover a wide range of required values is more sensible
than advocating a particular type.
For example :
PS is the best.
Next is PP with PS in parallel.
Next is PP.
Next is PC with PC in parallel.
Next is PC.
Next is PE with PC in parallel.
Next is PE.
But the obvious question is PC||PS better than PP,
and what ratio's of values are needed ?
Or do you need to parallel all four types ? (for high values)
I've no idea. Though I'm sure parallel combinations
are more cost effective and I use combinations that
appear to be ~ sensible to me.
🙂 sreten.
For the ultimate tweakoid, you can make PPS highly conductive using strong oxidants as dopants- the classic is arsenic pentafluoride mixed with arsenic trifluoride. Applied to both sides of an undoped PPS film, you've got a capacitor using no metal whatsoever. Very cool.
Don't try this at home!
Don't try this at home!
Well the PolyStyrene caps at farnell are not hideously expensive if they are the best that money can buy save for "hideously expensive". These would be easier to use then the other caps as they are axial so pitch on a PCB is of less importance. They are 1% jobbies too so are very accurate.
http://uk.farnell.com/jsp/catalog/v...U3PMZHMLAPHQFIAEXCFE4AVAAS2IV3?prodId=3039651
im guessing they would be a good choice, appart from the expense, which although isnt huge is still more then the others!
http://uk.farnell.com/jsp/catalog/v...U3PMZHMLAPHQFIAEXCFE4AVAAS2IV3?prodId=3039651
im guessing they would be a good choice, appart from the expense, which although isnt huge is still more then the others!
sreten said:
It's easy, don't parallel caps but use just one good type. BTW your words are not contradictive IMO. The bigger the better ( when you have 5 mm pitch you'll talk different 😉 ).
I used to parallel caps too but I discovered that using a plain good cap wins from a paralleled combo. Certainly paralleling Black Gate caps with MKT/MKP etc. does not give optimal results to say the least.
JP - I've no doubt a plain cap is better than a combo.
But its a lot more expensive. Unless you are saying
that a plain cap is obviously so superior to a combo
that using combos is essentially pointless.
Or in other words combos don't work well at all.
🙂 sreten.
But its a lot more expensive. Unless you are saying
that a plain cap is obviously so superior to a combo
that using combos is essentially pointless.
Or in other words combos don't work well at all.
🙂 sreten.
OK well a slightly different question but still caps!
How siginificant is the capacitor in the feedback of an opamp active filter to the overall sound quality. This is in comaprison to the cap that would be directly in the signal path.
How siginificant is the capacitor in the feedback of an opamp active filter to the overall sound quality. This is in comaprison to the cap that would be directly in the signal path.
5th element said:
The two are directly equivalent as far as I know.
The only differences AFAIK is when an electrolytic DC coupling
capacitor is included inside an AC coupled feedback loop and its
alleged degradation* is reduced by the feedback factor.
🙂 sreten.
* All too real for capacitors in certain coupling circumstances.
OK well I think I will shell out on some new polystyrene caps and see what happens!
What are the overall gains from upgrading, im hesitant to spend quite a bit on caps as the sound I get does not have any negative attributes to it.
Its smooth as hell, no trebble grain, lots of detail, very open, very dynamic etc.
What are the overall gains from upgrading, im hesitant to spend quite a bit on caps as the sound I get does not have any negative attributes to it.
Its smooth as hell, no trebble grain, lots of detail, very open, very dynamic etc.
The main caution with polystyrenes is to keep them WELL away from any heat. They'll fail at temperatures where PET, PC, PP, and PPS aren't even breaking a sweat.
Ok well I think I can easily use the Polystyrenes, the inside temperatures are room temperature, well maybe a coupla degrees higher but no higher.
Caps in feedback of opamp - stability
I must agree with sreten. However, since a "stability" cap is working well above one decade over 20 khz one might be able to shave the budget here.
I have made room for pp caps here in my active xover, but plan to test it with different types to see what difference it makes.
\Jens
5th element said:
sreten said:
I must agree with sreten. However, since a "stability" cap is working well above one decade over 20 khz one might be able to shave the budget here.
I have made room for pp caps here in my active xover, but plan to test it with different types to see what difference it makes.
\Jens
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