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DIY Stompboxes => Building your own stompbox => Topic started by: svirfnebli on December 16, 2009, 03:32:15 PM

Title: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: svirfnebli on December 16, 2009, 03:32:15 PM
Im working on a bass pre-amp replica and want to use a good quality caps. All of the originals are box caps. Wima has all the values I want which tight tolerences. Im now trying to decide between using the FKS, FKP, MKS, and MKP caps. I'm leaning towards the FKP because the tolerance is 1% which I like. I guess Im looking for some reassurance. Are there issues I should be aware of? Microphony? lifespan?

The vast majority of the caps are used in low-pass filters.

Here are what the letters stand for:

"M" = metallized construction
"F" = film/foil construction (brands of other manufacturers are missing this letter)

The second letter "K" stands for plastic film capacitors.

The third letter indicates the dielectric film used:
"S" = Polyester / PET (other manufacturers are using "T")
"M" = Mixed Dielectric
"P" = Polypropylene / PP
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: puretube on December 16, 2009, 05:27:55 PM
MKP
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: lofie on December 16, 2009, 05:48:57 PM
why MKP?
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: puretube on December 16, 2009, 05:55:39 PM
I like polypropylene...
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: svirfnebli on December 16, 2009, 07:04:59 PM
Ok so either the MKP or FKP would be good then, since both are polypropylene?
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: ElectricDruid on December 17, 2009, 03:13:06 PM
Polypropylene film caps are an excellent choice, and 1% is a very tight tolerance for caps. Only Polystyrene are regarded as better for audio, and they tend to cost an arm and a leg, or at least a couple of fingers.

T.
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: carrejans on December 17, 2009, 05:23:52 PM
I'm looking for a wima capacitor kit to buy. I saw it ones some time ago; but can't find it back.
So, no smd; and polypropylene.
Can anyone help me out?
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: carrejans on December 20, 2009, 06:37:18 AM
Quote from: carrejans on December 17, 2009, 05:23:52 PM
I'm looking for a wima capacitor kit to buy. I saw it ones some time ago; but can't find it back.
So, no smd; and polypropylene.
Can anyone help me out?

Nobody?
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: flo on December 20, 2009, 07:03:56 AM
Polypropylene capacitors in online stores close to Belgium:
FKP
http://www.newtone-online.nl/catalog/index.php?cPath=42_43_74
Xicon Polypropylene
http://www.tube-town.net/ttstore/index.php/cat/c75_Xicon-Polypropylene.html

WIMA MKS (= polyester also called mylar, not as good as polypropylene):
http://www.newtone-online.nl/catalog/index.php?cPath=42_43_66
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: carrejans on December 20, 2009, 11:12:11 AM
Thanks Flo, but I am looking for kits or packs, containing different values in one.

Something like this:
http://be02.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=1126765#header
But with polypropylene wima-style capacitors. (and bigger quantity)
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: carrejans on December 20, 2009, 11:17:02 AM
I found something more interesting at Farnell; but it's mixed types.

http://be.farnell.com/wima/wwk-101/capacitor-kit-mks2-fkp2-fks2/dp/1006066


I want something like this, with only polypropylene.
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: snk on November 13, 2017, 03:56:35 PM
Hello
I'm somewhat bringing this thread back to life.
I am going to build a RAT clone, and someone suggested me to use Wima MKT capacitors. My little concern is that i already have a bunch of Wima FKS2 capacitors : should i order some MKT, or will the FKS2 be fine ?
Will there have a noticeable difference in sound ?
Thank you in advance
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: Rob Strand on November 13, 2017, 04:32:40 PM
QuoteWill there have a noticeable difference in sound ?
I doubt anyone can really hear the difference between any of the film caps!

Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: ElectricDruid on November 13, 2017, 05:29:47 PM
Certainly not in a Rat circuit!

There might be a point in a circuit where you're trying to minimise noise and maximise performance (like for example a pole-mixing filter) but for something like the Rat distortion - no, no point.

Good quality film caps like the FKS2 are more than good enough for a Rat circuit. You won't find anything of comparable quality in an original Rat, so yours will be a "boutique" Rat!

T.
Title: Re: Which WIMA Caps to use? FKP, FKS, MKS, or MKP?
Post by: aion on November 13, 2017, 06:00:00 PM
I like FKS2 for 1n-10n and MKS2 for 10n-2.2uF.

Make sure you are aware of the size of the polypropylene (FKP2 and MKP2) before using them... good quality, but they are enormous, about the size of a 1uF film cap or even bigger.