How to choose wima capacitors? - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st April 2011, 03:37 PM   #1
dboris is offline dboris  France
diyAudio Member
 
Join Date: Mar 2011
Default How to choose wima capacitors?

Hello!

I'm trying to do a Echo Base (delay guitar pedal), but with good quality components.
I have read threads, and wima capacitor seems to be the best value for price.

There is a lot of capacitor type, and i have found theses posts:


Quote:
FKP2 is said to be the best choice but is only available in small values. MKP4 is a really good budget audio cap and is available in larger values.

MKP10 is supposed to be good as well, but I have not tried them, so cannot recommend them.

MK2/MKP2/MKP4 are good sounding caps for decoupling, IMHO.

MKP4/MKP10 are not bad for coupling but film/foil types like Audyn Cap KP Sn or Mundorf MCAP Zn are MUCH better (both for transprency and tonal balance).

Get MKP, not MKS.
And take a look at the bom:

http://s3.noelshack.com/uploads/imag...0352019__2.png

Wima FKP2 have a range of 100pF to 0.033uF.
WIMA

So i can only use 4 FKP2!

In my shoping card, all other capacitors are MSK2... And it have been said that they are not good for audio!

So what should i buy?

And i have another project with 20x 100nF capacitors...
I have searched, but haven't found which one buy in this case!


Thanks a lot!

Boris.
  Reply With Quote
Old 5th April 2011, 02:30 AM   #2
rsdio is offline rsdio  United States
diyAudio Member
 
Join Date: Feb 2008
Location: Seattle
One consideration is the corner frequency of the high pass filter that is created when you place a series capacitor in front of the impedance of your input stage.

I don't see a handy link to a schematic for this project, but it sure would take less time than trying to reverse-engineer the schematic from the PCB layout. The schematic would show you the input stage and allow you to calculate the input impedance from the chip specifications and gain resistors. Once you know the input impedance, you should be able to calculate an appropriate capacitance for your WIMA parts based on the frequency response that you desire. e.g., you might want to extend below 20 Hz for subsonic effect, or you might want to high pass above 20 Hz if your guitar does not need those really low frequencies.
  Reply With Quote
Old 6th April 2011, 03:00 PM   #3
diyAudio Member
 
Join Date: Mar 2011
Make sure that you buy from a reputable site. There are a lot of counterfeit WIMA's out there.
  Reply With Quote
Old 16th May 2011, 11:05 PM   #4
dallek1 is offline dallek1  United States
diyAudio Member
 
Join Date: Nov 2010
Default how do i tell bad caps help

Quote:
Originally Posted by apw100 View Post
Make sure that you buy from a reputable site. There are a lot of counterfeit WIMA's out there.
do these look real


from viodol

WIMA Polyester Capacitors MKS4 0.022uF 400V 10% - 3PCS | eBay
Attached Images
File Type: jpg 0.022_400v.jpg (16.0 KB, 1435 views)
  Reply With Quote
Old 17th May 2011, 04:54 AM   #5
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
i would take vishay box caps over wima anyday, wima has the bonus of being red, which is why i think they are so popular. other nice small value film and foils (not just metalized films) are the amtrans polypropylene, evox/rifa film and foil and relcap. do not buy wima from ebay full stop; that is 100% fake in that pic. even the legit one would be polyester crap. go for polypropylene whenever size and cost allows
  Reply With Quote
Old 17th May 2011, 05:09 AM   #6
diyAudio Member
 
digits's Avatar
 
Join Date: Apr 2011
You do get wima popyprop too...
I do like vishays though.
  Reply With Quote
Old 17th May 2011, 06:41 AM   #7
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
yeah i know that, but most are not film and foils, they are generally metalized film and any of their film and foils in any useful value are massive and meant for much higher voltage than what they are generally used for. i just find all this fuss about wima to the point of their being numerous fakes, to be a bit funny, as they are at best equivalent to numerous other similar parts and in some cases inferior. panasonic make excellent pp film caps also.
  Reply With Quote
Old 17th May 2011, 06:43 AM   #8
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
i like blue better also if the op can find them in the right value, you really cant go past the vishay/sprague orange drop

i recomend checking out audiocap.net they have a good range all in one place, as well as some higher end ones (not crazy high) like auricap, which is another favorite of mine. here is the evox/rifa film and foil small box cap, only in small values up to 4.7nf at that place and they are not easy to find elsewhere.

they have legit fkp 2/3 from wima if you vust and at a decent price. personally for filters i would be looking at polystyrene if the placement isnt going to be subjected to high temp. its a great site and they have a massive range of high end power supply electrolytics too, like the evox/rifa phe169, which others as well as myself see as the best power supply cap on the planet

Last edited by qusp; 17th May 2011 at 06:55 AM.
  Reply With Quote
Old 17th May 2011, 09:39 AM   #9
rsdio is offline rsdio  United States
diyAudio Member
 
Join Date: Feb 2008
Location: Seattle
EVOX RIFA (KEMET) come in blue, too.

I use Mouser as a distributor, and they seem to have fair prices for both EVOX and WIMA.
  Reply With Quote
Old 17th May 2011, 10:24 AM   #10
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Blog Entries: 22
It's a bit hard to tell without a schematic! A capacitor should be chosen based on what it's intended use is. The datasheet should be able to help with this. At the most basic level if it is a coupling cap then look for coupling cap in the applications of the datasheet for instance you might look at two polypropylene caps, one might say it is good for coupling, the other may be an X2 interference suppression cap Which one would you choose?

without really knowing what the application is, I'll throw the good old vishay MKP1837's into the ring, they would cover most of the values you have on that bom, and their tolerances are excellent.

The other thing you should consider is that some of the caps may be supply decoupling caps for the IC's and depending on the particular IC's some NPO ceramics may actually be the best choice for that duty.

For the values available I do like the FKP2's, though if you are thinking of substituting them for ceramics make sure it is actually the right thing to do (ie ceramics were specced for cost rather than because of the specific advantages they have with high frequencies).

Tony.
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Capacitors for audio WIMA FKP2 WIMA Swap Meet 1 20th October 2009 10:21 AM
Capacitors for audio WIMA FKP2 WIMA Vendor's Bazaar 0 27th September 2009 08:16 PM
WIMA FKP2 Capacitors zxcxz Swap Meet 0 4th March 2009 02:11 PM
Rifa & Wima polypropylene capacitors xecluded Swap Meet 8 1st September 2008 01:46 AM
For sale: 1.5uf 63v WIMA MKP capacitors. Spasticteapot Swap Meet 2 23rd November 2006 11:30 PM


New To Site? Need Help?

All times are GMT. The time now is 03:08 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2