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2n capacitor - substitutions?

Started by lincolnic, October 28, 2010, 05:19:41 AM

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lincolnic

I'm having a lot of trouble finding a 2n cap for my Krankosaurus build, can't seem to find one on PPP, SB, or Mouser. Can I substitute 2.2n instead? How will that affect the sound? Thanks for the help.

eniacmike

2n has a cutoff frequency of 7957hz
2.2n has a cuttoff frequency of 7234 hz.

the two low pass filters in a series is a 2nd order low pass filter. a 1st order low pass attenuates at 20 db per decade, a 2nd order at 40 db per decade

these 2nd order low pass filters roll of highs very quickly above the cutoff frequency.

in a sense 2.2nF isn't going to hurt. you can also just wire up two 1n caps in a series to make a 2n cap.

there is probably some phase shift things going on too with the 2nd order low pass filter but I don't really understand how all that works enough to explain it.

http://sim.okawa-denshi.jp/en/CRlowkeisan.htm - really cool rc filter calculator that graphs your input too.

lincolnic

Thanks Mike. I think I'll wire up two 1n caps to stay true to the original design - shouldn't they be in parallel, though? I thought the rule was resistors add in series, caps add in parallel?

eniacmike

you are correct. very sorry about that.

rps-10

Sorry for raising an old thread and a nooB questiona t the same time, but is 2n the same as 2000pF ?

marmaliser


rps-10

Phew thanks, for putting my mind at rest, was overly worried about the lack of a "f" after the n  :)

Took a wild guess and ordered a 2000pf after checking this: http://www.electronics2000.co.uk/data/itemsaf/capconv.php  but I think I also found your link as well on my travels.

DutchMF

Hi,

Do you know the maths for calculating series and parallel resistors? With capacitors it's exactly the other way around, I think there is an article on Wikipedia that explains this stuff, will look it up!

Paul
"If you can't stand the heat, stay away from the soldering iron!"

DutchMF

"If you can't stand the heat, stay away from the soldering iron!"