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Projects => Tech Help - Projects Page => Topic started by: danwelsh on March 06, 2013, 10:23:00 PM

Title: help to substitute cap values....?
Post by: danwelsh on March 06, 2013, 10:23:00 PM
Hi guys, just wondering if its possible to substitute certain cap values, I ordered my build parts and screwed up when i ordered 2 values.....I'm looking at building the thunderpuss, and zero point micro and the cap values  i need to substitute are the zero point micro- c1 calls for a 220pf(ceramic)...can i use a higher value for this? And the thunderpuss c2 calls for a 47pf....can i sub a higher value for that also?  Thanks in advance for anyone who can help me
Title: Re: Re: help to substitute cap values....?
Post by: stevie1556 on March 06, 2013, 10:33:09 PM
Ideally, you want the correct values, or very close values. If you connect 2 capacitors in parallel then the total capacitance will be C1 + C2. Depending on what capacitors you have to hand, you maybe able to get a closer value by doing that rather than using a higher value cap.

I've never built either of these pedals before so I can't really comment further though as I don't know how different values will affect the pedals.

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Title: Re: help to substitute cap values....?
Post by: danwelsh on March 06, 2013, 10:34:43 PM
can i use ceramic discs....i can get close to the correct values if i buy an assortment from radio shack...they have a 68pf/50v and 221pf/50v....these?
http://www.thesource.ca/estore/product.aspx?language=en-CA&product=2720801&category=Resistors&catalog=Online&tab=2#more
Title: Re: Re: help to substitute cap values....?
Post by: jimilee on March 06, 2013, 11:34:04 PM
Anything that will get you there, as long as it does not call for electros
Title: Re: Re: help to substitute cap values....?
Post by: danwelsh on March 06, 2013, 11:38:47 PM
Quote from: jimilee on March 06, 2013, 11:34:04 PM
Anything that will get you there, as long as it does not call for electros

okay thanks jimilee....it calls for ceramic, sucks that i gotta pay 7.99 plus tax to get 2 caps...
Title: Re: help to substitute cap values....?
Post by: mgwhit on March 07, 2013, 12:08:32 AM
Picofarad value caps are almost always going to be ceramic disks.  A 221pF cap will be indistinguishable from a 220pF.  The 68pF should be fine in the Thunderpuss.  Remember, we're usually using parts that have 5-20% tolerances.
Title: Re: help to substitute cap values....?
Post by: danwelsh on March 07, 2013, 01:15:04 AM
okay thanks guys
Title: Re: Re: help to substitute cap values....?
Post by: jimilee on March 07, 2013, 02:02:23 AM
Quote from: danwelsh on March 06, 2013, 11:38:47 PM
Quote from: jimilee on March 06, 2013, 11:34:04 PM
Anything that will get you there, as long as it does not call for electros

okay thanks jimilee....it calls for ceramic, sucks that i gotta pay 7.99 plus tax to get 2 caps...
Why don't you just get them from Tayda? way cheaper shipping
Title: Re: help to substitute cap values....?
Post by: danwelsh on March 07, 2013, 02:22:42 AM
Its not 7.99 for shipping... thats what the assorted caps cost at our radio shack(the source)....way overpriced but the way im lookin at it is i'll have em tomorrow and i'll likely be needing the rest of the values eventually for more builds.  ...plus i need to get solder anyways at the same store
Title: Re: help to substitute cap values....?
Post by: jimilee on March 07, 2013, 04:16:54 AM
oohhhh well that's cool. I use them from time to time myself. Good to support local businesses,not always economical. Good on you