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DIY Stompboxes => Building your own stompbox => Topic started by: Pushtone on April 07, 2006, 02:08:10 AM

Title: Cap & resistor calculator for filters
Post by: Pushtone on April 07, 2006, 02:08:10 AM
Elliott Sound Products www.sound.westhost.com/ (http://www.sound.westhost.com/)
has an EQ project using a Multiple Feedback Bandpass Filter.
There is a freeware calculator for finding cap and resistor values for a given frequency.
Sorry Mac users, its Windows only.

It looks intriguing but the devil is in the details. Like the bi-polar PSU.
Any comments on this type of filter? Can it be integrated into 9v circuits
I guessing the calculator can only be applied to this particular filter but it would be handy if it could be applied generally.

link to his Graphic EQ project. About half way down is the link to MFB Filter design program.exe
http://sound.westhost.com/project64.htm (http://sound.westhost.com/project64.htm)

It needs a dll to run. The link for the dll is provided if you don't already have it on your system.
Download, unzip, and drop the dll into /Windows/system/ folder

Here is the link to the multiple-feedback bandpass filter page
http://sound.westhost.com/project63.htm (http://sound.westhost.com/project63.htm)

And finally heres a screen cap of the program.
http://www3.telus.net/david65/ESP-FilterCalculator.GIF (http://www3.telus.net/david65/ESP-FilterCalculator.GIF)

The description of the EQ projects sound interesting enough to build too;
Quote"This equalizer is designed as a preamp suitable for musical instruments - guitar, bass and keyboard in particular. Unlike most conventional graphic equalizers, each slider ranges from fully off to fully on, and not the more conventional +/-12dB or so that is normally available. As a result, there is no flat setting (other than all off!). This graphic is designed to be used to create a sound, and is not suitable for hi-fi. It may be used as an add-on unit to existing instrument amp preamps, tone controls, etc. The flexibility is extraordinary, allowing a hollow "single frequency" type sound, right through to almost any tonal variant imaginable."
Title: Re: Cap & resistor calculator for filters
Post by: rockgardenlove on April 07, 2006, 03:27:44 AM
These things are never for Mac  >:( >:( >:(

(Yes, its so bad, it deseves 3 angry faces  8) )
Title: Re: Cap & resistor calculator for filters
Post by: Sam on April 07, 2006, 10:39:41 AM
Quote from: rockgardenlove on April 07, 2006, 03:27:44 AM
These things are never for Mac  >:( >:( >:(

(Yes, its so bad, it deseves 3 angry faces  8) )

I've noted that too. It deserves at least four angry faces.
Title: Re: Cap & resistor calculator for filters
Post by: rockgardenlove on April 07, 2006, 08:07:35 PM
Agreed.  Here's the 4th.

>:(
Title: Re: Cap & resistor calculator for filters
Post by: Noplasticrobots on April 08, 2006, 02:04:40 PM
Here's my fifth!  >:(

I just use this calculator: http://www.opamplabs.com/rfc.htm
Title: Re: Cap & resistor calculator for filters
Post by: Peter Snowberg on April 08, 2006, 07:43:09 PM
Silly rabbits, everything runs on the Mac.  :icon_wink:

http://darwine.opendarwin.org/index.php
http://www.apple.com/macosx/bootcamp/
http://www.microsoft.com/mac/products/virtualpc/virtualpc.aspx?pid=virtualpc
http://www.lismoresystems.com/en/
Title: Re: Cap & resistor calculator for filters
Post by: mac on April 09, 2006, 10:44:38 PM
Quote from: Peter Snowberg on April 08, 2006, 07:43:09 PM
Silly rabbits, everything runs on the Mac.  :icon_wink:

http://darwine.opendarwin.org/index.php
http://www.apple.com/macosx/bootcamp/
http://www.microsoft.com/mac/products/virtualpc/virtualpc.aspx?pid=virtualpc
http://www.lismoresystems.com/en/

yeap, but anyway here is the 6th >:(

mac
Title: Re: Cap & resistor calculator for filters
Post by: Noplasticrobots on April 28, 2006, 02:46:03 PM
Everything runs on Mac if you've paid, oh about 500 bucks in the last few years for upgrading! The only downside to Apple...