Wiardgroup

I finally got around to writing an Excel spreadsheet to calculate all the gain settings for the 
Xpander switchable mixer.

http://www.musicsynthesizer.com/Circuitry/Multi-Function%20VCF.htm

That is what that mess of resistors does before UX14, a CD4051 eight way selector switch. 
A little later I will write a note to show how to add a simple switch between C1 and ground 
which will add in the other 8 modes for a total of 16.

I unitzed the spreadsheet data to use with the Boggie Filter and any 4 input linear mixer. 
The file is called Multimode.jpg, you will need to view it at the largest size, or download it.

The table assumes all 4 Boogie outputs are connected to all 4 inputs on a mixer with unity 
gain output and controls calibrated 0 to 100%. The table also assumes the two red option 
jumpers on the rear of the Boogie Filter are in the down position.

100% means fader is fully on, 0% means fader is fully off. 50% is fader at halfway point and  
so forth. There are a few 33% settings and a 17% setting. Feel around the suggested 
starting points for best results.

All of these are only suggested starting points. ANY setting of the mixer faders will 
produce some kind of filter. As always with music, adjust by ear and personal taste. You 
may very well discover a setting Oberheim never even knew existed. Consider running the 
24, 18, 12 and 6 dB poles through different effects chains. Unlimited sonic possibilities.

Have fun!