[sdiy] doepfer a107 cem3372 oberheim expander filter

[Niels A. Moseley]

Hi,  Stefan..

> You can use the same trick with pretty much any 4pole filter that 
> provides single output per stage (ladder filters are out, OTA & 
> SSM2040 should work).
>
> The idea is to sum the individual taps with different weights. The 
> XPander service manual provides the needed equations to calculate the 
> weighs (you do have to do some math though).

http://matrix-12.tripod.com/service.htm

You want page 26 and 27

Enjoy!

Regards,
Niels.

ps. ik zit in Enschede.. en jij?