AM3372 Module - Oberheim Matrix 12 Filter

Overview This module is designed around the CEM3372 VCF chip which featured in the Oberheim Matrix 12 and Expander synthesizers in the mid 1980's. The filter can be configured in 15 different ways; providing a nice variety of Low, Band and High Pass filters at various poles.

The idea of basing a module around the CEM3372 Matrix 12 VCF implementation is not new. Jesper Erwik Johansson in Sweden developed such a module in 1998, and sold a limited edition of 12. Jesper added some interesting features, such as a front panel display of filter type and the ability to clock through the filter modes. He also made use of the three VCA's on the input side of the filter core.

Doepfer also have a version of this filter, using Jespers ideas and then some more. They have added the ability to morp between filter modes, and added another 16 filter types. This is a micro-controller based implementation but only a 7-segment LED display.

AM Module Overview The AM3372 is based on the Matrix 12 implementation of the filter chip with 15 filter modes, which can be sequentially clocked externally up or down. A minature 16x2 blue display shows the filter type in text, just like the original Oberheims.

AnalogDNA Technology

This module uses AnalogDNA technology.
A PIC Microcontroller chip reads the front panel rotary encoder and incoming clock pulses, as well as displaying filter types on the LCD.
A more advanced implementation could read a complete set of front panel controls and store them as patches.
 

Product Sales

This design is in development and may be available in 2007. The PIC software has been developed and a prototype filter board is being tested.
 

Sound Clip

* ERWIK FILTER Jesper doesn't seem to have a web site, but there are some details of his Matrix 12 filter at this link. more »

* DOEPFER MODULE The A107 Module details are on their web site. more »