AM8325 OBIE-XA VCF

Recreation of the 2 & 4 pole filters in the Oberheim OB-Xa

The AM8325 module is a recreation of the 2 and 4 pole filters in the Oberheim OB-Xa. The filter uses two AS3320 filter chips to produce an amazing sounding VCF. The 2-pole filter is a state variable, reminiscent of the Oberheim SEM, with low pass and high pass outputs. The 4-pole filter is a classic 24dB OTA low pass.

The filter has two audio signals inputs with level control (OSC1, OSC2), frequency cutoff and resonance controls, along with two frequency modulation controls (MOD and ENV). There is also a dedicated keyboard input for controlling the filter cutoff from a pitch signal.

Front panels slide switches control whether the keyboard pitch CV is ON or OFF, and which filter mode is provided at the output:

2-pole low pass
2-pole high pass
4-pole low pass

There are six 3.5mm jack sockets mounted on the bottom of the panel;

Signal Inputs (x2)
CV Inputs (x2)
Keyboard Input
Signal Output.

https://www.amsynthstore.co.uk/AM8325_OBIE-XA_Filters/p1461448_21395532.aspx