AM 8002 Module - Audio Mixer and Ring Modulator

Overview  This module takes the Ring Modulator and Audio Mixer from the Roland SH-5 and puts them into a separate module, which sits in front or either the Roland SH-5 filters (AM8005) or SH-3 Filters (AM8003). Roland used a similar audio mixer in all their analog desktop mono synths from the 1970's.

The AM8002 has three audio signals which are switched into either of the 2x filter banks, along with output of Ring Modulating the first two signals. The filter signals are all mixed together, and slide switches have a centre off position so the audio signal can be muted.

AM8002 Module The original passive Roland design has been reworked into an active design with modern Op Amps. The initial batch of PCB's use Jupiter 6 pots and control knobs. The Ring Modulator is based on the MC1496 chip, just like the original circuit found in the SH-5 and Roland 100M.

There are two PCB's

• Pot PCB: 4 sliders and 4 switches
• RM PCB: Ring Modulator and post VCF audio mixer

The module has the following front panel controls:

• Signal Input Levels (x4) - one is prewired to Ring Modulator
• Four 3-way switches to route these signals to Diode, Moog or both VCF's

There are five 3.5 mm jack sockets mounted at the base of the panel, these are:

• Signal Inputs (x3)
• Modulation Control Inputs (x2)

Front Panel The front panel has 4x slide pots and 4x three way slide switches. The pots control the level from 3 audio sources plus the ring modulation from a mix of Signal A and B. The slide switches route the signals to either or both of the filters.
 

Roland SH-5 Mixer