AM8111 VCO & VCF

AM8111 is a re-imagined replica of the Roland 100M 111 module, a prototype that Roland made in 1978.

OVERVIEW:
The AM8111 is a replica of the Roland 100M 111 module, a prototype that Roland made in 1978 but without taking it into production. It is a combination of a VCO and a VCF in the same module. The original 111 has been re-imagined by using the oscillator from the SH-101 and the filter from the Korg Monopoly. New sounds!

DESCRIPTION:
The VCO is based on the Coolaudio V3340 chip with additional trimmers to enable easy setup, and precision voltage rails to ensure pitch stability. The VCO has three waveforms; Triangle, Pulse, Sawtooth along with a sub ocillator one octave below. The VCO has sync with two strengths (weak, strong) selected by a slide switch. The main outputs of the VCO are normalised into the signal inputs of the VCF.

The Korg Monopoly style VCF is based on the Coolaudio V2044 chip, with a slide switch to select whether the envelope input is inverted or not. Q compensation has been implemented to ensure there is no signal level drop at higher resonance settings. The filter is trimmed to go into self oscillation at the maximum resonance setting.

There are trimmer pots for the audio and CV inputs, slide pots for frequency cutoff and resonance, and a rotary controls for VCO range and pitch. The module is designed to work with audio signals up to 10V p-t-p and CV signals from 0 - 10V. There are green and red LED's on the VCF, which represent signal active and signal overload.

CONNECTIONS:
There are 16x 3.5 mm jack sockets on the front panel:

• 3x VCO CV inputs
• 1x Pulse Width input
• 1x VCO output
• 1x SUB output
• VCO sync input & output
• 3x VCF audio inputs
• 3x VCF frequency cutoff CVinputs
• 2x VCF outputs

The module comes with a set of M3 mounting screws and washers, and a standard Eurorack 10-pin to 16-pin power cable.