Complete miniature synthesizer voice module

VCO

• triangle core VCO
• manual tune control and octave switch
• modulation input for frequency (FM) or pulsewidth modulation (PM)
• manual pulsewidth control
• waveform switch (sawtooth / off / triangle)
• 1V/oct input
• Balance unit : two inverse working VCAs controlled by manual control and CV input, VCA1 is connected to the VCO output, VCA2 to the socket Ext.In. which is normalled to the internal sub-octave signal (f/2)

VCF

• 24 dB low pass, 10Hz ... 20kHz
• manual frequency control
• two frequency modulation inputs, FM1 (with attenuator) is normalled to the internal Envelope signal, FM2 without attenuator (about 1V/oct, e.g. for VCF tracking or sine wave VCO)
• manual resonance (up to self oscillation = sine wave VCO)

VCA

• initial gain (to open the VCA without envelope)
• controlled by internal envelope or gate signal

Envelope

• AR/ADSR/AD mode selectable via switch
• manual controls for Attack and Decay/Release
• Sustain is fixed to 50% in ADSR mode and D=R
• CV input for time control, by means of two internal jumpers one can select which time parameters are controlled by the CVT input (e.g. A only or D/R only or A/D/R) and in which direction (i.e. if an increasing CVT shortens or stretches the time parameter in question)
• Envelope LED display
• Attack time range: ~ 1ms ... 5 sec (can be extended by using the CVT input)
• Decay/Release time range: ~ 1ms ... 15 sec (can be extended by using the CVT input)