“Arch” 424 is a voltage-controlled oscillator. This VCO’s frequency range is wide, Can be used as VCLFO. It can produce four waveforms simultaneously: square, sawtooth, triangle, PWM and sine wave (sawtooth shape is not perfect yet). The frequency or pitch of the VCO is determined by tuning (Pitch and Fine) knob, and by the voltage present at the CV inputs.
You can control the pulse width of the square wave either by hand, or by voltage control – Pulse Width Modulation or PWM.
If perfect pitch is required better VCO is recommended. For a perfect sawtooth this is not recommended.
VCA 424 provide voltage-controlled amplification.
The amount of amplification the VCAs provide is determined by the voltage at the CV input, and the position of the gain control, which sets the overall gain in the system.
The VCA has 4 audio inputs, each with an attenuator. They are amplified by an amount determined by the combination of the gain and the 4 CV controls. OTA based.