Module A-110 is a voltage-controlled oscillator. This VCO's frequency range is about eight octaves (ca. 15Hz ... 8kHz). It can produce four waveforms simultaneously: square, sawtooth, triangle, and sine wave.
Module A-140 is an envelope generator, and, since it puts out control voltages, counts as one of the modulation devices in a modular system. As soon as the gate input receives sufficient voltage, the ADSR generates a variable voltage, changing in time, called an envelope.
Module A-141 (VCADSR) is the voltage controlled version on an ADSR type envelope generator - a bit like the the voltage controlled version of the A-140. Whenever a gate signal is sensed at the VCADSR's gate input, an adjustable sequence of voltages is triggered - the envelope.
This module is a two-channel headphone amplifier with two audio inputs with level controls. Input 1 is normalled to Input 2. A common loudness/master knob controls the level with max. output power ~ 2 W per channel (@ 8 Ohm load).