Amps and modulation
Just as the oscillator will flow to the filter, so the filter flows to the amplifier section. (See diagram on the left.) This is often intrinsically linked with an element described as an envelope. These are incredibly useful and used to apply what is known as modulation to an element of your synth sound. (There’s more on modulation in the box on the previous page.) In the most common scenario, you may see the letters ADSR (Attack, Decay, Sustain, Release) residing in the amplifier section, which makes perfect sense, as they control the volume (or amplitude) of your sound as it is played.