An analog synthesizer creates sound by driving oscillators, filters, and amplifiers with voltage. Its character is often described in terms of thickness, movement, and the way the filter responds. These days, alongside analog hardware built on real circuits, virtual analog instruments that reproduce that behavior in software are also widely used.
The basic signal flow
The oscillator generates a waveform such as a sawtooth or square wave, the filter shapes the brightness, and the amplifier controls the level. The envelope creates the change from pressing a key to releasing it. Understanding this flow helps you find a starting point for sound design on any model.
What analog character means
Variations between circuits, slight pitch drift, and the way the filter responds are among the things described as sounding analog. But analog does not automatically mean warm. Timbre is determined by the waveform, the filter, the settings, the performance, and the mix, so listen rather than judging by the label.
Relationship to software instruments
Analog modeling instruments inside a DAW recreate the behavior of analog circuits computationally. Unlike hardware, they make it easy to save and recall many patches and to combine with MIDI and automation. Understand what each instrument does well and choose what fits the song.
Sound design with the filter
Lowering a low-pass filter’s cutoff reduces the highs, and raising the resonance emphasizes the boundary. This is the classic analog synth move, but extreme changes also alter level and can create harsh peaks. Check that the change is one the song actually needs.
Making your first sound
Start with a single oscillator, choose a waveform, and listen with the filter open. Then move the cutoff and the envelope a little at a time. The basics of working with instruments in a DAW are covered in the software instrument article.
