Oscilloscopes

Oscilloscopes are one of the most important tools for electronic testing and signal analysis, allowing waveforms to be visualised in real time. Originally developed as hardware units, oscilloscopes were primarily designed for engineers to test the functionality of electronic circuits on a variety of gear (not just for audio and not just operating in the audible frequency range). They are often used with function generators – similar to synth oscillators, but with a much higher frequency range – which feed a test waveform into the circuit.

For audio purposes we already have a waveform to test – the audio signal itself – but not all signals are suitable for oscilloscopes. Oscilloscopes tell us most about signals of relatively stable frequency, amplitude and harmonic content. With these signals we can synchronise the oscilloscope’s scan period with the frequency of the wave, making the waveform appear stationary on the display (most software scopes will do this automatically).

Want to check the inaccuracies that make one synth’s raw square wave sound fatter than another’s? Want to see how a lowpass filter rounds off the shape of that square wave until it’s a pure sine? How a distortion effect turns that sine slowly back into a square as you crank up the gain? You need an oscilloscope.

It’s the best way to visualise that kind of simple process. Oscilloscopes aren’t the kind of equipment you’d use every day, but for visualising simple signals in real time they’re unbeatable and a great tool for learning about synthesis.

Blue Cat’s Oscilloscope Multi (bluecataudio.com), is still a decent example, and available for all platforms, for $49.

If you want to get technical and really see what’s going on at the heart of your track, invest in a specialist oscilloscope