Again, high amounts of jitter create distortions in the reconstructed waveform, as well as the aforementioned points about a reduction in the depth and detail of the recording.
This time the clock is involved with the reconstruction of the signal, outputting the series of stepped binary messages as a continuous analogue waveform. Turning to the D/A conversion process, clocking has an equally important role to play. As well as the unwanted distortion and noise, problematic amounts of jitter can have a big impact on the depth and detail in a recording, with an increasingly unfocused soundstage that affects elements such as reverb tails and other more discrete parts of the mix.
If the A/D converter was presented with a sine wave, for example, any drift within the clock – technically known as jitter – would create small but tangible amounts of waveform distortion heard as noise, which ultimately inhibit the quality of the recording we capture. The qualitative impact of clocking becomes apparent when we start to consider what happens if the divisions of time aren’t 100% accurate – in other words, if the clock ‘drifts’ slightly. To achieve such fine divisions of time A/D converters rely on small piezoelectric quartz crystals, much the same as the quartz crystals found in digital wristwatches. To digitise an analogue signal its amplitude is sampled thousands of times each second – usually 44,100 or 48,000 times depending on your chosen sample frequency.
In the case of A/D conversion, we need to transform a continuous analogue waveform into a stepped binary code – or a series of digital zeros and ones, in other words. However, with multiple protocols to cope with and a variety of approaches on offer, the role and impact of digital clocking can seem bewildering.Ĭlock works To understand the role of clocking, we need to take a deeper look the processes of A/D and D/A conversion. Understanding the qualitative impact of digital clocking, therefore, and how it integrates into the modern studio is an essential part of an engineer’s skill set.
Whether you’re using a simple computer-based setup with a single audio interface or a complete digital production suite with multitrack recorders, a console and an effects unit all digitally connected, the way that your system is clocked can have a significant impact on the quality of your recordings.