Capacitors feature prominently in the world of audio engineering. These unassuming-looking components have the ability to smooth out noisy signals, maintain power during peak loads, and help create the sounds we know and love. Audio-grade capacitors span a variety of applications. Let's explore some of the uses for audio capacitors in audio engineering applications.
Traditional audio circuitry: how capacitors affect sound
Capacitors store electrical energy. You can find them at work in nearly all modern electronic devices. In audio amplification applications, capacitors couple the constant DC signals with the rapidly fluctuating voltages that drive speakers to help create a smooth sound. To create a bold and clean sound, larger capacitors work better than smaller ones. A large capacitance decreases the audio circuit's impedance, limiting the amount of noise between the power supply and the actual audio driving circuitry and ultimately leading to clear, unaltered sound.
High-end audio capacitors: better sound quality
In addition to having a large capacitance, the materials used in the construction of audio-grade capacitors must be designed to have low impedance. For example, some lower-grade capacitors utilize steel or aluminum leads, while high-accuracy audio-grade capacitors contain high-conductivity copper leads. Additionally, the capacitor's dielectric material directly influences its capacitance. In many cases ― mostly high-end electrolytic capacitors ― the proprietary dielectric material inside an audio-grade capacitor is meticulously manufactured to create robust, high-capacitance capacitors.
An audio-grade capacitor's goal is to minimize the amount of distortion and feedback between the audio and power signal. In short, the higher the quality of the capacity, the better the sound will be.
Capacitor tolerance matters
You may be thinking: as long as I purchase a high-quality capacitor that meets the circuit's specified capacitance, I'll be able to produce a full-bodied sound, right?
Not necessarily. Consider the tolerance of a capacitor's capacitance, especially in tone control applications. A capacitor with a tight tolerance (low range) will maintain the specific capacitance during use, whereas loose tolerance capacitors may sound different if you are playing indoors or outdoors. Given that capacitors are made from a multitude of materials ― all of which are subject to external influence ― different capacitor types and manufacturers will ultimately sound different, even if they meet the same specs on paper.
Capacitor types: high end audio capacitors
For example, the famous Orange Drop capacitors from Cornell Dubilier (CDE, and formerly Sprague) were used to create the famous Gibson guitar's vintage sound in the 1950s. Gibson used them again in its Holy Grail guitar line starting in 2014. Orange Drop capacitors have made their way into the mainstream ― and many consider them the magic that defines the Gibson sound ― but their true fame lies in their performance stability and resistance to external influences, such as temperature and moisture.
Conclusion
When it comes to utilizing capacitors in audio applications, the sky is the limit. Creating unique sounds hinges on the fundamental principles that define capacitor technology, and exploring the variations in these principles can lead to a robust understanding of audio engineering.
