MODULAR MASTER CLASS
The voltage-controlled amplifier
You might think that the simple voltage-controlled amplifier, or VCA, is a simple volume controller, but think again. VCA equals VC hey!
>At first glance, the voltage-controlled amplifier – or VCA – seems to hold little interest, residing in its usual spot somewhere near the end of the signal path. We take it for granted – in fact, though a crucial component in any analogue synth, it’s often hidden behind the curtain, dutifully performing only its most obvious task: governing volume. Many instruments don’t even bother to label it on the front panel – as a result even a seasoned synthesist might not even consider its existence, never mind its potential usage.
Modular synthesists, on the other hand, are well aware of the significance of the humble VCA and hold it in high esteem. “You can never have enough” is an oft-repeated adage among the patch cord cognoscenti, and for good reason. For the modular synthesist, VCAs are as important to signal routing as signal lights are to the flow of traffic. They control not only the volume of signal flowing between a source and destination, but timing as well.
In this month’s tutorial – the first of two – we’ll take a look at the voltage-controlled amplifier using the VCA module included with Cherry Audio’s Voltage Modular Nucleus. We’ll run through its two most common applications: to control audio signals as well as voltages. Next month we’ll take a deeper dive into some more esoteric uses of the not-so-humble VCA.