The Essential Guide To DCO vs VCO

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  • Learn the difference between a DCO and VCO
  • We break down both devices and their uses
  • Find out which is best for you
  • Also, check out our post on modular synthesis basics

Oscillators are an incredibly crucial component in many applications. They can emit one of the common wave shapes, including square, sine, and triangle.

This gives us a signal we can use to edit other audio waves. We use these for computers, telecommunications, synthesizers, and other electronic appliances. 

Let’s compare both devices and discuss their uses.

What Is A DCO?

DCO stands for Digitally Controlled Oscillator. This device produces an audio signal that you can edit using an independent circuit.

That means, with a few clicks of a button, you can change the frequency of a wave. The pitch is directly proportional to the rhythm of a signal. 

So, when you increase the frequency of the oscillator, the pitch will escalate. However, the DCO can’t alter the filters that shape the signals digitally.

So, some people consider its operation half digital and half analog.

Uses of DCO

There are DCOs in many of the electronic devices around us. Some examples include:

  • Synthesizers
  • Microcontrollers
  • Software-defined radios

All these gadgets rely on DCOs to function. They maintain the pitch of the internal structures of a device to keep them running smoothly.


  • Able to overcome tuning stability limitations with ease
  • Can emit stable signals at a constant frequency
  • Controls don’t require any previous knowledge of voltage and frequency correlation


  • Susceptible to substrate-induced noise
  • Consumes large amounts of power quickly

What Is A VCO?

VCO stands for Voltage Controlled Oscillator. As you can guess by the name, we use voltage to alter the output signal of the device.

As you increase the voltage input to the oscillator, the frequency will change. This allows you to edit any output audio signal manually.

Just like DCOs, VCOs can’t change the shaping filters automatically. That means that this device can only affect the pitch, not the timbre.

The timbre deals with the overall sound quality of an audio wave. We change it by manipulating the original shape of the oscillator wave.

Uses of VCO

While VCOs are a little less common than DCOs, we still use them frequently. Here are a few devices that rely on VCOs:

  • Function generators
  • Phase-locked loops
  • Frequency synthesizers

Because of the distorted nature of the waves a VCO produces, many people like to use it for electronic music. 


  • Provides frequency stability with reference to the power supply
  • Reduces noise and temperature fluctuations
  • Controls the frequency accurately


  • Difficult to implement using integrated computers
  • Controls can be slightly finicky

DCO vs. VCO: The Final Verdict

You now know that each oscillator type uses a different control mechanism. However, figuring out how this translates into the real world can be a little tricky.

When you run the same audio signal through a DCO and a VCO, you’ll hear the distinction. DCOs produce a static sound, which means that the signal doesn’t change with time. This will give you a uniform output.

As for VCOs, they create dynamic signals. Because the voltage input lacks certain stability, the wave is constantly changing. This gives an overall choppy or electronic-sounding signal. 


Can I Use DCOs and VCOs Interchangeably?

The simple answer is yes. Both devices perform a similar function, so it’s possible to substitute one for the other. 

Although, you have to keep in mind that the output audio will be a little different.

Why Are VCOs Generally More Expensive Than DCOs?

Typically, VCOs are a little more challenging to produce. That’s why they tend to be slightly pricier than DCOs.

Plus, many music lovers prefer the audio quality of VCOs, which means there’s a higher demand.

Are DCOs More Reliable Than VCOs?

While DCOs have more stable signals, that doesn’t mean their operation is reliable. That will depend on the make and brand of your device.

So, when choosing between VCOs and DCOs, focus on sound quality. Listen to a few examples of both and pick the one you like the best.

Wrapping Up

Deciding between DCO vs. VCO can be tricky, so you have to consider a few factors. First off, you should know that both of them perform the same basic function using an oscillator.

The major difference between them is the controls. VCOs rely on voltage, while DCOs change digitally.

Each one will produce sound with unique qualities. So, which device you choose will depend on your preferences.

Before you go, check out our guide to the 9 Best Free Synth VSTs In Existence!