Voltage Standard

The pitch keeps the synth harmonically stable and ready to blend with other instruments.

To achieve this stability, Eurorack systems keep their oscillators in tune using the 1 V/oct standard – each additional volt raises the pitch by exactly one octave. This concept goes back to Robert Moog, who wanted tuning to feel musical rather than purely technical. He reasoned that musicians think in terms of intervals – it doesn’t matter to them that 440 Hz is one octave lower than 880 Hz.

In the 1 V/oct system, oscillator frequency follows the relationship f ∝ 2^V. In other words, each extra volt doubles the frequency (one octave up), while subtracting a volt halves it (one octave down). This makes it easy to transpose pitches without retuning the entire patch.

Another reason for using 1 volt as a reference is that it offers sufficient accuracy to control oscillators via potentiometers and keyboards, while keeping the voltage low enough that a range of 4–5 octaves does not require something like 20 volts.

1 V/Oct

= Pitch Control

Standard

5 V

≈ Gate

(not fully standard)

10 Vpp

≈ for Audio

(not fully standard)

For gate and trigger signals, an informal standard has emerged at around 5 V. However, this is not fully standardised and may vary between manufacturers, so always check your manuals to confirm the signal types your modules require or produce.

Audio signals also follow certain standards. The waveforms typically fluctuate between -5 V and +5 V, giving a 10 V peak-to-peak range. This provides enough headroom when voltages are mixed and add up.

Voltage Standard

The pitch keeps the synth harmonically stable and ready to blend with other instruments.

To achieve this stability, Eurorack systems keep their oscillators in tune using the 1 V/oct standard – each additional volt raises the pitch by exactly one octave. This concept goes back to Robert Moog, who wanted tuning to feel musical rather than purely technical. He reasoned that musicians think in terms of intervals – it doesn’t matter to them that 440 Hz is one octave lower than 880 Hz.

In the 1 V/oct system, oscillator frequency follows the relationship f ∝ 2^V. In other words, each extra volt doubles the frequency (one octave up), while subtracting a volt halves it (one octave down). This makes it easy to transpose pitches without retuning the entire patch.

Another reason for using 1 volt as a reference is that it offers sufficient accuracy to control oscillators via potentiometers and keyboards, while keeping the voltage low enough that a range of 4–5 octaves does not require something like 20 volts.

1 V/Oct

= Pitch Control

Standard

5 V

≈ Gate

(not fully standard)

10 Vpp

≈ for Audio

(not fully standard)

For gate and trigger signals, an informal standard has emerged at around 5 V. However, this is not fully standardised and may vary between manufacturers, so always check your manuals to confirm the signal types your modules require or produce.

Audio signals also follow certain standards. The waveforms typically fluctuate between -5 V and +5 V, giving a 10 V peak-to-peak range. This provides enough headroom when voltages are mixed and add up.

Manual Area

These guides are part of our effort to share practical knowledge about DIY synth building, tools, and Eurorack standards. We want them to be as clear and useful as possible, and we know there’s always room for improvement.

Your feedback matters

If you spot an error, think something could be explained better, or want to share your own DIY tips, please let us know. You can reach us at shop@exploding-shed.com or through our contact page .

Manual Area

These guides are part of our effort to share practical knowledge about DIY synth building, tools, and Eurorack standards. We want them to be as clear and useful as possible, and we know there’s always room for improvement.

Your feedback matters

If you spot an error, think something could be explained better, or want to share your own DIY tips, please let us know. You can reach us at shop@exploding-shed.com or through our contact page .