A “bipolar signal” refers to an electrical signal that oscillates above and below a reference point, typically 0 volts. Bipolar signals can represent both positive and negative values and are commonly used for various purposes in modular synthesizers, such as modulation sources, control voltages (CV), and audio signals.
A bipolar signal can be visualized as a waveform that has both positive and negative peaks, crossing the zero-volt reference point. Some common examples of bipolar signals in modular synthesizers include:
- LFOs (Low-Frequency Oscillators): LFOs produce bipolar signals that can be used to modulate parameters like oscillator pitch, filter cutoff frequency, or amplifier gain, creating effects like vibrato, wah, or tremolo.
- Envelope generators: Some envelope generators produce bipolar signals, which can be used to modulate parameters in both positive and negative directions, providing more complex modulation possibilities.
- Audio signals: Audio signals from oscillators or other sound sources in a modular synthesizer are typically bipolar, as they represent the oscillation of sound pressure above and below the reference point.
Bipolar signals are often used for modulation and can produce a wide range of effects and timbres, depending on the parameter being modulated and the characteristics of the bipolar signal itself.
When using bipolar signals, it’s essential to consider the destination module’s input requirements, as some inputs may only accept unipolar (positive-only) signals. In such cases, you may need to use an offset or attenuverter module to adjust the bipolar signal to match the destination module’s input requirements.
