Pittsburgh Modular Microvolt 3900, Manual

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The Microvolt 3900 is a patchable, analog synthesizer. It combines the functionality of 11 individual synthesizer
sections. The sections are internally connected to create a fully functional signal path without the need for patch
cables, however 39 patch points are available to connect different synthesizer sections using
1/8” mono patch
cables to create custom sounds and textures.
The Microvolt 3900 signal path is divided into two basic types of signals: audio signals and control voltages.
The audio signal carries the sound that is produced through the synthesizer. The audio signal path starts at the
voltage controlled oscillator before passing through other synthesizer sections used to shape the sound such a
mixer, filter, and VCA. Audio signal levels vary depending on their location in the signal path. This allows each
synthesizer section to have the perfect signal level for the desired sonic results. Detailed information on each
section can be found later in the manual.
Control voltages (CV) is a static or variable DC or AC voltage used to indirectly manipulate the audio signal by
controlling the circuitry that processes the audio. This can be done using a few different types of CV. Gates are
represented by a high or low control voltage to create a binary on or off state. A gate can be generated using a
pulse or square wave from an oscillator or modulation source, or by using the gate or clock output from the midi
module. A gate can be shaped using the function generator or envelope generator to create more complex
control voltage (CV) signals. A gate signal or CV signal can be patched to any CV input on the Microvolt 3900 to
be used as a modulation source. For example, a CV signal from the output of the function generator patched into
the FM input of the oscillator section controls the frequency of oscillator based on the current state of the function
generator.
Don ’ t forget, audio signals can be used as a control voltage source too. Audio rate modulation is always an
interesting world to explore.
3. Microvolt 3900 Connections and Signals