An Introduction to Modular Patching
The Pittsburgh Modular Patch Box Modular Effects Enclosure offers unique access to a wide variety of analog and digital modular effects. Total control of not
only the audio path but also a layer of voltages used to control the parameters of the installed effects modules.
Once the effects modules are added, plugging in a few patch cables opens the Pittsburgh Modular Patch Box to complex experimentation by offering unlimited
control over both the control and audio signal paths. Assigning controls to one of the external expression pedal inputs, or rerouting audio or control signals
using the patchable footswitches opens up a new world of hands free, sonic manipulation.
The Patch Box signal path is divided into two types of signals: audio signals and control voltages. The audio signal is the sound that is produced. The audio
signal path starts at a sound source. This can be the 1/4’ audio input jack, LFO running at audio rate, or the resonance of a self oscillating filter. The audio
signal is then patched through other modules used to shape the sound such a filter, delay, crusher, reverb, phase shifter, or other effects module.
Control voltages (CV) manipulate the audio signal in several different ways. Gates are represented by a high (on) or low (off) control voltage. A gate can be
generated using a pulse or square wave from an LFO (low frequency oscillator), or by using the gate output of an envelope follower module. A gate signal can
be sent to the CV input of any module. Modulation sources can be static DC voltages from an expression pedal or variable AC voltages such as an LFO or
audio signal. As an example, a control voltage from the output of an expression pedal can be patched into the frequency cutoff CV input of a Filter module to
create a traditional wah-wah effect. Modulation can also come from a low frequency oscillator (LFO) module or the output of an envelope follower. Using an
envelope follower such as the Pittsburgh Modular Detect module, creates a modulation source based on the amplitude of the incoming audio signal. This
allows the performer to control any voltage controllable parameter with the variable loudness of a performance.
Audio signals also make a great control voltage source for more extreme modulation. As always, experimentation is essential to getting the most out of the
Patch Box and installed modules.
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