The moogerfooger CP-251 Control Processor is a collection of classic basic circuits for generating, modifying, combining, and distributing control signals. Used in connection with one or more moogerfooger analog effects modules or other voltage-controlled gear, the CP-251 forms a modular analog synthesizer system, with the same kind of power and versatility of the classic MOOG modular synthesizers.

Extended information

What is a Control Processor?
There are two kinds of signals in a modular analog synthesizer: audio and control. As audio signals go through a system of synthesizer modules, they get shaped into the sounds that you hear. Control signals, on the other hand, correspond to the variations in the sound that are imparted by the synthesizer modules, like invisible hands that turn the knobs of the modules. The CP-251 gives you a bank of control signals and lots of ways to modify, mix, and distribute them to product the myriad dynamic effects that analog synthesizers are famous for.

Technical specifications

FOUR INPUT MIXER - Enables you to combine control signals to create complex effects.
LAG PROCESSOR - Reshapes control signals by slowing down abrupt changes, used to produce glides and swoops.
LOW FREQUENCY OSCILLATOR (LFO) - Makes periodic control signals over the range of one cycle every five seconds to 50 cycles per second. The LFO is itself voltage-controlled so you can vary its rate with an expression pedal or other control signal to create effects such as vibrato, warbles, and sirens.
Two ATTENUATORS - To reduce the strength of control signals, enabling you to adjust the strength of an effect.
FOUR-WAY MULTIPLE - Enables you to send one control signal to as many as three destinations.
NOISE SOURCE - Provides pure noise for use as an audio or control signal.
SAMPLE AND HOLD - Produces stepwise control signals by sampling the voltage of any signal at rate of the LFO to produce classic sample-and-hold effects. This circuit also has a second output which is a smoothed version of the stepwise output.