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CP-251 Control Processor - Image 1

CP-251 Control Processor

DesktopAnalog

Back in 2000, this little box brought the modular magic of classic Moog systems into a compact, pedalboard-friendly package, letting you patch control voltages like it was 1965 all over again.

At its core, it's an analog CV powerhouse with a four-input mixer for summing signals (two with attenuators, plus offset and master controls for positive/negative outputs), a four-way multiple for splitting one signal to three destinations, and two dedicated attenuators to dial in just the right voltage amount. You'll find a voltage-controlled LFO pumping out triangle and square waves from 0.2 Hz to 50 Hz (with external rate modulation), a sample-and-hold circuit (triggered by the LFO or external source, with a filtered output), a white noise generator for random CV fun, and a lag processor that smooths voltage changes from instant to a full second per volt. Housed in a sleek half-rack (3U deep) metal chassis with wooden side panels, big Moog knobs, and 1/4-inch jacks (some for expression pedals), it runs on a standard 9V supply and patches via TRS or TS cables—no sound generation, just pure modulation muscle for Moogerfoogers, vintage synths, or anything CV-compatible.

Over the years, players have called it an essential CV toolkit—super versatile for wild filter sweeps, random delays, or pedal-controlled chaos, with fans loving its hands-on patching flow and build quality, though some note the lack of MIDI or memory as a vintage tradeoff.

Released

2000

Status

Discontinued

Synthesizer
Format
Desktop, Rackmount
Type
-
Internal Battery
No
Voice
A/D
Analog
Polyphony
-
Oscillators
-
Oscillator Type
-
Filter
No
Envelopes
-
LFO
1
Effects
No
Expression
Aftertouch
No
Velocity
No
MPE
No
Additional
-
Software
-
I/O
Audio In
-
Audio Out
-
Headphone
-
MIDI
-
MIDI Type
-
Ports
CV/Gate, Expression Pedal
Wi-Fi
No
Workflow
Arpeggiator
No
Sequencer
No
Mod Matrix
No
Memory
None
Measurements
Dimensions
-
Weight
-
Last updated Mar 15, 2026