F_CMPRZ

CMPRZ – Dual Threshold Comparator & Register Splitter

CMPRZ is a precision voltage comparator designed to extract musical structure from pitch or control voltage sequences. It divides an incoming signal into three dynamic zones (LOW, MID, HIGH) based on two adjustable thresholds. From a single pitch sequence you can generate independent pitch streams, gates, zone-enter triggers, and directional crossing triggers. CMPRZ turns one melodic line into multiple musical layers without duplicating sequencers.

Concept

The module continuously compares the input voltage to two threshold values: LOW and HIGH. These define three regions. The LOW zone contains all voltages below the LOW threshold. The MID zone contains all voltages between LOW and HIGH. The HIGH zone contains all voltages above the HIGH threshold. Each zone produces its own pitch output, gate output, and trigger behavior. This allows you to split one melodic CV stream into bass, mid voice, and lead registers, or to create structural events when a melody crosses specific pitch boundaries.

Input

The IN jack accepts pitch CV or any control voltage. CMPRZ is especially powerful with 1V/Oct pitch sequences, but it works equally well with modulation sources, envelopes, LFOs, or stepped voltages. The module operates purely on voltage comparison and does not assume musical note names internally.

Threshold Section (THR)

The LOW and HIGH knobs define the two threshold voltages in Volts. LOW sets the lower boundary and HIGH sets the upper boundary. If LOW is set higher than HIGH, the module automatically swaps their effective order internally to keep the MID zone valid. Thresholds can be modulated via the LOW_CV and HIGH_CV inputs. The L_AMT and H_AMT controls act as attenuverters, allowing positive or negative modulation depth. This makes it possible to move the zone boundaries dynamically with envelopes or LFOs, creating evolving register windows.

Pitch Outputs (PITCH)

P_LO, P_MID, and P_HI output the original input voltage only when the signal is inside the corresponding zone. Outside that zone, the output is 0V. This allows you to route each register to a different oscillator or voice. P_MIDC is a centered version of the MID zone pitch. When the input is inside the MID zone, P_MIDC outputs the input voltage minus the midpoint between LOW and HIGH. This means the MID range becomes centered around 0V, making it ideal for relative modulation, transposition layers, or symmetrical processing around a central pitch.

Gate Outputs (GATE)

G_LO, G_MID, and G_HI output a steady 5V gate whenever the input is inside the respective zone. These gates are stable due to hysteresis and are useful for switching signal paths, triggering envelopes, or controlling logic modules. Each gate represents a sustained state rather than a momentary event.

Zone Enter Triggers (ZONE ENTER)

T_LO, T_MID, and T_HI produce a short trigger pulse whenever the signal enters the respective zone. T_ANY produces a trigger whenever any zone change occurs. The TRG control sets the trigger pulse length in milliseconds. These outputs are ideal for accenting notes that cross into a new register, firing percussion when melodies jump ranges, or creating structural transitions in a patch.

Direction Triggers (DIRECTION)

L_UP and L_DN generate trigger pulses when the signal crosses the LOW threshold upward or downward. H_UP and H_DN generate trigger pulses when the signal crosses the HIGH threshold upward or downward. These triggers respond specifically to direction, not just zone entry. This makes it possible to react differently to ascending versus descending motion. For example, you can open a filter when a melody rises above the HIGH threshold and close it when it falls back below.

Hysteresis (HYS)

The HYS control adds hysteresis in Volts around both thresholds. Hysteresis prevents rapid switching when the input voltage hovers near a boundary. Instead of switching exactly at the threshold value, the signal must move slightly beyond it before a zone change occurs. This stabilizes gates and triggers and eliminates unwanted retriggering caused by small fluctuations or glide.

Trigger Length (TRG)

The TRG control sets the duration of all trigger pulses generated by CMPRZ. This includes the zone-enter triggers (T_LO, T_MID, T_HI, T_ANY) as well as the directional crossing triggers (L_UP, L_DN, H_UP, H_DN). The value is defined in milliseconds and determines how long each trigger output remains at 5V before returning to 0V.

A lower TRG setting produces short, sharp trigger pulses that are ideal for firing envelopes, advancing sequencers, or creating tight rhythmic events. Higher TRG settings generate longer pulses, which can be useful when driving modules that require a more clearly defined gate signal or when creating more pronounced rhythmic accents. TRG does not affect when a trigger occurs, only how long the pulse remains high.

Typical Applications

Use CMPRZ to split one sequencer into bass, harmony, and lead voices without copying patterns. Create dynamic register-based arrangements by sending LOW notes to a bass oscillator, MID notes to a pad, and HIGH notes to a lead synth. Use T_ANY to generate rhythmic accents whenever the melody changes register. Modulate thresholds with slow LFOs to create evolving harmonic windows. Use P_MIDC for centered modulation around a moving tonal window. Combine direction triggers with envelopes for expressive phrasing control.

Musical Strategy

CMPRZ works best when thresholds are placed deliberately within the musical range of the sequence. Think of LOW and HIGH not just as technical limits but as structural dividers of your composition. Subtle hysteresis values keep transitions clean while preserving responsiveness. When modulating thresholds, small modulation amounts often produce more controlled and musical results than extreme movement.

Summary

CMPRZ is more than a comparator. It is a register-aware routing and event generation system. By dividing a single voltage stream into zones with stable gates and expressive directional triggers, it enables complex musical behavior from minimal sources. Whether used for melodic splitting, structural event detection, or dynamic register modulation, CMPRZ adds intelligence and articulation to any patch.