PROBZ – Probabilistic Note and Gate Processor

PROBZ is a probability-based utility module that decides whether incoming note events are allowed to pass. It is designed for melodic variation, rhythmic thinning, generative sequencing, and controlled randomness. Each lane listens for an incoming gate, evaluates a probability setting, and then either lets that event happen or blocks it. When an event is accepted, the current pitch is captured and sent to the output. When an event is rejected, no new gate is produced, and in HOLD mode the previous accepted pitch remains held. This makes PROBZ especially useful for turning regular sequences into evolving patterns without losing musical structure.

Global Active Control

The ACTIVE control determines whether PROBZ is processing signals or bypassed. When ACTIVE is set to ON, the module operates normally and all probability logic is applied. When set to OFF, the module is bypassed and all lanes pass their signals directly from input to output without any probability processing. This allows PROBZ to be enabled or disabled instantly during performance or sequencing. The ACTIVE state can be controlled manually using the button or remotely via the BYPASS input. A trigger on the BYPASS input toggles the state between ON and OFF.

General Operation

Each lane has a PITCH input, a GATE input, a PROB control, a PITCH output, and a GATE output. The module watches the incoming gate signal and reacts on the rising edge. At that moment, PROBZ performs a probability check. If the event passes, the lane becomes active for that gate and a new output gate is produced. At the same moment, depending on the selected pitch mode, the pitch is either captured and held or simply passed through continuously. If the event fails the probability check, no output gate is generated for that event.

Inputs and Outputs per Lane

Each numbered lane contains two inputs on the left and two outputs on the right. The PITCH input expects a pitch CV source, such as a sequencer, quantizer, keyboard CV, or any other control voltage used to define note pitch. The GATE input expects a trigger or gate that defines when a note event occurs. On the output side, the PITCH output provides either the held accepted pitch or the direct incoming pitch, depending on the selected mode. The GATE output sends a clean output gate only when the lane has accepted the incoming event.

PROB Controls

Each lane has its own PROB knob. This sets the chance that an incoming gate event will be accepted. At 100%, every gate event passes. At 0%, no events pass. Intermediate values create controlled variation. Because the decision is made only on the rising edge of the gate, the result is stable and musical. PROBZ does not constantly flicker a gate on and off. It decides once per incoming event and then keeps that decision for the duration of that gate.

Pitch Handling

PROBZ does not generate pitch by itself and does not quantize, transpose, or harmonize incoming notes. Its role is to decide whether a note event updates the lane or not. That means the pitch behavior depends entirely on the selected pitch mode.

Pitch Mode: HOLD

In HOLD mode, pitch is only updated when an incoming gate event is accepted. At that moment, the current pitch input is sampled and stored. That stored pitch is then held at the PITCH output until a later accepted event replaces it. This creates a true note-based probability behavior. If an event is rejected, the old pitch remains at the output, but no output gate is produced. Musically, this often results in repeated notes, stable held tones, and more coherent melodic reduction. HOLD mode is usually the most useful mode for melodic sequencing.

Pitch Mode: THRU

In THRU mode, the pitch output always follows the input pitch continuously, regardless of whether events are accepted or rejected. Probability only affects the output gate. This means the melodic source keeps moving, but only some gates are allowed through. THRU mode is useful when you want rhythmic probability while preserving the original pitch stream. It can also be useful when the pitch source is changing independently and you want PROBZ to affect articulation rather than note selection.

Detune

The DETUNE control adds a small random pitch offset to accepted notes. This only affects newly accepted events in HOLD mode. Each successful note can receive a subtle random deviation, making repeated patterns feel less rigid and slightly more organic. At very low settings this can give a gentle analog-style instability. At higher settings it becomes more obvious and can push sequences away from exact tuning. Because detune is applied per accepted note and then held, the result stays stable for that note instead of wobbling continuously.

Gate Behavior

The output gate is created only when an incoming event is accepted. Rejected events produce no output gate. The output gate follows the duration of the accepted incoming gate rather than creating a new arbitrary pulse length. This keeps timing aligned with the original source and makes the module easy to use with envelopes, drum voices, sequencers, and note-based patches.

Lane Usage

Each lane is independent. You can use different pitch sources and different gate sources per lane, or feed several lanes from related sources. This makes PROBZ useful both as a melodic thinning module and as a multi-lane rhythmic decision processor. Some users may choose to send the same sequence into several lanes with different probability settings, while others may assign each lane to a different voice or pattern source.

COMBI Section

The COMBI section creates two additional derived outputs from the lane gate signals. These are not pitch processors. They work only from the accepted gate states of the main lanes. Each COMBI row lets you choose up to three source lanes and combine them with a selected logic mode. The resulting combined signal is then passed through its own probability stage before reaching the COMBI output. This creates a second layer of controlled randomness and makes the module especially useful for complex rhythmic variation and polyrhythmic structures. When the module is set to OFF (bypassed), the COMBI outputs are disabled.

COMBI Source Selection

Each COMBI row includes three source selectors. These allow you to choose which lane gates are used as inputs for that COMBI row. A source can be set to OFF or to one of the lane numbers. OFF means that source is ignored. The COMBI logic only works from the lanes selected there. These selectors do not read pitch and do not create notes by themselves. They only use the accepted gate activity coming from the main lanes.

COMBI Modes

The mode selector defines how the chosen source lanes are combined. In OR mode, the COMBI output becomes active if any selected source lane is active. In AND mode, the COMBI output becomes active only if all selected source lanes are active at the same time. In XOR mode, the output becomes active when an odd number of selected source lanes is active, which can produce shifting and less predictable rhythmic relationships. In SUM mode, the output becomes a scaled combined level based on how many selected lanes are active. SUM is therefore less like a strict logic gate and more like a density-derived CV or weighted activity signal.

COMBI Probability

Each COMBI row also has its own probability control. After the selected lane gates are combined by the chosen mode, PROBZ evaluates that combined event and decides whether it should pass. This means COMBI is not just a passive mixer of lane gates. It is an additional probability layer. You can therefore first thin or vary the main lanes, then combine them, and then probabilistically filter the result again. This allows very rich rhythmic behavior from relatively simple source material.

What PROBZ Does with Pitch

A useful way to understand the module is this: PROBZ does not shape pitch continuously, it decides when pitch updates are allowed to matter. In HOLD mode, pitch only changes when an accepted gate event occurs. In THRU mode, pitch is always present, but gate probability determines whether that pitch actually creates an articulated note event downstream. This distinction is central to how the module behaves in musical patches.

Typical Uses

PROBZ can be used to add variation to regular step sequencers, thin dense trigger streams, create repeated-note behavior from melodic lines, generate evolving patterns from fixed material, derive new rhythmic outputs from several related lanes, and build generative patches that remain musically tied to the original sequence. It is especially effective when combined with sequencers, quantizers, arpeggiators, clocked gates, note CV streams, or any patch where too much repetition makes the result feel static.

Using HOLD Mode in Practice

HOLD mode is usually the best choice when the goal is melodic probability. Because rejected events do not update the held pitch, successful notes can repeat naturally. This makes phrases feel reduced, reshaped, or selectively remembered rather than simply muted. If you want a sequence to become more sparse but still feel melodically intentional, HOLD mode is usually the strongest option.

Using THRU Mode in Practice

THRU mode is useful when you want the pitch stream to remain untouched while only the note articulation becomes probabilistic. In this mode, the pitch output may continue to move even during rejected events, so the downstream result depends more heavily on what uses the gate output. THRU mode is often better when pitch should remain externally visible or when you want rhythmic filtering without introducing held-note repetitions.

Using Detune in Practice

A small amount of detune can make repeated accepted notes feel less mechanical. This is especially effective in HOLD mode, where sequences may otherwise become very exact. Subtle settings are usually the most useful. Larger settings can be used deliberately for unstable, rough, or more experimental melodic behavior. If exact tuning is important, keep DETUNE low or fully off.

Using the COMBI Section in Practice

The COMBI outputs are especially useful for creating secondary trigger streams, ghost rhythms, accent structures, or denser or sparser derived patterns. Because the source material is taken from already accepted lane gates, the COMBI section reacts to the musical behavior of the lanes rather than to the raw input gates. This makes it an excellent tool for creating related but not identical rhythmic structures from the same patch.

Important Behavioral Notes

Probability decisions are made on gate rising edges, not continuously. Rejected events do not create output gates. In HOLD mode, rejected events do not update the held pitch. In THRU mode, pitch is not held and continues to follow the input. COMBI outputs are based on lane gate activity only and do not process pitch. SUM mode in COMBI behaves differently from strict gate logic because its output level depends on how many selected lanes are active. When ACTIVE is OFF, all lanes pass signals directly and COMBI outputs are muted.

Summary

PROBZ is a flexible probability processor for note and gate material. At its core, it decides whether incoming events should happen, and this simple idea opens up a wide range of musical uses. It can turn rigid sequences into evolving phrases, create repetitions from skipped notes, preserve melodic logic while reducing density, add gentle humanized detune, and build new rhythmic layers from accepted lane activity through the COMBI section. The ACTIVE control allows instant switching between full processing and direct pass-through, making PROBZ equally useful as a creative tool and a performance-friendly utility.