# Centreville — PlusMix - [Manual PDF](../../manuals/PlusMix _ centrevillage.pdf) --- [Manual / Product Page PDF Source](https://centrevillage.net/products/PlusMix.html) # centrevillage PlusMix — melodic use analysis The attached manual describes **PlusMix**, a **2HP unity mixer with gate-controlled switching**. It is small, but very useful for building **melodic variation, transposition, phrase selection, and pitch recombination** in a Eurorack system. ## What the module does ### Inputs and outputs - **Inputs** - `BASE` - `PLS1` - `PLS2` - `SW1` gate input - `SW2` gate input - **Output** - `MIX` ### Core behavior - `BASE` is **always present** at the output. - `PLS1` is added to the mix only when its gate logic condition is true. - `PLS2` is added to the mix only when its gate logic condition is true. ### Gate logic Each switched layer has: - a gate input (`SW1`, `SW2`) - a polarity switch (`SW1PL`, `SW2PL`) A `PLS` signal is mixed when: - the corresponding gate is **HIGH** and the polarity switch is set to **H**, or - the corresponding gate is **LOW** and the polarity switch is set to **L** So each added signal can be made active on: - gate high - or gate low ### Normalization - `SW1` is normalized to **+5V** - `SW2` is normalized to **SW1** This means: - with nothing patched to `SW1` or `SW2`, the polarity switches act like **manual on/off selectors** - with a gate patched only to `SW1`, both `PLS1` and `PLS2` can follow that gate unless `SW2` is separately patched --- ## Why this is musically important for melody Because PlusMix is a **precision CV mixer**, it is especially useful for **pitch CV**. That means you can combine voltages representing notes, intervals, or transpositions without the slop that would make melodies go out of tune. In practice, that makes PlusMix great for: - **adding intervals to a base melody** - **switching transpositions in and out** - **creating A/B melodic variants** - **building call-and-response phrases** - **adding octave jumps conditionally** - **making rhythmic melodic accents from gates** - **recombining multiple pitch sources into one melodic line** --- ## Best melodic roles for PlusMix ## 1. Conditional transposition mixer Use `BASE` for your main pitch sequence, and use `PLS1`/`PLS2` for interval offsets. Example: - `BASE` = main sequencer pitch - `PLS1` = +1V octave transpose - `PLS2` = +0.583V approximate perfect fifth if your source can generate exact interval CV - `MIX` → oscillator 1V/oct Then use gates into `SW1` and `SW2` to decide when those intervals are added. Result: - melody plays normally sometimes - jumps up an octave on selected steps - adds another interval on other steps - can combine both for larger jumps This is one of the most direct ways to create **melodic contour variation** from a static sequence. --- ## 2. Phrase variation from gate patterns Feed the same melodic base into `BASE`, then patch offset voltages or alternate melodic fragments into `PLS1` and `PLS2`. Example: - `BASE` = 8-step sequence - `PLS1` = small offset, like +2 semitones - `PLS2` = another offset, like -3 semitones - `SW1` = gate pattern from a trigger sequencer - `SW2` = slower gate or clock division Result: - certain notes are pushed upward - certain notes are pulled downward - repeated patterns become evolving phrases This creates **motivic development** without needing a second full sequencer. --- ## 3. Manual performance transposer Because of the normalization, if no gates are patched: - `SW1PL` and `SW2PL` become manual enable/disable switches for `PLS1` and `PLS2` Example: - `BASE` = running melody - `PLS1` = +12 semitones - `PLS2` = +7 semitones Now the two switches become immediate performance controls: - enable octave - enable fifth - enable both for a larger harmonic lift This is excellent for: - live arrangement - moving between verse/chorus - introducing fills - changing melodic register on the fly --- ## 4. Gate-defined note accents Use a rhythmic gate source to add pitch only on selected steps. Example: - `BASE` = root note sequence - `PLS1` = +2 semitones - `SW1` = snare-related trigger pattern or Euclidean rhythm Result: - the melody “leans” into accented notes only when the gate is present This is useful for: - syncopated hooks - acid-style step accents - dynamic lead lines with repeating structure --- ## 5. Recombining quantized pitch sources PlusMix can combine several pre-shaped CV sources into one line. Example: - `BASE` = slow quantized melody - `PLS1` = stepped random voltages scaled to chord tones - `PLS2` = manual offset from a precision adder, keyboard, or fixed voltage source Use gate inputs to bring these layers in and out. Result: - one coherent melodic output with controlled variation - a hybrid between sequencing and performance patching --- # How to use it with other modules to build melodic components The manual only covers PlusMix, but in a normal Eurorack melodic patch it pairs especially well with the following module types: ## With a sequencer Use the sequencer as the main pitch source. Patch: - sequencer pitch → `BASE` - fixed voltage / second sequencer row / transpose CV → `PLS1` - another offset or phrase row → `PLS2` - sequencer gates / trigger track → `SW1`, `SW2` - `MIX` → quantizer or directly to oscillator Musical result: - one sequence becomes multiple melodic variants - you can derive several phrases from one pitch lane If exact tuning matters, it is often best to: - either feed quantized offsets into PlusMix - or send `MIX` into a **quantizer** afterward --- ## With a quantizer This is one of the strongest pairings. Patch: - melodic CV and interval offsets into `BASE/PLS1/PLS2` - `MIX` → quantizer → oscillator Why: - PlusMix creates combinations of voltages - the quantizer snaps the result to a scale Musical result: - controlled melodic branching - gate-switched note changes that remain in key - easy creation of arpeggio-like and modal patterns This setup turns PlusMix into a kind of **melody decision matrix**. --- ## With clock dividers or logic modules Since the `PLS` inputs are controlled by gates, any module producing related rhythms can drive melodic structure. Patch: - divided clock to `SW1` - inverted or offset rhythm to `SW2` Result: - one transposition happens every 2 bars - another happens every offbeat or every fourth note - melody develops in longer cycles This is very effective for: - generative melodies - evolving minimalism - polyrhythmic transposition --- ## With sequential switches or gate sequencers A gate sequencer can decide exactly which notes get altered. Patch: - gate sequencer channels → `SW1`, `SW2` - offsets at `PLS1`, `PLS2` Result: - deterministic melodic editing on a per-step basis - very efficient for creating: - passing tones - octave pickups - phrase-end lifts - recurring motifs --- ## With envelopes and VCAs in parallel Use PlusMix for pitch variation while related gates also trigger articulation changes. Example: - `SW1` gate adds +12 semitones to pitch - same gate also opens a brighter VCA/filter envelope Result: - when melody jumps, timbre also changes - leads sound more intentional and expressive That is a strong compositional trick: **pitch accents aligned with timbral accents**. --- ## With sample & hold or random voltage Patch a stable melody into `BASE` and use random or semi-random voltages as occasional additions. Patch: - `BASE` = core melody - `PLS1` = sample & hold voltage attenuated to a small interval range - `SW1` = sparse random gate Result: - occasional melodic decorations - controlled unpredictability - very useful for ambient, IDM, and generative patches For tonal music, a quantizer after `MIX` is especially recommended. --- # Practical melodic patch ideas ## Patch 1: Two-level transposing lead **Goal:** create a lead that changes shape over time. Patch: - sequencer pitch → `BASE` - fixed +1V → `PLS1` - fixed +0.167V or +0.333V style interval source → `PLS2` - slower gate pattern → `SW1` - faster accent gate → `SW2` - `MIX` → quantizer → oscillator What happens: - the base melody is always present - some notes jump an octave - others are nudged into another interval - some notes combine both offsets Use: - techno leads - modular arpeggios - melodic electro sequences --- ## Patch 2: Verse/chorus melody switcher **Goal:** create structural change from one melodic line. Patch: - main melody CV → `BASE` - chorus transpose amount → `PLS1` - ending phrase lift → `PLS2` - manual or arranged gate → `SW1` - phrase-end gate → `SW2` What happens: - verse plays dry - chorus activates a transposition layer - phrase endings gain an extra lift This works very well in live performance because the module is immediate and compact. --- ## Patch 3: Generative melodic mutation **Goal:** one melody that evolves without losing identity. Patch: - quantized sequencer → `BASE` - random stepped CV, attenuated → `PLS1` - fixed interval → `PLS2` - Euclidean rhythm → `SW1` - clock divider → `SW2` - `MIX` → quantizer → oscillator What happens: - most notes follow the original melody - some are altered by random decoration - some receive predictable structural transposition - the line stays coherent but never static --- ## Patch 4: Manual harmonic lift for live sets **Goal:** hands-on melodic arrangement. Patch: - sequence → `BASE` - +7 semitone equivalent CV → `PLS1` - +12 semitone CV → `PLS2` - leave `SW1` and `SW2` unpatched - use `SW1PL` and `SW2PL` manually What happens: - switch 1 adds harmonic lift - switch 2 adds octave lift - both together create a stronger section change This is simple but highly playable. --- # Strengths of the module for melody ## Very compact At **2HP**, it adds melodic decision-making without eating valuable space. ## Good for pitch CV The manual specifically notes **high-precision CV mixing**, which is critical for melodic use. ## Gate-controlled variation Instead of just mixing everything all the time, you can make melodic additions happen only on chosen steps. ## Manual + patch programmable It works both as: - a hands-on performance tool - and a fully patch-controlled melodic utility --- # Limitations to keep in mind ## It is a unity mixer, not an attenuating mixer The manual describes it as a **unity mixer**, so the incoming levels are summed as given. That means interval sizes must already be correct before entering `PLS1` or `PLS2`. If you want exact semitone intervals, use: - precision voltage sources - quantized pitch rows - precision offset generators - or a quantizer after the mix ## Only two switchable add layers You get: - one always-on base - two conditional additions That is powerful, but still intentionally simple. ## No built-in quantization For melodic tonal work, a quantizer after the output may be the best companion. --- # Bottom line **PlusMix is a small but extremely musical utility for pitch-CV composition.** Its best melodic use is to take a stable pitch line at `BASE` and then use `PLS1` and `PLS2` as **conditional interval or phrase additions**, controlled by gates. Used with sequencers, quantizers, gate sequencers, logic, and fixed-voltage sources, it can create: - transposed note accents - alternate phrase shapes - octave jumps - evolving generative melodies - manual arrangement changes - precise pitch remixing In a melodic Eurorack patch, think of it as a **gate-addressed pitch recombiner**: a way to turn one melody into several related melodies without losing coherence. [Generated With Eurorack Processor](https://github.com/nstarke/eurorack-processor)