# 2hp — Switch - [Manual PDF](../../manuals/2hp_Switch.pdf) --- [Manual PDF](#) # 2hp Switch: using it for melodic patching The attached manual is for the **2hp Switch**, a **4-in / 1-out voltage-controlled signal router**. It can switch **audio, CV, or gate signals**, and the active input can be chosen either by the **SEL knob** or by **SEL CV**. ## What the module does ### Core behavior - **4 inputs** - **1 output** - Routes **one selected input** to the output - Selection can be: - set manually with the **SEL** knob - changed dynamically with **SEL CV** ### Important specs from the manual - **Input level:** ±10V - **SEL CV range:** ±5V - **CV is added to the current knob position** - **Very fast switching**, low noise - Works with: - audio - control voltage - gates/triggers --- # How Switch helps create melodic components Even though Switch is not a pitch generator by itself, it is very useful for **melody construction**, because melodies in Eurorack are often built by choosing between: - different pitch CV sources - different rhythmic gate streams - different transpositions - different quantized sequences - different audio voices playing melodic material Switch is basically a **decision point** in the patch. It lets you create melodies by selecting which source is currently active. --- # Best melodic use cases ## 1. Switch between multiple pitch CV sources Patch four different pitch-related CVs into the inputs: - Input 1: a sequencer line - Input 2: a random voltage source - Input 3: a transposed copy of the sequencer - Input 4: a slow modulation source into a quantizer Then send **OUT** to: - a quantizer input, then to oscillator 1V/oct - or directly to an oscillator if the voltages are already musical ### Result You get a melody that can jump between four different pitch behaviors. ### Why this works musically This is one of the easiest ways to create: - verse/chorus-like variation - call-and-response melodic motion - controlled unpredictability --- ## 2. Switch between different transpositions of the same sequence A very musical patch is to mult one melodic CV sequence into several processors: - Input 1: original sequence - Input 2: sequence + 2 semitones - Input 3: sequence + 5 semitones - Input 4: sequence + 7 semitones Send the output to your oscillator pitch path. ### Result The same melodic contour is preserved, but the active harmony changes. ### Musical effect This gives you: - modal shifts - chord-root movement - bassline variation - instant harmonic structure from one phrase If you clock the switching rhythmically, you can make the melody outline harmonic changes without needing a second sequencer. --- ## 3. Switch between quantizer inputs or quantized outputs If you have a quantizer in the system, Switch becomes especially useful. ### Option A: switch unquantized sources into one quantizer - Inputs: different modulation/pitch CV sources - OUT → quantizer → oscillator This makes four raw sources become one playable melodic stream. ### Option B: switch between already-quantized melodies - Inputs: four different quantized pitch lines - OUT → oscillator 1V/oct This is cleaner if each source already has a distinct scale or pattern. ### Musical effect You can move between: - stable melody - semi-random melody - arpeggio-like motion - transposed variations --- ## 4. Switch gate patterns that drive melodic events Melody is not just pitch; it is also **when notes happen**. Patch four gate or trigger sources into Switch: - Input 1: straight clock division - Input 2: syncopated trigger pattern - Input 3: random triggers - Input 4: Euclidean rhythm Then send **OUT** to: - envelope trigger input - sequencer advance input - sample-and-hold trigger - quantizer trigger, if applicable ### Result You can keep the same pitch source but radically change the melodic phrasing. ### Why this matters A single pitch sequence can sound like entirely different melodies when the note timing changes. --- ## 5. Switch audio from different melodic voices Because Switch also handles audio, you can patch: - Input 1: sine lead - Input 2: square bass voice - Input 3: filtered pluck - Input 4: FM voice Then switch which voice reaches the output. ### Result One melodic line can jump between different timbres or instruments. ### Performance use This is great for: - live arrangement - fills - alternating lead sounds - turning one sequence into a multi-voice phrase Because the module switches quickly, it can create abrupt, stylized phrase changes. --- ## 6. Create stepped melodic selection with CV over SEL The most interesting part of this module is **SEL CV**. Since the **SEL CV is added to the knob position**, you can offset the range manually and then animate selection with another CV source. Patch a CV source to SEL: - stepped random voltage - sequencer CV lane - LFO - sample & hold - gate-derived stepped voltage ### Result The chosen melodic source changes over time automatically. ### Musical uses - every bar, choose a different sequence - probabilistic melody path changes - evolving motif selection - generative melodic arrangement This turns Switch into a kind of **meta-sequencer**, where it sequences which sequence is active. --- # Example melodic patches ## Patch 1: Four-part melodic phrase selector **Goal:** build a melody from four phrase fragments. ### Patch - Input 1: phrase A pitch CV - Input 2: phrase B pitch CV - Input 3: phrase C pitch CV - Input 4: phrase D pitch CV - OUT → quantizer or oscillator 1V/oct - Clocked stepped CV → SEL CV ### What happens Each incoming control step at SEL chooses a different phrase source. Instead of one linear melody, you get a modular phrase system. ### Great for - generative leads - evolving basslines - non-repeating motifs --- ## Patch 2: Harmonic movement from one sequence **Goal:** use one sequence to imply chord changes. ### Patch Take one sequence and create 4 versions: - Input 1: root - Input 2: +3 or +4 semitones - Input 3: +7 semitones - Input 4: +12 semitones - OUT → oscillator pitch - slow clocked CV or manual changes → SEL ### What happens The same melodic shape moves through harmonic positions. ### Great for - basslines - ostinatos - techno hooks - arpeggiated motifs --- ## Patch 3: Gate-switched melody articulation **Goal:** change note rhythm while keeping pitch constant. ### Patch - Pitch sequencer → oscillator pitch - Inputs 1–4: four different gate patterns - OUT → envelope trigger ### What happens The same pitch material gets different rhythmic articulation depending on which gate stream is active. ### Great for - turning a loop into a song structure - creating fills - live improvisation --- ## Patch 4: Random-but-musical note source selector **Goal:** mix predictable and unpredictable melody sources. ### Patch - Input 1: sequencer - Input 2: sequencer transposed up a fifth - Input 3: random stepped CV - Input 4: slow envelope or LFO into quantizer - OUT → quantizer → oscillator - Sample & hold or random stepped CV → SEL CV ### What happens The melodic voice alternates between stable and unstable sources. ### Great for - generative ambient - experimental melodies - evolving Berlin-school style patterns --- ## Patch 5: Timbral melody switching **Goal:** one melody, multiple instrumental identities. ### Patch - One pitch sequence controls several oscillators/voices - Audio outputs of those voices → Inputs 1–4 - OUT → filter/VCA/mixer - rhythmic CV → SEL CV ### What happens Different notes or note groups appear with different timbres. ### Great for - melodic fills - pseudo-round-robin voicing - choppy electro phrasing --- # Practical advice for melodic use ## Use quantization when switching pitch CV If the inputs contain free CV rather than tuned pitch, the output may jump to non-musical voltages. Sending **OUT** to a **quantizer** makes the result much more melodic. ## Use slow or clocked CV for intentional source changes If SEL CV moves too freely, the routing may change too often. For more musical results: - use stepped voltages - sample-and-hold - sequencer rows - clock divisions ## Use the knob as a bias or range control Because the CV is **added to the knob position**, the knob can act like a manual “center” or source preference. This is useful in performance. ## Great for form and arrangement Switch is especially strong at the **phrase level**: - choose which melody source is active this bar - choose which rhythm drives the melody - choose which transposition is active in the chorus So it is less a note sequencer, and more a **melodic structure and variation tool**. --- # Strengths of this module in melodic systems ## Excellent for: - selecting between melodic CV lanes - switching transpositions - switching quantized sources - changing rhythmic articulation - routing different audio voices - generative melody structures ## Less ideal for: - smooth crossfades between sources - polyphony - direct note creation without external CV/audio sources This is a **router**, not a sequencer or quantizer. Its power comes from how you combine it with those modules. --- # Bottom line The **2hp Switch** is best understood as a **melodic selector and structure tool**. It creates musical interest by choosing among: - multiple pitch sources - transposed variants - different rhythm generators - different melodic voices In a Eurorack patch, that makes it extremely useful for: - evolving melodies - performance variation - generative composition - compact harmonic movement If you want, I can also turn this into: 1. a **beginner-friendly patch recipe list**, 2. an **advanced generative melody guide**, or 3. a **“best modules to pair with 2hp Switch” companion chart**. [Generated With Eurorack Processor](https://github.com/nstarke/eurorack-processor)