# Acid Rain — Chainsaw - [Manual PDF](../../manuals/Chainsaw_Manual_1.1.pdf) --- [Manual PDF](#) # Acid Rain Technology Chainsaw — melodic use in a Eurorack system Chainsaw is a **stereo super-oscillator** designed to generate rich, harmonically dense pitched material. From the manual, it is a **digital oscillator** with: - **3 independent voices** - **7 waves per voice** - up to **21 total waves** - **1V/oct pitch inputs** for each voice - global **detune**, **wave morph**, and **linear FM** - stereo outputs with the internal waves spread across **left/right** This makes it especially strong for melodic duties like: - supersaw leads - stacked chords - unison basses - animated arpeggios - wide stereo pads - pseudo-paraphonic lines --- ## What the module does musically ### 1. Three pitchable voices Chainsaw has three separate **V/Oct inputs**: - **V/O 1** - **V/O 2** - **V/O 3** Each input activates one voice when patched. Since each voice is independently pitch-controlled, you can use the module for: - **single-oscillator unison melodies** - **interval stacking** - **triads and chord voicings** - **parallel melodic lines** A very practical melodic interpretation: - patch one sequencer to **V/O 1** for the melody root - patch transposed copies or separate sequencer rows to **V/O 2** and **V/O 3** - create chords such as: - root + major third + fifth - root + minor third + fifth - octaves + fifth for powerful riffs - suspended voicings for ambient lines Because each voice contains **7 detuned oscillators**, even simple pitch material becomes huge and animated. --- ## Core sound-shaping controls for melody ### 2. Root frequency encoder The encoder sets the root pitch in semitones when the **note** LED is lit. - each encoder step = **1 semitone** - press once to enter **fine tune** mode - fine tune mode = **1 cent per step** - hold for 2 seconds to reset to **C1 (32.7 Hz)** Musically, this is useful for: - quickly tuning the module to your patch - setting a performance key center - creating fixed drone roots against sequenced voices - precise tuning for intervals and harmonic layering --- ### 3. Detune The **detune** knob spreads the 7 oscillators in each voice around the root: - 3 above - 3 below - 1 at root At minimum, they are in perfect unison. As you increase detune, the spread follows a curve that creates the classic supersaw widening effect. There is also a **detune CV input** accepting **-5V to +5V**. For melodic work, detune is one of the most important controls: - **low detune**: focused melodic lines, basses, tighter harmony - **medium detune**: lush leads and chords - **high detune**: trance-style supersaws, smeared harmonic clouds, wide pads Patch ideas: - slow LFO to detune CV for evolving pad movement - envelope to detune CV for notes that “bloom” wider after attack - stepped random CV for phrase-by-phrase variation --- ### 4. Saw-to-square morph The second large knob morphs all waveforms from **sawtooth to square**. There is also a **morph CV input** accepting **-5V to +5V**. Musically: - **saw side**: brighter, buzzy, harmonically dense, ideal for leads and supersaw stacks - **square side**: hollower, weightier, excellent for bass and retro chord textures - **in-between**: animated hybrid timbres that keep melodies lively Great melodic uses: - use an envelope on morph CV for per-note timbral articulation - use a slow modulation source to gradually shift a progression from bright to hollow - automate morph with sequencer CV to make each step of a melody feel orchestrated differently --- ### 5. Linear FM Chainsaw has a global **linear FM input** for all voices, accepting **-5V to +5V** and responding predictably up to **2 kHz**. This is useful melodically for: - vibrato with a sine/triangle LFO - audio-rate FM for brighter, more aggressive harmonic content - subtle motion to keep held notes alive Recommended musical use: - for tonal melodic patches, keep FM **subtle** - use very small modulation depth for expressive vibrato - for more modern/aggressive lead tones, apply light audio-rate FM from another oscillator Since FM affects all voices together, it works well when Chainsaw is used as a chord or supersaw stack. --- ## Stereo behavior and why it matters melodically The 7 oscillators of all 3 voices are spread across: - **Out L** - **Out R** This creates a naturally wide stereo image. For melodic composition, that means: - a single note already occupies space like a layered production - intervals and chords sound large without external panning - arpeggios can feel cinematic even before adding effects You can also use only one output for mono operation, which is useful if: - you want to process the sound through a mono filter or VCA chain - you are building a more focused bass or lead patch - your system has limited mixer inputs --- # How to use Chainsaw for melodic roles ## 1. Monophonic supersaw lead Patch: - sequencer pitch CV → **V/O 1** - gate → envelope → VCA controlling Chainsaw output - Chainsaw **Out L/R** → stereo mixer or stereo filter/VCA Settings: - low-to-medium detune - saw-heavy morph - subtle FM vibrato from LFO Result: - huge lead sound with width and energy - ideal for trance, melodic techno, synthwave, or cinematic hooks Tip: keep detune lower for faster melodies so pitch remains articulate. --- ## 2. Massive bassline Patch: - pitch sequence → **V/O 1** - use one output or both summed carefully to mono/stereo chain - envelope-controlled filter after Chainsaw Settings: - low detune - morph toward **square** - very subtle or no FM Result: - thick, hollow basses - stable pitch with lots of harmonic weight for filtering Tip: too much detune can weaken low-end focus, so keep spread restrained for bass parts. --- ## 3. Three-note chord generator Patch: - root sequence → **V/O 1** - transposed CV (+3 or +4 semitones) → **V/O 2** - transposed CV (+7 semitones) → **V/O 3** This gives: - minor triad: root / +3 / +7 - major triad: root / +4 / +7 Alternative: Use three independent sequencer rows to create changing voicings and inversions. Settings: - medium detune - saw-to-square based on desired tone - slow modulation to detune or morph Result: - instant supersaw chords - excellent for stabs, pads, and chord progressions --- ## 4. Moving chord stabs Patch: - same triad setup as above - gate sequence → snappy envelope → VCA - second envelope or modulation lane → morph CV - optional LFO → detune CV Settings: - moderate detune - bright saw start, slightly more square during decay or vice versa Result: - dynamic chord hits - very effective for house, techno, and synth-pop harmonic parts --- ## 5. Arpeggiated stereo texture Patch: - clocked pitch sources or sequential switching to **V/O 1/2/3** - Chainsaw stereo outputs → delay/reverb Approach: - assign different intervals to each voice - create broken chords over time - use slow detune modulation for motion Result: - wide, immersive arpeggios - complex harmonic movement from relatively simple pitch material --- ## 6. Pseudo-paraphonic patch Since there are three pitch inputs, you can treat Chainsaw as a kind of compact chord/paraphonic voice source. Patch: - three separate pitch streams to **V/O 1, 2, 3** - one shared envelope/VCA/filter path after the outputs Result: - three-note harmonic content with shared articulation - excellent for: - chord memory style riffs - held intervals - ensemble lines Important limitation: This is not a fully separate 3-voice synth voice, because the module provides shared audio outputs rather than independent outputs per voice. So each voice is independently pitched, but they are mixed internally into stereo. --- # Best supporting modules to pair with Chainsaw for melody Chainsaw is an oscillator, so to build complete melodic parts it works best with: ## Sequencers Needed for: - note patterns - transposition - chord interval generation - arpeggios Especially useful: - quantized CV sequencers - precision adders - chord interval generators ## Envelopes and VCAs Needed for: - note articulation - plucks - stabs - swells Without a VCA/envelope, Chainsaw will behave more like a continuously sounding drone source. ## Filters Very effective after Chainsaw because the waveform is harmonically dense. Use filters for: - opening/closing lead brightness - carving basses - creating animated chord stabs - taming high-frequency density ## Stereo effects Because Chainsaw already has a stereo image, it pairs extremely well with: - stereo delay - stereo reverb - chorus - phaser This can turn simple melodies into polished, finished-sounding musical layers. ## Modulation sources Use LFOs, envelopes, random, or sequencer CV to animate: - detune - wave morph - FM amount This is the key to making repeated melodic phrases feel alive. --- # Strong melodic patch recipes ## A. Trance lead - sequencer → V/O 1 - medium detune - morph near saw - subtle LFO → FM for vibrato - stereo delay + reverb after output Why it works: The supersaw architecture naturally creates the classic uplifting lead sound. --- ## B. Minor chord pad - root CV → V/O 1 - root + 3 semitones → V/O 2 - root + 7 semitones → V/O 3 - slow envelope or LFO → morph CV - slow random/LFO → detune CV - long reverb Why it works: The internal 21-wave total architecture makes even static triads feel orchestral and wide. --- ## C. Octave/fifth bass stack - bass sequence → V/O 1 - same sequence +12 semitones → V/O 2 - same sequence +7 semitones → V/O 3 - low detune - morph toward square - mono or centered stereo mix Why it works: This creates a harmonically reinforced bass that stays musical and powerful. --- ## D. Evolving melodic drone - fixed or slowly sequenced CV to V/O 1, 2, 3 - very slow modulation to detune and morph - slight FM from slow LFO - stereo reverb/delay Why it works: Chainsaw excels at sustained harmonic material because of its layered oscillators and stereo spread. --- # Things to keep in mind ## It needs external articulation Chainsaw is a sound source, not a complete voice. To make traditional notes, you will usually want: - VCA - envelope - often a filter ## Detune affects clarity For melodic precision: - use less detune for bass and fast lines - use more detune for pads, leads, and sustained chords ## One shared timbral engine All three voices share the same overall waveform morph and FM behavior. That means it is best thought of as: - a unified chord/supersaw engine rather than - three completely independent synth voices That shared architecture is actually an advantage for cohesive melodic textures. --- # Summary Chainsaw is excellent for melodic work because it combines: - **accurate 1V/oct tracking** - **three independently pitched voices** - **supersaw-to-supersquare timbral range** - **CV control over detune and morph** - **stereo width built into the oscillator** In a system, it works especially well as: - a **lead oscillator** - a **bass voice** - a **stereo chord generator** - a **pad/arpeggio source** - a **compact paraphonic harmonic engine** If you pair it with a sequencer, envelopes, VCA, and ideally a filter/effects chain, Chainsaw can serve as the core melodic voice for a very wide range of electronic styles. [Generated With Eurorack Processor](https://github.com/nstarke/eurorack-processor)